Hello everybody. I've actually been a member since when it was still all Audiokarma. Says since May of 2004. Due to school and such I haven't been active for a long time. I've been lurking on the boards for the past month, which I am quite addicted to. I recognize a few from YouTube here...


Anyhow, I have a problem... One I've never seen before. As in the title, it is a Sears console TV, with a Sanyo chassis.

Finally got around to repairing this TV. All that was wrong with it was a bad solder joint on the coil for the power relay. I fixed that 2 weekends ago.

So I went through the entire TV, redid gray-scale, focus, etc. It was beautiful. The TV looks like it had an honest 25 years or so of use on it until whomever owned it had the problem with the power relay. It was very well taken care of. I got it out of a recycling place.

Anyhow, so I also own a Sencore CR7000. I wanted to test the tube with it.

After I had the CRT neck board off, I accidentally plugged the TV back in. For some reason, the logic decided to turn the TV on with the neck board disconnected. I heard the degauss coil kick on and I just hurried up and unplugged it.

So I test it with my CR7000. Amazing, had 100% emissions still on all 3 guns!

So I go to put the TV back together. When I got several nice arcs inside the neck of the tube while sliding the CRT neck board back on. Scared me, but didn't think anything was damaged.

So I plug the TV back in, turn it on, and I hear a bunch of sizzling when I look back and see the neck of the tube lit up bright purple and orange.

I hurried up, unplugged, cussed.... and then got my CR7000 hooked back up to it.

Every time I tried to adjust the tester for cutoff, a big purple flash would happen inside the neck, and the tester would go into protection mode. The purple flashes were happening further up the neck, underneath the convergence/purity rings it appeared, or under the yoke.

So I'm thinking I just screwed tube up. I was very upset because the tube performed flawlessly and had 100% emissions still.
Went back to G1 short test, and now my blue gun is showing a G1 short. I tried clearing it with the tester, no go. I tried gently tapping on the neck of the tube with the plastic end of a screwdriver and ended up cracking it!!!!

Oh I was upset. Nothing I could have done at this point. So I evacuated the tube, and removed it from the TV.


I found another picture tube, one left, at Video Display Corp. It is a 25VFBP22, which is the same exact tube that was in there. So I just paid $90 + $30 shipping. It just came today, arrived without incident, and my CR7000 shows 100% emissions just testing it. It is supposed to be a NOS tube.


So I spent the time this evening putting the CRT back in the TV. Double and Triple checked my connections.


When I went to test it (luckily I still left my video camera recording), I was greeted with this:

http://www.youtube.com/watch?v=KuNydKBpd2E&feature=youtu.be


The TV did not blow a fuse. That was me hurrying up and pulling the plug. And if you notice, it still made a loud pop 2-3 seconds after I killed the power. You can see when it popped the screen lit up.

I'm afraid to even turn this TV back on to just see what it is doing. Was it popping because the CRT is 30+ years old and having HV applied for the first time? I shut it off as soon as I heard popping.
I just hope I didn't screw this CRT up because I'll be out $120.

I've never seen this happen before.

All CRT ground connections are in place. No smells, nothing appears to be burnt.

Is there something I should know about these Sanyo TVs that if a certain component fails/shorts/opens/whatever, it will take out an entire CRT like I have witnessed with the original CRT?

I just don't want to power this back up yet without asking and completely destroy this CRT.

Like I said, it did not blow any fuses at all. This is a new one for me.


If anyone has any advice, it would be greatly appreciated.

Thanks.

Here's my guess as to what happened.

When you tuned it on without the CRT plugged in it charged up the High Voltage, when you plugged the board back in it probably discharged through the grounds on the board.

At some point you cracked the CRT, maybe when removing the tester socket or when you plugged the CRT socket back in.

Plugging it in with air in the CRT allowed High Voltage to jump to the Guns and from there to the Video Board, possibly damaging it.

What I see in your video could be a Ground left off the CRT somewhere, perhaps the strap or spring across the bell of the tube, I have seen new CRT's snap and pop on first start up before.

I would disconnect the High Voltage lead from the bell of the tube and stick the end of it in a Glass Jar and put it somewhere away from the chassi or ground (and away from you), then I would turn the set on and see if it will run as far as sound and the heaters on the CRT lighting up.
If you have a High Voltage Probe you could check and see if it has High Voltage.

