1988 27 inch Sony Trinitron, rescued from the trash.

[MRX37]

Replaced all the caps around the IF tuner. Didn't do anything.

That's it. Barring something else to try, I'm done with this TV. I'll probably end up stripping it for parts.

I'll give it a few days, and if I can't think of anything else to try, I'm giving up on this one.

[radiotvnut]

It could be a defective AFT coil itself. I've seen those metal cased adjustable coils in other brand sets go bad. I'd would not scrap the set just yet. If all else fails; you could run your VCR, cable box, etc. through the AV inputs.

[MRX37]

My intention is to eventually sell this TV. If I didn't have a better one, I would indeed use a VCR to compensate for the tuner issues.

How would a bad AFT coil make a picture come in, then go out, then come in again, as if the tuner was unstable?

To clarify what I mean: The best I've gotten it is where a channel has a nice and clear picture, then interference lines appear until the picture is overwhelmed and goes out. Then a split second later the picture comes back nice and clear again. Then the interference lines appear again and it goes out again. It does this over and over.

[Eric H]

Is your picture going black or just blank white raster?
If it's going black you need to check the horizontal drive transformer as suggested earlier, also solder the connections on the flyback and the board on the back of the CRT.

These sets were notorius for bad solder joints.
My 1990 XBR had the horizontal issue when it was 2 years old, it took me three tries to finally find the bad connection but it's still working to this day.

[MRX37]

No, the picture does not go black.

It's like... It's like on an older dial set, where if you turn the fine tuning dial, the picture goes out, turn it back, and the picture comes back. Only there is no dial to turn on this TV, and it does this every few seconds.

The picture is perfectly fine and stable in composite video mode. Also I checked all the transistors with heatsinks mounted to them, and their solder connections look fine. Checked the flyback as well. It's fine too.


EDIT: Here's what I'm going to do: Tomorrow I'm going to swap the main IF can with the PIP IF can. Both cans are nearly identical, and have the same amount of coils and connections in the same places.

It will tell me if it's the IF can/coil/whatever, since the PIP tuner works fine.

If it is a bad tuner/coil/IF can, then having it on the PIP board will make it a lot easier to work on, since removing that board is easy.

[Kiwick]

Sounds like you might have a drifting varactor voltage to the tuner, so check for bad solder connections and leaky caps around the microcontroller chip.

Keep in mind that an apparently good solder connecton with a barely visible ring on it is a bad one...

[MRX37]

I swapped the IF cans. There was a change, but the picture was still drifting in and out.

I'm done with this TV. Trying to fix it has become ***FAR*** more trouble then it's worth to me. I'm going to give it to a electronics recycling center. They'll either fix it, or recycle it.

I can do no more with this patient.

I fix TV's as a hobby, and it's supposed to be fun. I sell em for pretty cheap ($10-15, maybe $20 for a decent one), because I mainly fix em just to see if I can. Trying to fix this TV is no longer fun. It quit being fun around the third time I desoldered the main IF can to futz around with it somemore.

EDIT: Okay. It's gone. Now the recycling center can do what it will with it.

[fujifrontier]

screw the tuner. use the AV inputs!

[radiotvnut]

Sometimes, you have to draw the line especially if you are planning on selling the TV. When I was a kid; I would almost never give up on a TV. Now, there is virtually no decent resell market on used TV's and it's really not worth spending much time or money to fix one unless you plan to keep it. I have several nice looking later model sets that no one wants. They all just sit in my building and take up space. Most people expect to get a 27" set for $25 or less and it must look new and have a 5 year warranty on it! And, you can forget about consoles & anything smaller than 25". People just don't want them anymore at any price. I still will mess with a new set; but, I usually will not fix it if it's going to cost much money. Thank goodness for junk boards.

[MRX37]

Originally Posted by radiotvnut

Sometimes, you have to draw the line especially if you are planning on selling the TV. When I was a kid; I would almost never give up on a TV. Now, there is virtually no decent resell market on used TV's and it's really not worth spending much time or money to fix one unless you plan to keep it.

Yeah. Especally with the 2009 switchover to digital coming closer. I sometimes find TV's that work fine, usually sitting next to an empty box that contained a HDTV inside it.

And fujifrontier: If I didn't have three other TV's that are as good or better then that one, yes I would have hooked a VCR to it and used the AV inputs. As it is, I have a 27 inch TV that has S-video and composite inputs, a working tuner, and audio outputs as well as functioning speakers. I have another TV with all those features, and it's a 36 inch TV. The Sony had speakers with rotted surrounds, no S video, and it was a HEAVY beast!

Believe me, I tried to save this one, but like radiotvnut said, sometimes you got to draw the line.