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-   -   1978 Sylvania console problems (http://www.videokarma.org/showthread.php?t=259357)

jg6364 08-28-2013 12:41 PM

1978 Sylvania console problems
 
I have had this set for several years. About a year ago the HV tripler was replaced. Just recently I was trying to play it and the picture is scrambled. The audio is great and if you turn the fine tuning ring the picture will go completely black just when you think it is going to clear up. I'm attaching several pictures and a video What should I be looking for? I pulled a lot of the transistors and cleaned the connections just in case that was the problem but no luck.

https://lh5.googleusercontent.com/-8...-30-10_874.jpg

https://lh6.googleusercontent.com/-6...-32-18_671.jpg
https://lh5.googleusercontent.com/-d...-32-24_603.jpg
https://lh5.googleusercontent.com/-o...-32-32_263.jpg
https://lh6.googleusercontent.com/-Z...-32-51_804.jpg
https://lh5.googleusercontent.com/-x...-32-57_499.jpg
https://lh4.googleusercontent.com/-6...-33-05_906.jpg
https://lh4.googleusercontent.com/-H...-35-20_854.jpg

video http://youtu.be/DWW_RvhQrag

compucat 08-28-2013 02:08 PM

Looks a lot like agc overload. Try backing off the agc control slightly if it has one.

jg6364 08-28-2013 04:25 PM

Quote:

Originally Posted by compucat (Post 3080812)
Looks a lot like agc overload. Try backing off the agc control slightly if it has one.

I didn't see any adjustment but there are two AGC det ic's in the deflector module.

sampson159 08-28-2013 06:12 PM

i have the same chassis set.agc ic s were a fairly common issue with this chassis.i may have an extra module for this.not sure but the 19 inch chassis had the same ic s.turn off the afc and perma tint.try to fine tune it.you can also try another channel if your using a converter box.pretty simple,straight forward sets.no frills,just simple chassis with a really fine crt.love these sets and worked on many of them.

jg6364 08-28-2013 07:45 PM

Quote:

Originally Posted by sampson159 (Post 3080830)
i have the same chassis set.agc ic s were a fairly common issue with this chassis.i may have an extra module for this.not sure but the 19 inch chassis had the same ic s.turn off the afc and perma tint.try to fine tune it.you can also try another channel if your using a converter box.pretty simple,straight forward sets.no frills,just simple chassis with a really fine crt.love these sets and worked on many of them.

I would love to get this set back working. It always had a great picture until this. Let me know if you have the modules or the agc IC . I tried the other things you suggested, nothing worked. If it's the module that I'm thinking it is, the one with the agc det ic then the module number would be 32-41658-3. That IC is IC400 in the diagram and the number is 15-43312-1. I have no idea how to check those. I don't have a schematic or service manual for this set. Any help at all is really appreciated.

Jeff

zeno 08-28-2013 08:12 PM

The set has the look of outside interference to it.
Try a different source if you havent.
Also try reseating the 3 modules & check the IF cable.
Do a little tapping around.
If you post the model & chassis I will pull the manual
& see what its got for AGC, to long ago to remember.

73 Zeno:smoke:

zeno 08-28-2013 08:15 PM

OOPS just noticed E45-01. I will look it up tomorrow.

73 Zeno:smoke:

jg6364 08-28-2013 08:30 PM

Quote:

Originally Posted by zeno (Post 3080844)
OOPS just noticed E45-01. I will look it up tomorrow.

73 Zeno:smoke:

Thanks so much , glad you saw the chassis number LOL. The model number is CL7237P-1

Jeff

jg6364 08-29-2013 08:41 AM

I cleaned the connections on the modules and cleaned the tuner. I pulled up some color bars and switched between channels 2 thru 6 no change.



https://lh5.googleusercontent.com/-R...-26-57_269.jpg

https://lh5.googleusercontent.com/-C...-27-56_744.jpg

sampson159 08-29-2013 08:56 AM

looks more like a horizontal oscillator problem.the first module is known for cold solder joints around the if ground plate.its in the center of the module.the 3rd module is horizontal/vertical.also been known to have cold joints.is this the original black matrix crt?they make a pretty picture when they are good.didnt last long,usually about 3-4 years but still the best picture.a flat chassis zenith with this crt would be the ultimate set!good luck with this set.

jg6364 08-29-2013 09:23 AM

Quote:

Originally Posted by sampson159 (Post 3080882)
looks more like a horizontal oscillator problem.the first module is known for cold solder joints around the if ground plate.its in the center of the module.the 3rd module is horizontal/vertical.also been known to have cold joints.is this the original black matrix crt?they make a pretty picture when they are good.didnt last long,usually about 3-4 years but still the best picture.a flat chassis zenith with this crt would be the ultimate set!good luck with this set.

Yes it's the original CRT. It's dated February 1978, same as the cabinet. I will check the 1st module again. I've checked the third module, could not find any bad solder joints. I even checked the electrolytic caps. They all checked between 5 to 10% tolerance.

jg6364 08-29-2013 10:33 AM

Quote:

Originally Posted by sampson159 (Post 3080882)
looks more like a horizontal oscillator problem.the first module is known for cold solder joints around the if ground plate.its in the center of the module.the 3rd module is horizontal/vertical.also been known to have cold joints.is this the original black matrix crt?they make a pretty picture when they are good.didnt last long,usually about 3-4 years but still the best picture.a flat chassis zenith with this crt would be the ultimate set!good luck with this set.