If it blows a fuse at this point then you know something is wrong, if it doesent you could plug the CRT back in and try it, double check all the grounds on the CRT and the chassis.

It's nice to see you here, I definitely recognize you from YouTube, without a doubt.

Anyway, I don't have my good headphones, but I thought I heard a electrical buzzing before the zap, like it was building up energy.

Can it be the flyback? The picture flashed when it did that arcing sound, and that leads me to think it was accelerated, possibly by the flyback.

I noticed the Digital Channel display went out right when it started arcing, was that you pulling the plug or did it shut down?

Does this TV have a focus divider in the HV circuit? This will be a big resistor with one end connected to the HV anode lead, one lead will go to the focus connection of the CRT socket, and one lead will go to the focus control. If this focus divider shorted, it would place full 25-30KV on the focus pin of the picture tube and that could very well take out the CRT, as well as the tube socket. Also, take the CRT socket apart (if it will come apart) and make sure there is no evidence of arcing. It's also possible that the HV is running way too high, resulting in arcing and damage to the CRT. Zenith had that problem where the HV would run so high that it would arc and break the neck off the CRT. This was all due to the safety cap in the HOT collector circuit opening. Then, test the new CRT to make sure you didn't ruin it.

Eric,

I will try what you suggested. I will try disconnecting the 2nd anode and try to run the TV.
I double checked my grounds. They really went all out with CRT grounding on this set: There is a flexible ground strap, which connects to the CRT neck board. And this TV has a metal shield with the degauss coil on it all around the tube. This metal shield has one ground wire also shared with a pin on the CRT neck board. And another ground wire which connects to the chassis ground. All of which are indeed touching the aquadag.
Nothing appears to be burnt or out of the ordinary on the CRT neck board. You are right about it building up a charge without the CRT being connected. I've just never seen this happen before.
And also, I pulled the plug after the first pop. That was me shutting the TV down. And then after 2-3 seconds the second pop occurred and you saw the screen light up.
Also, is there any chance, after removing the HV, that if there is a fault elsewhere, can it still take out the guns? That's what I am afraid of...

Brandon,

It was the HV from when the TV turns on. The smaller snaps are normal. And you should have heard the degauss coil as well. The loud pops are what scared me and immediately caused me to pull the plug.


Radiotvnut,

There is no focus divider. The focus wire just comes right off the flyback as its source, goes to the focus pot on the back of the TV, and then up to the CRT neck board as a black wire. A white wire returning from the CRT back down to the focus pot.
There is no evidence of arcing on this CRT neck board.

I have some good news, I hooked my CR7000 tester back up to it.

The guns are still good! Nothing is shorted, and everything is reading 100%.

Now I just need to figure what was causing the loud popping/discharge on the HV.

I'm just really afraid of screwing up this CRT since I just bought it NOS.

Ok, tried some things:

Tested continuity between aquadag and chassis/crt ground. I have about 1k ohms, which I will assume as normal. Direct contact with ground strap to ground is near 0 ohms. So we know we have good CRT ground.

I took Eric's suggestion and powered up the chassis with the second anode disconnected. The TV does still work. I get sound. The CRT heaters are working and no arcing, which is excellent. So I now know at least the CRT is ok. That was my main concern.

I'm done for the night.

Tomorrow shall I try hooking the second anode back up and giving it another try?

This is just odd... The HV popping was pretty loud, but it appeared to be all contained within the CRT, and it only did it twice. Just found it odd that it had that second or 2 delay then popping loud with the screen lighting up like it did.

I was just afraid of ruining a brand new CRT, hence I just had to delurk and ask for help.

I would disconnect both the HV anode and the CRT neck board. Then, I would verify the correct HV and focus voltages as per the schematic. If these are OK, I'd check the other CRT voltages to make sure they are OK. It sounds like you got lucky on not ruining the new CRT; but, I wouldn't press my luck.

I would disconnect both the HV anode and the CRT neck board. Then, I would verify the correct HV and focus voltages as per the schematic. If these are OK, I'd check the other CRT voltages to make sure they are OK. It sounds like you got lucky on not ruining the new CRT; but, I wouldn't press my luck.

