Found a Sylvania SS/Tube hybrid
 

http://i.imgur.com/J2YsicB.jpg

http://i.imgur.com/tqscm59.jpg

http://i.imgur.com/k4g1NP6.jpg


I almost didn't bring this home. I debated, then I wiped off the dust to get a better look at it. Apart from being dirty, the cabinet appears to be in excellent condition. I think the top is scratch free, which would be amazing! Also it's made from real wood, no chipboard here.

So I dragged the heavy sonofabitch home and made room for it.

I haven't gotten too far into it yet, apart from a quick cleaning, taking a few quick pics, and a powering on test. I'm thinking this could be a winter project for me, if all goes well financially. I'd like to get an idea when this set was made and what issues they commonly have/how reliable they are. This one briefly powers on before the circuit breaker in it trips.

The pictures aren't showing up :(

Guess I am not the ONLY one...who noticed that....

Changed links to imgur. try refreshing...

I tried uploading them here and linking in the post instead of having them as attachments at the bottom. Well it worked for me anyway...

SO...you have a D-12 chassis. I have one too. About 1968-69'ish.

Think it has about 8 or 9 tubes..INCLUDING a shunt reg and HV rect tube.H-out, damper and V-out.osc all tubes too. As is the video out and color amp.

IF, and audio are FULLY SS. Uses one large-TO-66 transistor for a_out, front of chassis, left side.

GREAT catch...I waited WELL over 30 YEARS...to get the one I have now !!

Get us some "nudies" of the chassis...if you can do so.

WE ALL enjoy "chassis porn" here !!

Will do tomorrow, and some better pics. Took these very quickly before wrestling the beast inside.

Any idea what might be causing the internal circuit breaker to trip?

D12 was a good chassis.
Usually tripping breaker is diode in bridge shorted.
If one is bad change all four.
If there is no loud hum then it may be just a weak breaker.
If it breaks after 2 or 3 mn look tward hoz out / hv area.
All of us looking forwards to working on it with you.

73 Zeno:smoke:

Almost the same type of design that my old Zenith solid state 1971 I had ( The cabinet )

Ah, there is a loud hum for the split second that it operates.

I'm not familiar with changing out diodes, apart from knowing that they go in one way and their basic function is to limit current to flowing only one way. Is there a specific rating scale for them like resistors or capacitors? Can I substitute diodes from one of the various TV chassis boards I have lying around?

Put in ecg 125 diodes and you will be FINE. I PROMISE...(in the power supply anyway)

ECG125 is is 1000 V 2.5 amp. will sub most rectifiers BUT
not quite on a few solid state sets. So we used
ECG156 1000 V 3 amp. A little tougher & a little more $$
If thats what it is you could get 10 packs and have spares.
Common problem, we ordered them by the 100.
Next step is see if thats it or something else is dead shorted like
a big filter can.

73 Zeno:smoke:

Cheaper to buy 1N5408 3A, 1000V diodes - 39 cents for one. They are overkill - you could also use 1N5406 or 1N5407...

NTE and ECG parts were just remarked parts - the generic 1N's are usually cheaper.

Since I never want to replace the diodes again, I'll go with the biggest meatiest ones that I can put in there.

BTW: More pics:

http://i.imgur.com/F9jBA8w.jpg

I swear the cabinet design of this TV screams "GRANDMA'S TV!" Now my Grandma never owned a set like this, to my knowledge, but had things gone differently this would have not looked at all out of place in her house or apartment. And seeing as she had a good bit of thrifty Scot in her, if this TV was cheaper then a comparable RCA or Zenith at the time, yeah she would have bought it.


http://i.imgur.com/qMtJe0r.jpg

I cleaned up the top with a good bit of furniture polish. The top has some light scratches and other small imperfections, but considering it's 45+ years old and looks like original finish, it's in excellent shape! :thmbsp: I doubt anything was directly set on top of this TV. I imagine the person who owned it, I keep thinking it was a grandmother, had various doilies and coasters on it, on top of which sat various knickknacks.

And she would have beat her grandkid's asses if they set anything on top of the bare finish, because she paid good money for that TV, dammit!

Well, before I set anything on top of it I'll put a towel over the top to protect the finish.


Chassis shots:
http://i.imgur.com/t4GbZVy.jpg
http://i.imgur.com/aXiPaxV.jpg

These were taken after I spent time and a lot of Q-tips removing a good bit of the dust inside.

And I found out the flyback can be accessed by raising the door on the cage:
http://i.imgur.com/0Sjx7uP.jpg

And it looks in damn good shape!

Great catch! I stuck it out with similar set recently until I fixed all the issues with it for another VK member. Looking forward to the play by play.

Sylvania color sets have quite a fan club at VK!

I can see why. this chassis looks like it has removable transistors. that and the boards are modular, making tracking down issues easier.

Also good to know that the folks here have experience with sylvanias.

A D12 Sylvania with a solid wood cabinet, very nice. I recall Ron, a.k.a. sampson159 saying that the D12 was introduced at the time Sylvania gave notice to the industry that they would make the best color TV.

