1981ish Zenith System 3

[TVTim]

Anybody know how to fix the right side of this screen?

The model number is faded out so I cannot provide it.

system 3.JPG

[radiotvnut]

I've seen ones that use a 9-160 power supply module do that and it was caused by a bad section of the two-section filter capacitor in the power supply.

[TVTim]

Originally Posted by radiotvnut

I've seen ones that use a 9-160 power supply module do that and it was caused by a bad section of the two-section filter capacitor in the power supply.

Okay, where does someone with limited knowledge even begin to look? BTW, thank you for getting back to me.

[davet753]

I think RTVNUT is on the right path here. If you don't have a cap checker, you can bridge a cap across the filter momentarily and see if that corrects the problem. Those sets are at an age where the filter capacitors are likely starting to go down.

[zeno]

Filter caps common on both 9-160 & 9-181 sets. Caps
usually have lots of puss coming out & you can see it from
the top. It will be the biggest cap on the bottom board.
It may be a hoz or pin problem also.

For model # look on CRT for little tear off labels and on the
plastic frame & inside cabinet. The 9-*** module numbers
actually can help more...............

73 Zeno

[radiotvnut]

If you bridge a cap, do it with the set off. Otherwise, you might get an unwelcome loud "pop" and sparks. I had a friend who would bridge caps with the set on. Once, he bridged a cap and the surge from placing the cap across the cap in the set killed the whole TV.

[TVTim]

Can I bridge the cap by simply taking a wire with two alligator clips and clipping one to each side of the cap? Sorry if it is a dumb question, but this is my first venture in to doing stuff like this.

[radiotvnut]

Yes; but, do it with the set off. Also, make sure the polarity is right. If you wire an electrolytic cap backwards, it can blow up. Generally, the negative terminal is indicated by an arrow looking band with a negative symbol inside the arrow.

[TVTim]

Tag numbers found.tag.jpg

[zeno]

Originally Posted by TVTim

Tag numbers found.Attachment 181246

OK you got a 2nd generation system 3 using the 9-160 board.
First instructions on pulling the 9-160 from the set as best as
I remember. If its been out before some things wont apply.

Remove red key. it is center near rear of set. Often has tape around it.
Turn & pull out.
Remove plugs from top of board 4-5 of them IIRC.
Remove white holder along rear of board.
Remove metal or plastic brace from flyback to frame.
remove little black plastic things along rear edge connectors.
Remove edge connectors.
Push down on the frame at both ends of board the little tabs &
slide board out.
You can flip the board over & reconnect to service it now.
You can NOT put anything in the wrong place without forcing it,
just be careful not to bend the contacts on connectors.
If nothing else you will find lots of cold solder joints, go
over them first. More to follow.

73 Zeno

[zeno]

Jumping or bridging electrolytic caps
You need 2 clip leads & a good cap.
Cap must be equal or greater voltage.
Since most caps dont totally open one of less mfd will work.
You are looking for a cure or vast improvement in symptoms.

"filter cans" come with one - four sections. In other words 1-4
caps in one package.
ALMOST always the negatives are tied together.
This is the outer can part. It has 4 tabs, one keyed in a circle.
The positives are inside the circle. They are marked with triangle,
half moon, square & line.

Turn set off.
One clip lead to outer ring (-). Hook to - end of your cap.
Other lead to section to be tested (+) to + of your cap.
Turn set on & see results. Turn off & remove test cap.

DISCHARGE THE CAP by shorting + to - & enjoy the spark.
Move on to other sections if needed.
With solid state sets it is important to do the discharge between tests
& the hook up while off to prevent damage.

73 Zeno