Alrighty. Being that I am finally getting around to fixing my vintage television collection after an extended hiatus (I have like 50 vintage sets now), I just went on Ebay and got an HV probe. So I'll test that once I get it in. It is supposed to be around 29-30KV for this crt.

The stickers do not say what the focus voltage should be. I'm going to hunt around for any service manuals for this set then. Problem is I am missing the model nameplate. Hopefully I can go by chassis.

Probably somewhere in the 4-5KV range for focus voltage

The chassis number may be listed in the Sam's Photofact index.

I would like to know if you retested the old tube after removing it? and if its shorted, can your tester remove the shorts? is there any physical damage to the old tube?

If you can clear the short, reinstall the tube, make a new you tube video of the back when you power it up, and see whats sparking. Is it on the socket board? those things had ground wires too, is it on? is the B+ around 125 - 155? does this tv have a trippler? I don't think so, but had to ask. You know its possible you have a bad yoke now... Not really likely, but you need to look at what the sparks could have jumped to. I think its pretty strange you have a bad tube now from that unpowered discharge on an 80's sanyo.

I would like to know if you retested the old tube after removing it? and if its shorted, can your tester remove the shorts? is there any physical damage to the old tube?

If you can clear the short, reinstall the tube, make a new you tube video of the back when you power it up, and see whats sparking. Is it on the socket board? those things had ground wires too, is it on? is the B+ around 125 - 155? does this tv have a trippler? I don't think so, but had to ask. You know its possible you have a bad yoke now... Not really likely, but you need to look at what the sparks could have jumped to. I think its pretty strange you have a bad tube now from that unpowered discharge on an 80's sanyo.

The old tube ended up cracking in the neck after gently tapping on it trying to see if it affected my G1 short reading. So it is now gone to air. That tube is no more. I even busted the end off afterwards and pulled the electron gun assembly out and cannot see where it may have shorted. This is why I needed a new tube.

Just FYI, when the old tube was in there after the problem happened, the TV ran for about 10 seconds before I shut if off after seeing the neck lit up bright purple and buzzing (wondering why I wasn't getting a picture.) There were no HV arcing anywhere. Everything just started up normally other than that problem in the neck.

Now, I tested the TV with the new tube without the HV 2nd anode lead attached. Everything works just fine. Heaters light, everything else is hooked up including all grounds as I've mentioned above (I've checked it 4 times now. With 3 different CRT ground wires, they are all hooked up to their appropriate terminals. I took pictures and took notes before I even disassembled the set.) Everything functions as should be without HV hooked up at this point.


I bought an HV probe meter off Ebay, should be here next week to check the high voltage which should be around 30KV.


All that aside, the only thing I can think to do is try it again. I hurried up and pulled the plug on the first loud snap. After one to two seconds the tube discharged again making that second loud snap. It also scared me because the screen also lit up with it. But if you listen carefully, it also had a bunch of smaller, normal sounding snaps you'd hear upon starting up and shutting off the TV.


I've just never encountered this kind of problem before. If everything works without HV applied, could there be a problem internally with the second anode connection? As in this NOS CRT is defective? Everything else checks 100% on my Sencore tester. The loud snap/pop was internal to the tube, and caused it to light up as well as you may have seen. I had the yoke out after this incident and there are no burn marks or other indications of a failure. There were no burning smells or ozone either after this happened.

At some point you are going to have to try it again with the Anode connected and let it run.
If everything is grounded as it should be then it may just take a bit for the tube to settle in on first fire up.
I recall this happening occasionally when a new color CRT was installed.

It is possible the CRT could be damaged internally even though the guns are fine, the shadow mask could have been dislodged in shipping.

most of the crt,s i replaced nos or rebuilt would snap pop for a couple minutes then be fine. i don,t know the cause but never had a problem with them. i put a nos rca in my ctc68 a few months back and it had a loud snap at first power on nothing after that plays like new. i think your ok on the sanyo tv. steve

It could very well be the effects of a new CRT; but, I'd still want to know what the HV and focus voltages are before going any further. Something caused that old CRT to crack and you want to make sure the same thing does not happen to your tube.

Well, I just went ahead and hooked up the HV to it.

And IT WORKS! It made another loud pop, but about half as loud as the ones in my video. Followed by the normal snapping sounds as you'd expect.

Picture came up and it is working just fine!