I love my '79 with the E48-2 chassis. My only gripe about it is that the cabinet seems cheap.

Well I think I have a clue as to why the TV won't power up. I pulled the chassis to get a better look and...

http://i.imgur.com/a0VduVy.jpg
This ceramic cup wasn't attached to what I assume is the rectifier tube.

The cup is a very loose fit, so I examined it closely to try and find out why:
http://i.imgur.com/D9ImNAh.jpg

It's hard to tell from the pic, but the metal connector inside the cup is discolored, my guess is from electricity arcing. The metal tip of the rectifier tube is very dark.

So I wonder if that tube is still good? perhaps bending the contacts on the connector for a tighter fit might do the trick?

Edit: Nope. Same deal. Works for a second before the breaker trips.

Where are those diodes located? Perhaps I can pull them out and test.

this was the set that started sylvanias drive to the top.very,very good sets and a preamble of things to come.the next was the famous d16 series.same tuner as yours with a really fine crt.then came the best of them all,the d16 slide control.absolutely the best hybrid set right beside the zeniths of the era.excellent crt,simple designed chassis and nice cabinetry.they were also priced about 100.00 less than the zeniths and rca sets.sadly,they are gone now.in the shop days,the margin was 5 sylvanias to every 1 other set.in the southend of colunbus,we had the largest sylvania dealer in the country.

Nice set. I have one with the same chassis but the cabinet is trashed. The tube in your pictures is not the hv rectifier, It is a 6bk4 shunt regulator. The plate socket in your set will have to be replaced. The wire and cap are cooked and it will arc over if you use it. Also you will have to plan a play date with a soldering iron. re solder all the tube sockets and bad connections on the boards. Replace the power filters and breaker if replacing the diodes does not work.

I will pull the manual tomorrow & see where diodes are.
The plate cap you can pull off any set with a 6BK4.
There are many of them.

73 Zeno:smoke:

Cool.

And there may be many plate caps where you are. Me? Not so much. So for now I've cleaned it up with sandpaper best I can and bent the contacts to make a tighter fit. Hoping that will do for now.

That should be OK for now. What I meant was it was used in a lot of TV's
& you can get one off a junker.

4 diodes are under chassis under the power transformer. Test them first.
If any read shorted clip off one end & test again to be sure.

73 Zeno:smoke:

Right under the transformer? Okay. Maybe after dinner I'll see about pulling the chassis out.

Okay here's a shot of under the transformer. (linked for big)
http://i.imgur.com/TYAlSkF.jpg

I found 3 diodes, and something that looks like it popped, possibly the 4th diode? (look for the question mark near the bottom center of the image)

If it's the 4th diode, far as I know diodes don't just pop like that, so could something upstream pop it?

4th isn't a diode, but your degaussing thermistor lost it's nickle. Dust out things and take another photo if possible - there should be a 4th diode if they are in a bridge.

Degaussing nickel should be an FR191 or a FR291 - and don't buy from the ripoff on ebay. Check Moyers or Talon

Okay, thermistor shouldn't be a big deal, I probably still have one or two from a junked TV chassis that'll work.

Cleaned out some of the dust and got a better pic. I think I found the 4 diodes:
http://i.imgur.com/evv5Qbq.jpg

Now... best way to test these I figure is to clip a lead and put my multimeter on them and see if I get continuity only one way. Best way to do that is to completely pull out the chassis. There's one wire stopping me from doing this, and indeed stops me from completely removing any TV chassis I intend to fix:

The flyback wire.

Before you suggest the screwdriver method of making sure it's discharged, let me give a big NOPE to that! There's got to be a better way to remove it, right?

Two things - the rectifier diodes will check as a regular diode, with front to back resistance one way and open the other, or use a diode test function on your DMM, or just replace them outright with heftier ones - we used 1N5407s because they were cheap and good insurance that you wouldn't have a call back or have to pull the chassis again.

Second - to discharge the anode lead on the CRT - I use a grounded (chassis connected) clip lead attached to a long bladed screwdriver to discharge the CRT, then let it set for a few minutes and repeat. Then I grasp the 2nd anode rubber cup where the wire enters the cup and twist slightly, with some force to one side to dislodge the legs of the anode connector.

Remember -the CRT is what is charged (its a big capacitor with plates of aquadag and a dielectric of glass), and will obtain a "surface charge" just sitting, so always discharge the anode button to the aquadag before doing anything around the CRT.

Hoooo... nope nope nope nope nope! If I have to I'll leave the wire connected and work around it instead.

I take it you've been shocked before, or have a pacemaker?

Do what you are comfortable with - Safety first.

The discharge procedure is pretty much standard - RCA wanted a 56K resistor in series with the ground, but later made a discharge tool - basically a HV probe with a pushbutton discharge button.

As long as the 2nd anode lead is connected, the cathode of the HV rectifier has juice on it, and still poses a danger if you are working near it.

I've been bit a dozen times and never had any ill effects - just an adrenaline kick and a few choice words. :grumpy:

Actually no I've never been shocked before. Been repairing CRT TV's for 10+ years, never been shocked once.