I found a few cracked solder joints on the shielding but that was it. I fixed those and cleaned another connection on the module pins. At times it plays a little better but still not fixed. Thanks for all the info on this type of set. I really appreciate it.

https://lh3.googleusercontent.com/-B...-39-32_376.jpg

https://lh4.googleusercontent.com/-I...-40-09_543.jpg

The top shielding was removed for the picture below.

https://lh3.googleusercontent.com/-s...-40-43_353.jpg

https://lh6.googleusercontent.com/-z...-42-52_653.jpg

https://lh3.googleusercontent.com/-R...-02-42_603.jpg

Jon A. 08-29-2013 10:41 AM

Keep on trucking, I consider this one a keeper.

The IC in the pic with the shielding removed, it doesn't look to be soldered in, have you re-seated it?

holmesuser01 08-29-2013 11:34 AM

I made a fair amount of money on these Sylvanias. I did service for a rent-to-own business that had around 100 of them, and about 100 19" version sets.

NEVER had a bad CRT in any of them. Fine sets, all around.

Kept a stock of knobs for them. Rental customers were good at returning TV's with no knobs.

Those sockets under the IC's and transistors were not terribly dependable. When I found bad sockets, I'd remove the socket and hard-solder the IC/transistor in place on the chassis.

Try cleaning the pins on the board connectors, and look for cracks around the connectors on the modules.

zeno 08-29-2013 11:41 AM

OK got the Sams.
IC 400 & Q202 are the AGC semis. Also some eletrolytics
C420, 215, 216, & 211. Also C130 1mf probably mounted
on tuner at AGC terminal.
There is NO AGC adjust at all.
Normal range at IF board pins are
TA22 4.43- 11.31VDC
TA21 4.62- 9.56VDC
Tough to call this one could be AGC or IF dont think video.
Hard to tell not being there.........

PM sent

73 Zeno:smoke:

jg6364 08-29-2013 12:44 PM

Quote:

Originally Posted by KV-1926R (Post 3080898)
Keep on trucking, I consider this one a keeper.

The IC in the pic with the shielding removed, it doesn't look to be soldered in, have you re-seated it?

yes I reseated and checked the connection with a meter on both sides of the board to make sure it was getting a good connection in the socket.

lnx64 08-29-2013 01:24 PM

Why have I seen this problem before.

Having a weird case of Dejavu right now.

jg6364 08-29-2013 03:02 PM

Quote:

Originally Posted by zeno (Post 3080909)
OK got the Sams.
IC 400 & Q202 are the AGC semis. Also some eletrolytics
C420, 215, 216, & 211. Also C130 1mf probably mounted
on tuner at AGC terminal.
There is NO AGC adjust at all.
Normal range at IF board pins are
TA22 4.43- 11.31VDC
TA21 4.62- 9.56VDC
Tough to call this one could be AGC or IF dont think video.
Hard to tell not being there.........

PM sent

73 Zeno:smoke:

All I could do with is IC400 and Q202 was clean and check the connections.
C420 is a .22uf cap and it checked perfect.

C215 is 10uf 16V it check 13.8uf so I changed it with a 10uf 50V it checked as 10.3uf.

C216 is 1uf 50V it checked 1.4uf so I changed it with the same that checked as .974 uf.

C211 is 4.7uf 25V it checked 6.08uf so I changed it with 4.7uf 50V that checked 4.97uf

on C130, there were 3 of the 1uf 50V capacitors on the tuner. They all checked 1.31 or higher so I changed them all with 3 new 1uf 50V caps.

TA22 was 4.05V
TA21 was 4.64V

Thanks for all the information. I'm willing to try any suggestions.

Here is the link to a video of it playing after replacing the caps.
http://youtu.be/A7nO-bvzaHc

sampson159 08-29-2013 06:57 PM

from the looks of the photo,it seems to have locked in sync.is this the case?if so,the only issues i see is that it is in need of a set up.purity,convergence,etc.make sure tuner grounds are proper.

Bill R 08-29-2013 07:28 PM

Have you tried replacing IC400 yet? Still looks like AGC problem.

jg6364 08-29-2013 07:59 PM

Quote:

Originally Posted by Bill R (Post 3080969)
Have you tried replacing IC400 yet? Still looks like AGC problem.


I don't have the IC400 to replace. I will have to find it somewhere. Does anyone know where I can find the replacement? It crossed to an ECG820 but I haven't found any yet.

jg6364 09-02-2013 05:56 PM

Well after a lot of cleaning and then a lot of searching for that damn little IC. I finally found an ECG820. Plus I replaced about 15 electrolytic caps throughout the set. The picture finally came back but was WAY out of adjustment. I setup the purity and convergence the best I could. I'm glad this is finally finished. LOL

There was thunderstorm warning scrolling across the bottom of the screen The text was clear but I guess was moving too fast for the camera to pick up clearly.

https://lh3.googleusercontent.com/-B...-28-58_268.jpg

https://lh4.googleusercontent.com/-j...-27-20_526.jpg

https://lh5.googleusercontent.com/-X...-28-09_291.jpg

https://lh4.googleusercontent.com/-Z...-29-27_447.jpg

sampson159 09-02-2013 06:35 PM

glad you got it going!screen shots look pretty good.

zeno 09-02-2013 08:31 PM

Looks like you have a real TV again, I am very proud
of you !

enjoy 73 Zeno:smoke:

Jon A. 09-03-2013 01:53 AM

Oh yeah! :rockon:

jg6364 09-03-2013 08:24 AM

I just want to thank everyone for all of the suggestions. You guys pointed me in the right direction.

Thanks so much

Jeff


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