Other than you can tell the old tube, despite having 100% emissions, was a bit worn. The screen greyscale is a bit bright, and the focus is a bit off, but much, much sharper at the edges than the old CRT. Even still the old CRT still looked amazing.

So all it needs now is the convergence and it looks like either purity or it needs degaussed in the lower right of the screen.




But as I was getting all excited, the TV decided to shut itself back off and won't come on again. And I know what it is now: That power relay. I've had this TV for 6 years in storage now, and I now remember I did resolder the connections at the power relay to no avail about 4 years ago. I went in and wiggled the power relay and the TV decided to come on! So I resoldered it 2 weekends ago completely forgetting I already did that 4 years ago, and all of a sudden it started working. This was the same night I broke the original CRT. So on with the hunt for a new power relay at this point. Coil appears to be intermittent.


As for the CRT neck cracking on the old tube... I don't know if it had to do with that internal short I got (it was an extremely bright purple when the tube was on) and maybe I accidentally hit the neck wrong with my screwdriver handle trying to see if it made any difference on my tester after realizing I just screwed the tube up. I was not happy that night, and I might have accidentally hit it too hard after giving up knowing there was nothing I could do for that tube... it was toast at that point.



Anyhow, what I just witnessed was a first. I can understand some loud pops from a brand new CRT, but these were extremely loud with those color flashes. It just scared me. But now I know. Lesson learned on multiple things just from this. I will also check the high voltage in this set once my HV probe comes.


I will keep you posted once I get it functional yet again.


Thanks!

This is becoming quite an adventure here....

The problem now is not the power relay. Everything tests fine and put it back in.

Now the digital control board isn't working. Press power, and no voltage (12VDC) is on the coil of the relay.

There is a power regulator there that may be the culprit. Didn't have time to troubleshoot any further.

But recall how I said the TV randomly turned itself on when I plugged it in while I had the neck board off? It did that more than once, and only happens when you first plug the TV in. When it does that, the sound comes on, then slowly fades out, and I have no control. I had to turn the TV off, then back on. One time it did that it randomly started advancing channels on its own. It could have been that voltage regulator failing and putting out the wrong voltage causing erratic behavior.

The microprocessor is a long socketed IC. I think I should look up the datasheets on that and see where the input voltage is fed, and see if that is wrong.

And to make things even more complicated, not only do I not have the model #, I cannot even locate a chassis number. Just part numbers all over everything that doesn't help. I know I need to get a Sams Photofact so I can check other voltages at this point.

It could be multiple things, and I am not going to be able to get back into this set till next weekend.

well, I think your old tube arced through the neck, to the yoke, like zeniths with that bad safety cap. That most likely cracked the tube, and gave you the short reading.

I bet your relay kicking on and off is the HV hold down circuit. If the voltage goes up, the set shuts off. but its only a guess. It was a thing on those sets around that date. Look for a long IC in the middle of the H and V circuitry, and look for a pin with either "hold down" or "0V" printed on it. If you can get the set to run, with the board set for you to measure the 0V pin, if it goes up, ground it temp, to see if the set comes on.

Take the number off that IC and get a pin-out, not as good as a schematic, but you can see the 0V pin.

It did not crack where the yoke was at... I just kept calling the whole piece where the guns are at the neck. It cracked starting from the pins and evacuation nipple. And it was probably because after I gave up on the CRT since it was toast, I might have tapped it a little too hard by accident trying to clear the short.

The purple arcing inside was from whatever damage was cause by that discharge from the CRT neck board. I don't know why that happened, because this is the first time I've seen something like this happen. That did the CRT in right there.

But my problem now is indeed localized to that logic board that controls the digital tuner, power on/off, etc. As I said it was acting up when you first plug the TV in prior to all this (randomly turning itself on with no audio or control). And now it just finally quit working.

When you first plug the TV in, the LED channel display used to briefly light up 00 for like a fraction of a second when it was working correctly. Now it doesn't even do that. I'm suspecting that voltage regulator, or surrounding capacitors, etc. might be bad. There isn't too much to that board. I am going to try to find the data sheet on that micro controller IC and the voltage regulator, and see if at least the voltage inputs on it are correct for standby power. If not that is probably it.

Well after spending last night and today troubleshooting the logic board, I finally found the problem.