Because I knew early on that CRT's pack a nasty punch, so I just leave the wire connected and work with the chassis inside the set... or desolder the flyback from the board. Since that's not an option I'll work around it. Pain in the ass, but it won't leave me lying on the floor twitching...

Okay very first diode I clipped reads as a dead short in both directions. I think I've found the problem. I'll have to put this on hold until I can spare the cash to order some diodes. Unless I can substitute some from a junked TV chassis. Problem is while I know how to read resistors and capacitors, or can look them up easily enough, I have no idea how diodes are rated and what ratings matter...

Like I know you can replace a capacitor with one rated for a higher voltage so long as the capacitance is the same. You can replace resistors with higher wattage ones so long as the resistance is the same. What about diodes?

C'mon...I have been knocked on the ground a FEW times...ALL by the HV of a set. I have been ALSO hit by a boost converter--(around 400 Vdc), H-out cap and focus voltages. It is NOT that bad really. NONE of those...have discouraged me from loving to work on this stuff...old and NEW.

Just an unfortunate aspect of this hobby--or profession...

PM me your address and I'll send you 4 diodes - beefier than the ones you have in the set now.

With rectifier diodes, you can go up in current and voltage handling capability. The diodes in your set are probably 400V, 1A diodes, maybe 600V, 1.5A diodes. As long as the voltage rating of the diode (PIV, or PRV) is higher, you can use the diode. Same goes for the max current rating or IF (I-forward). Higher is better, but please make sure there is a fuse around if on the secondary of a transformer - transformers are the one thing we don't get to upgrade easily, and they can be taken out by shorted rectifiers if not fused.

Unfortunate, yes. But each of us has our limits, and with safety as the primary concern, I fault no one for extra caution.

I've seen guys get shocked, shake it off, and drop dead within hours - their hearts damaged by enzymes that elevate after a shock. Likewise, I've seen first hand the nerve damage done by boost voltages - it was my Dad, and he had nerve damage that lasted for years, with white tissue scarring all along his arm where the voltage traveled along. He couldn't pick up a coffee cup with that hand for 6 months, and the shooting pain (actually nerves repairing connections) went on for months. The scarring took years to disappear.

So yes, let's be careful and mindful of safety at all times. And please fault no one that goes the extra mile to be safe. I'd rather read of their fortunes than misfortunes....

Exactly. Taking a full 15 KV of HV is no badge of honor. Had rca2000 been hit while his heart was at a certain spot in its beating cycle, he'd have gone into afib and likely died.

I like to blow things up and set things on fire. Never had a fire get out of control, and never damaged anything I didn't intend to with an explosion.

Same principle applies to doing my own electrical work. Again, never been shocked, never caused the house to burn down. Actually saved the house from burning down once because I kept getting a faint whiff of smoke and traced it to aluminum wiring for a light fixture twisted onto copper wiring. The connection had corroded and was close to starting a fire. So I rewired the fixture using proper copper wiring.

It all comes down to giving dangerous things a healthy respect and not touching them unless I know what I am doing. And with discharging a CRT, I'd be too nervous to keep a steady hand and would jump at the slightest pop, possibly causing the screwdriver to go somewhere it shouldn't.

So I'll work around the problem. Luckily these diodes are on the opposite side of the chassis, so I have room to get to them.

Well, BE SAFE guys !!,, don't be stupid when you repair your TVs.. No need to know if the current is okay by touching something around the HV cage or else with your hands ouff !!..The warnings are there to be respected when the TV set have need to be repaired...Sorry my English not good .

I assume you want to pull the chassis out ? Usually
you can flip it on edge & run it. Just dont put strain
on the wires. Can usually put a box behind the set
to rest it on. Alternitive is flip the whole set on its side
HV area down & you can run it & do tests. Sets with bottom
plates like Zeniths are almost always done that way.
Just remember the purity will be way off, thats normal.

One other important thing. Until you change the thermistor
JUMP IT OUT or the VDR will burn. They stink too !!!

On HV shocks be as careful as you wish. If you are
healthy it should not harm you but.......
I have got nailed many times by HV. Worse it did
was give me A-fibs for maybe 20 sec. a few times.
In fact if you already have A-fibs it may cure them if
the timing is right !
When they fix them they put a ground on your back
then on your chest. The machine has a sync curcuit &
at the right point SNAP ! And you are back to normal
rhythm often. You are asleep during it. I had it done
3 times.

73 Zeno:smoke:

I use a HV probe for that. Nothing to it, just watch the needle climb and quickly drop.

Good to know. I'm assuming I can throw in a thermistor from any BPC set of a similar size, right? If so, then I have a replacement on hand already.

MAYBE so find an exact replacement. Its 125 ohms cold.
syl p# was 38-17071-2 It will cross to a workman ?FR922?
For now just short it out & repair the set. The degauss just
wont work.

73 Zeno:smoke:

Are you sure about shorting the leads together? I ask because the last thermistor I replaced, shorting the leads would have fried the degauss circuit. This was on a much newer RCA CTC... 187 I believe, but I figure a degauss circuit works pretty much the same?

If shorting the leads together is safe, I'll do that.