Sony KV-4000 restoration

[Jonathan]

I recently received a Sony KV-4000 from ebay. I really like this set. The seller said it was in decent condition, but what a lie. The pushbuttons were shot (this seems common on sony sets like this), the right corner on the screen has a reddish area on it(looks like it needs to be degaussed), I heard internal arcing probably from the flyback, and the case looks like it's falling apart. Also, the power supply filter cap in the AC power supply is bulging as well.

So, I'm going to replace the pushbuttons, socket all the ICs, and replace/clean the controls. What else must I do to this set so it is reliable and operates nicely. The color is off as well, is thast due to bad components or off adjustments.

Thanks.

Jonathan

[Chad Hauris]

I would not mess with IC's unless a problem is indicated in a specific one...you are likely do do more damage than good to unsolder them and install sockets and reinstall.
Would be a good idea to check caps for ESR value and replace bad ones.

[Eric H]

Hi Jonathan, I have one that I got off eBay also, works and looks great but the buttons on it don't work right either. Someone said it's a rubber part in the microswitches that goes bad.

If you find a proper replacement for those switches please pass along the part number so I can get some too!

Eric

[andy]

Post a picture of the switches. I have some that that might fit (saved from the various sony TVs that I've parted out over the years). I think there was a bad lot of switches because I've only seen one (projection) set that needed all the switches. Every other sony I've seen with those switches was fine. The few good switches in that projection TV failed after only a few pushes.

I agree that it would be a really bad idea to socket the ICs. IC sockets are MUCH less reliable than the ICs in them. NEC socketed the ICs in some of their TVs which caused all kinds of problems. The fix was to remove the sockets and solder the ICs directly to the board.

[Jonathan]

Thanks guys for teh replies. I won't socket the ICs then. The buttons are made by Toko Japan. It's sealed, so it's impossible to get inside. I ordered some two lead SPST tact switched from mouser, I'll let you guys know what works. What can I use to degauss this tube?

Thanks.

Jonathan

[bgadow]

A soldering gun (not soldering iron) will work in a pinch to deguass. Rotate it around the screen with the trigger pressed, then gradually back away from the set while you are rotating it, making sure you are back away from it when you let go of the trigger. Something else that works good if you have it is a bulk tape eraser.

[Jonathan]

Thanks. I'll give that a try.