Without a schematic, just tracing everything out. Turns out the relay does not get its power from the output side of the voltage regulator (which is 12VDC). It just grabs it from the incoming side which is 16VDC. Uses a dropping resistor in series with the coil to allow it to operate at 12V.

Followed that all the way down to the shorting diode right before the relay coil. Still read 16V. Get to the relay, and with the TV off, fluctuating between .7 and 1.3V at random. Shouldn't be doing that as there is nothing else between the diode and relay. Shorting diode tested good. From the other side of the relay goes to the collector on the switching transistor. Turning the TV on, Base to Emitter was .7V which is right. Collector to Emitter was 0V, which is right. But still that small fluctuating voltage on the coil.

Long story short, I jumped it from the diode to relay and the TV turned on when I pressed power. Apparently there was an intermittent/bad trace on the board. I just soldered a wire in place and now everything is working fine again.




But now, the same CRT problem remains....

The TV still snapped, but not loud like in my video (which I took down because that link was unlisted and just for this site, and somebody was rather rude to me about my TV, telling me to junk it and get a Sony.)

So I let the TV run for a good while. No problems, razor sharp picture. Adjusted the purity and got that looking great. After about 15-20 minutes the tube started to snap again, about once every couple of minutes. Nothing as loud as the original video, but enough to cause the picture to jump and make you turn your head.

Went to do greyscale. Put the TV in setup mode, which is a jumper on the board. I did that with the power off. When I turned the TV on, it snapped again, and I noticed in setup line mode, the neck of the tube where the heaters are at was glowing a slight blue (looked like it was reflecting on the glass though from something further up.)

It got a little bit brighter as I watched it and it snapped again with a blue flash. Then the blue glow went away.


It started glowing blue again after a little while, and I just decided to shut the TV off. I didn't even get to do greyscale. When I shut the TV off, it snapped again, but this time a big blue flash in the neck of the tube.

Now when I was operating the TV normally without the setup line, no blue glow in the tube at all. It ran just fine for about 15 minutes, with the occasional snap here and there. Even shut down fine with no snapping.
While testing it with the test jumper earlier with the power relay problem, I just touched the lead to the relay coil and the TV came on, then I disconnected the lead, turning the TV off after I verified it worked. The TV just gave another snap a couple seconds later with no weird activity in the CRT neck.

Also to note, when I ran the TV without the second anode lead hooked up, nothing bad happened there either. This is only occurring when the HV is applied to the tube.






Just to run down a few things:
1. I cracked the tube on the old CRT. I accidentally tapped it too hard near the pins and that is what cracked it. It was already after the original CRT was beyond repair so really it was nothing to lose at that point. It wasn't up near the yoke or anything.
2. I shut down the TV in the video by pulling the plug as soon as I heard it snap. It wasn't the excessive HV shutdown protection.
3. The original CRT did not have a HV problem at all. The problem was something shorted in the neck of the tube as it affected my Sencore CRT tester. This new CRT everything tests perfect on the tester, and the TV does operate perfectly minus the occasional loud snap. I've only had this CRT on for 15 minutes total. I wasn't going to worry about that
4. What concerns me now is that blue glow and bright flash upon shutdown in the neck of the CRT when in setup line mode. Doesn't do any of that when running the TV normally.



All CRT grounds in place and hooked up. I'm just wondering what is going on here. Everything works as it should when it was on. Picture looked perfect, perfect focus, everything.
Nothing is physically burnt or blown. The CRT neckboard is fine. Picture was the right size and everything.


These are just all things I've never seen before. I got my HV probe, just haven't tested the TV with it yet. I don't suspect that being a problem though. Focus is right in the center of the pot as well.

I am just hoping this NOS CRT is just being funky and will eventually quit doing that. I just can't explain why it was glowing blue in setup line mode like that with a another snap/blue flash in the neck when I shut it down, other than the fact that vertical deflection is shut down (hence the electron beam being concentrated and extra bright), and there is no luminance/chrominance signal present.
This TV has sentimental value to it, and that's why I really want to get it going again.

I did turn it back on after all this in normal mode, and it did not snap one time at all. Picture came up beautifully, no blue glowing. I am so hoping this CRT is just being weird. I just didn't get to do greyscale (which isn't too far off from the old tube, just a little bit reddish at low light). Drives are dead on. I'm wondering if I should just let it run for several hours, get broken in first.
Last new CRT set I bought was in 1996. It did snap a lot (just not like this TV is doing) for about a couple weeks until it broke in. Then it hardly ever did it after that.

