On the topic of Sylvania TV's-Snapping sound

[Keefla]

Ok, Since we've recently been talking about Sylvania TV's I figure ill throw this question out there. I bought a Sylvania TV from a yard sale back in 97 or 98 for 5 bux cause the speaker was no good. It's model CA8112WH, 12", Manufactured APR of 78. I replaced the speaker and used it for a bit till the tint and color controlls started flaking out. I replaced the Pots and it worked great untill about the summer of '04 when one night as i was watching it i heard a loud snapping from the TV along with a disturbance in the picture similar to what lightning would do. it was 3-4 loud snaps (like arching). the TV kept playing but i shut it down right away. Leading up to this there was always a sizzleing/buzzing (faint but there) noise when the set was on, after this incident I unplugged it the let it sit for a few days and pulled the back off. I found the HV cable looked charred in one spot like it *may* have arced through to the chassis, but i wasnt sure. I had a guy take a peek at it and he said something about he re-routed the HV lead. The TV worked after that but the picture was kinda odd, like you could see the shadow mask grid (like looking through a screen winow) imposed on the picture. I pulled the back off to see what this guy did and he just looped it around and zip tied it So Im guessing that its casuing a magnetic field and messing up the picture. This was all back in '04, and Its only been on for about 5 minutes total since it acted up, that includes when i got it back from 'Mr. Fix-it '. Anyway I will try to post pix of the HV lead, and shots of the chassis for you to maybe pick out something I missed, but I kept the TV for the one reason that the picture on it was AMAZING!! The way everything looked on it was awesome, best picture of any set ive ever owned, so much so that ive hauled it with my when i moved even thow it didnt work. I cant bear to get rid of it in hopes a satasfactory repair can someday be performed.

Help Help, you think im on the right track? Or no? Any common issues with those sets?


Thanks all.

[andy]

I saw a lot of Philips made Sylvanias with bad triplers. They would crack and arc to the chassis. They were ok if the crackes were sealed with RTV silicone. If the HV cable was arcing, a similar fix should work. There won't be any magnetic field from the HV cable because the current is so low. I would guess that the yoke, or purity rings were knocked out of position.

[Eric H]

Sounds like a HV leak somewhere.

I had a Philco solid state set back in the 70's that would snap horribly every once in a while, make you jump out of your seat it would, it would ruin the CRT after doing it a half dozen times or so, I got rid of it after the second CRT. Found out later it was a bad CRT socket arcing across the focus pin or so I was told.

[sampson159]

lots of 523 triplers were used in those sets. at one time they were under 10.00! rtv silicone,ge clear silicone,all good stuff. in the 70s ,sylvania had the best picture-zenith had the best quality. zeniths are still out there but where are the sylvanais?

[wa2ise]

Originally Posted by sampson159

in the 70s ,sylvania had the best picture-zenith had the best quality. zeniths are still out there but where are the sylvanais?

I have one here

It needed the tuner connections inside resoldered, but otherwise it's held up quite well. It was made in Nov 83. Good picture.

[radiotvnut]

Originally Posted by wa2ise

I have one here

It needed the tuner connections inside resoldered, but otherwise it's held up quite well. It was made in Nov 83. Good picture.

The picture of that set brings back a memory of one a lady gave me years ago. It was a Philips / Sylvania set; but, I think mine still had the big plug in boards.

[Keefla]

thnaks for the replies, i knew you guys would have some ideas. Later tonite ill pull the back off and see if I can find the tripler (any pics of one...im a lowley mechanic not an electronics tech). If its cracked Id rather replace it (if i can) to insure reliability. also like to figure out the screen issue. The purity and convergence are still good, just looks a bit fuzzy on parts of the screen (like you are looking through a screen window).

Thanks again guys.

[radiotvnut]

The tripler is easy to spot. Just follow the HV lead from the CRT back down a rectangular block. That block will be the tripler. I believe it has four leads soldered to it. And, I believe crosses to an NTE523A or ECG523A.

[radiotvnut]

Oh yes, did you try adjusting the focus control to correct the fuzzy picture? I've also seen bad triplers cause poor focus.

[Keefla]

Originally Posted by radiotvnut

The tripler is easy to spot. Just follow the HV lead from the CRT back down a rectangular block. That block will be the tripler. I believe it has four leads soldered to it. And, I believe crosses to an NTE523A or ECG523A.

you would be correct. Actually before i even checked this thread i pulled the set apart and kinda used deductive reasoning to find what I assumed to be the tripler, and then googled the part number (sk3306) to find it was indeed the tripler. yes its a big grey box with 4 leads. it looks to be in good condition (ie not cracked). Im going to un-coil the HV lead that the other guy kinda looped up a few times and zip tied to the side of the tripler, ive looked over the entire thing for evidence of arching, unplugged the CRT socket, didnt really see anything that stood out, but ill keep looking. I did find a few broken groung lug solder joints on the board where the metal of the chassis meets, and im going to re-flow the solder there before i power it up. Other than that i didnt see anything on the HV lead, and the cup is firmly attatched to the CRT.

[radiotvnut]

That SK3306 tripler is an RCA replacement for the original. Here's another idea. Disconnect the HV from the CRT and make sure the HV lead from the tripler is firmly connected to the suction cup HV connector. I seem to remember that some of those SK triplers I used to buy in the '90's didn't have the HV connector attached. A new connector was either in the box or I would have to use the original. It may be possible that when your repairman moved the HV lead around, it may have broken loose inside the suction cup HV connector. Make sure you discharge the CRT before removing the HV connector. Just take a clip lead with one end clipped to the CRT ground strap and the other end clipped to a long flat blade screwdriver. Now, hold the screwdriver by it's handle and work the end under the suction cup and make contact with the HV connecion. You may hear a loud "snap" as it discharges and you should repeat the procedure several times to make sure it's fully discharged.

[Keefla]

I wouldnt go so far as to call the guy who messed with this set last a 'repairman', i think thats giving him too much credit. he's a nice guy, but obviously if he really knew what he was doing he wouldnt be at the job he;s at. That being said i see what your saying, maybe he knocked the lead loose. Thats interesting that the tripeler was replaced at some point. I was under the impression that this set was a very low hour set just by the picture quality, but it must have had some love before I got it. Ill check it out tomorrow, thow an initial inspection of the HV cup area showed only what looked like red sticky jelly stuff smeared all over it. what is that?

BTW, many thanks as always, if you cant tell Im very eager to learn and want this set to be back in action.

Just to let you all know if we cant isolate the problem i have absolutely no problem bringing this set to a professional, It will not be junked, Im just trying to save money if it something I can do.

[radiotvnut]

BTW, have you got a chassis or model number? If so, I'll look for a Sams Photofact on it and see if anything jumps out at me.

[Keefla]

i think this is it: e201002-1641351. there is another sticker on the actual chassis inside but half the numbers are covered by another sticker. Model CA8112WH.

[radiotvnut]

I found the Sams (1747-1, 7-78) for your set. It's an E20-10 chassis. I've worked on a few of the 19" sets with a similar chassis and most of them either had bad triplers, bad filter capacitors, or weak CRT's.