DVX 51cm tv issues.

Check for a temperature sensitive parts in the vertical deflection area. As the set warms up, the sensitive part(s) start working, but naturally never to proper specs.

You can probably troubleshoot for this with a heat gun and a few cans of freeze spray. Once you locate the defective parts, you can then buy replacements. You can test the components by heating and cooling them to weed out the sensitive ones. Don't be surprised if you find a fair number of bad capacitors this way.

If you are not used to TV servicing, this can be difficult, and is not safe for you to try. It may be a better option to send out the set to an experienced service tech who works on TV sets.

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JANA _____

Problem: When you turn it on, a thick white raster in the middle of the screen flashes on and off at about 2 times per second nothing else is on screen, can hear eht come in and out with the flashing. After a few minutes the raster will litterally grow as you watch it and start flashing faster.

After 6-7 minutes it will come straight on like normal except the picture at the bottom is scrunched up 1/3 of the screen and will gradually grow down until a full normal picture is displayed.

Once running it will run flawlessly.

Now I do more work on dvd players and audio equpment and rarely look at a television's, I got this with a whole lot of gear yesterday for $20, no surprise it wont work perfectly but when its warmed up the picture is damn good.

When I get home I will try heating the powersupply/hv section with a hairdryer. Already gone over it for bulgy caps and cold solder but came up without much writing home about.

Has anyone got some tips that I should try on here?

Joe.

Im reasonably comfortable with working on televisions, just havent done a lot of it. last time I worked on one I had two of them to get one going, one had a burnt tube (TAB screen) and the other didnt do anything. swapped the main pcb, tidied up some dry solder, all good.

The freezer spray, I have heard of this but never used. Is it conductive? Corrosive? any major negative effects?

I will try the heat gun tonight to get me in the right general area of the set. It looks like it has been worked on before, Traces on the transformer in the power supply section have been cut and soldered up again.

Joe.

JANA wrote:

well...

Found a few potentialy dried out electro's there is a whole row of them up against the HOT's heatsink, one is against the HOT itself I will replace the ones that aren't measuring up to standard and try again.

j.