It's late and I'll play with this some more tomorrow.

Because after I perfect the greyscale, convergence and purity, this TV should be ready for semi-daily use like I plan to use it for (retro video gaming and being hooked up to the CATV system and Sanyo Betacord VCR).

FWIW, my parents bought a late 60s Zenith rectangular console in '81 or so that had just had a brand new CRT installed and it snapped intermittently with a brief loss of picture (don't know if there was accompanying neck activity) for at least the first 6 months. The tech they bought it from said it was normal behavior, and the set played fine for a decade after that.

FWIW, my parents bought a late 60s Zenith rectangular console in '81 or so that had just had a brand new CRT installed and it snapped intermittently with a brief loss of picture (don't know if there was accompanying neck activity) for at least the first 6 months. The tech they bought it from said it was normal behavior, and the set played fine for a decade after that.


That is EXACTLY what this is doing! Well that makes me feel better :)

The neck activity only occurred in setup line mode... not at all running regularly.


I honestly believe this is the case, and I'm just going to let it run. It has only been ran for 15 minutes total after repairing the relay problem last night. This tube is probably 30+ years old and being powered on for the first time

Good for you for wanting to keep her going :)

I hope you can figure out exactly whats up!

Would be interesting to know the high voltage.

Would be interesting to know the high voltage.

Just checked it. 29-30KV, just as it is specified on the label, so that is OK.

It is also completely steady too.

I caught it when it snapped. There was a bright flash seen through the neck of the tube.

But again, this only occurs when I have HV applied.

But when it does it, it is identical to the symptoms Ischmidt mentioned. And it does it at random.

Otherwise, it is working perfectly.

Check the CRT socket around the Focus pin area, make sure it's not Carbon Tracked or damaged in any way.
If all is OK I'd probably just let it run and see if it clears up.

Check the CRT socket around the Focus pin area, make sure it's not Carbon Tracked or damaged in any way.
If all is OK I'd probably just let it run and see if it clears up.

CRT socket is indeed clean.

Good news is the TV has been on for 4 hours now. The loud snapping actually quit completely about 2 hours ago. Frequency of it happening slowed down to about once every 10 minutes all the way down to nothing at this point.

I am going to let it run all night now since everything else is in check. Hopefully that will break it in so it quits doing that crap.

I used to install rebuilt color tubes and they would often snap and pop for a while then settle down.

The reason I asked about the CRT connector is that I bought a Philco 19" set back in the 70's, it had a rebuilt tube but every so often it would let out a very loud SNAP, after about a month the CRT started getting soft and the grey scale went off, after two more replacement CRTS it was still popping now and then so I sold it to a TV repair guy.
He found the insulation around the Focus pin had gone bad and was arcing HV to the guns, this killed the tube very quickly because it was like being rejuvenated every night for a month. He fixed that an no more popping.

I used to install rebuilt color tubes and they would often snap and pop for a while then settle down.

The reason I asked about the CRT connector is that I bought a Philco 19" set back in the 70's, it had a rebuilt tube but every so often it would let out a very loud SNAP, after about a month the CRT started getting soft and the grey scale went off, after two more replacement CRTS it was still popping now and then so I sold it to a TV repair guy.
He found the insulation around the Focus pin had gone bad and was arcing HV to the guns, this killed the tube very quickly because it was like being rejuvenated every night for a month. He fixed that an no more popping.


Wow heheh. Definitely don't want to kill this CRT that way. But yeah, CRT connector looks perfect.

But so far, it's not doing that snapping/popping/arcing anymore.

I would have expected it once or twice upon startup (just not as loud as what I experienced) but to keep on doing what it did. heh. I just wanted to be sure that this was indeed the case, and letting it run would clear it up. So far it has.

I'll keep you posted what it does tomorrow. Right now it's working great playing Family Guy.

Even got the cable box remote to work with it. Got Ebay setup for Sears TV remotes in hopes I'll find the one that goes with it (I saw it in the 1979 catalog on another TV: It has the full numeric keypad, volume up/down, and power buttons, and was quite wide.)

Thinking about why new CRTs snap crackle and pop: I wonder if it's because there are minute sharp points here and there inside where HV concentrates, and after a while these get burned off? I don't mean actual needles sticking out but just little bumps in the coating and/or on the tube elements. They act like tall trees for the HV lightning to strike. Got to be some reason why the tube finally settles down.

well, with the service switch on, there should be less current drawn on the tube. I imagine also as the picture gets dark, hv would go up, and the tube would spark again... does the hv go up on dark scenes? Maybe you should tone it down a bit?

Well, after an entire weekend of letting the TV run 8+ hours a day, it is safe to say that the very loud HV snapping completely quit.

This new old stock CRT is really looking amazing. TV is working excellent.

And now, the videos:

http://www.youtube.com/watch?v=Kh5JkryHdA4
Setting the TV up with new CRT and a talk about what happened.

http://www.youtube.com/watch?v=avkV4seKtZs
And the demo of the TV along with the 1984 Sanyo Betacord VCR after restoration.



My next project is one of those futuristic Zenith corner console TVs. Mine is an '81 with the System 3 chassis and Space Zoom. It currently isn't working. Just blows the B+ fuse. May be a shorted HOT or diode.

What is odd is both that corner Zenith and that 1980 Sears both had casters mounted on the bottom of them (scored them both out of this appliance recycling place).

Thinking about why new CRTs snap crackle and pop: I wonder if it's because there are minute sharp points here and there inside where HV concentrates, and after a while these get burned off? I don't mean actual needles sticking out but just little bumps in the coating and/or on the tube elements. They act like tall trees for the HV lightning to strike. Got to be some reason why the tube finally settles down.

I remember reading about that once before, and that makes perfect sense. The TV quit doing the loud snapping while interrupting the picture now, and no apparent damage was done when it did snap. Probably had a big enough imperfection in it to cause what I experienced.

well, with the service switch on, there should be less current drawn on the tube. I imagine also as the picture gets dark, hv would go up, and the tube would spark again... does the hv go up on dark scenes? Maybe you should tone it down a bit?

I tested the HV with the brightness/contrast at minimum, and it was a very steady 29KV, which is what the tube was rated for (29-30KV.)

The only adjustment for HV was a 3 position jumper; Normal, High, and Low. It was on the normal pin.

The snapping happened at random, mostly on bright scenes.

Well, after an entire weekend of letting the TV run 8+ hours a day, it is safe to say that the very loud HV snapping completely quit.

This new old stock CRT is really looking amazing. TV is working excellent.Well good buddy im glad you have the will to keep whats better GOING :)

my xl100 19 inch set from 1973 snaps in humid weather.2-3 loud pops and it is fine for days.it is my garage watcher and get used daily.only when humidity is up around 70 percent.winter weather will be a relief!

Wanted to update this thread. The CRT is still working fine after all this time still.

But in the meantime, I kept observing the TV's little quirks, and the audio kept getting weaker and weaker with less bass to the point you had to put it on max with distortion to even hear anything.

So I went all out and recapped the whole TV. Used United Chemicon KMG series electrolytic caps. I found about 6 bad capacitors, two that were completely open, one of which was in the audio circuit. A majority of the smaller value caps were quite marginal on my ESR meter. Only the larger value caps were still good (but I changed them out anyway.)

And now, holy crap does that TV perform now, especially in the audio department. The picture really improved too. So I am quite pleased with the results.

http://www.youtube.com/watch?v=rJYpTz00bFU

This TV should be good to go for a long time now.

And this is one of many future recap projects coming up. As I've mentioned I have about 40+ TVs from 1952 - 1982 that needs restored.

It seems weird that a Solid State set from the 80's needs recapping but I guess they get old like everything.

I was actually thinking about that the other day when I found a 1981 Hitachi Color Set, I realized that the set was 31 years old now, yet I could remember when sets from that era were brand new.

My first vintage TV was an RCA 8-TS-30 from 1948, I bought it around 1980 give or take a year so at that time it was no older than the Hitachi I just got last weekend, yet it seemed prehistoric at the time, the Hitachi hardly seems old at all to me.

I was 20 in 1980, and now I'm 39. :scratch2:

Its good seeing him wanting so much to keep her going and not submit to this new garbage that isnt anywhere near as good! -- WE NEED MORE PEOPLE LIKE US IN THIS COUNTRY!!!!!!!! (And the world also)