Coby TFTV3227 Takes Time to "Warm Up"?

[Maxstang]

Re: Coby TFTV3227 Takes Time to "Warm Up"?

For the sake of completeness, here are some pictures of the main board. There is some VERY crappy hand soldering going on here. Anyone hears of SW or HSCON capacitors?






Check out the crappy placement and obvious over heating on this chip next to the processor. Can't read the markings on it at the moment.

[Maxstang]

Re: Coby TFTV3227 Takes Time to "Warm Up"?

It's an eye opener to work on a cheap TV like this. The "ground" is a bunch of foil with adhesive taped all over the inside of the case and and the back of the LCD. The ground wires from the board are simply taped in place on this foil! It makes me appreciate the quality of the Samsung TV I worked on before (bad caps and all!).

[budm]

Re: Coby TFTV3227 Takes Time to "Warm Up"?

That U3 looked burnt or the flux?

[Maxstang]

Re: Coby TFTV3227 Takes Time to "Warm Up"?

It was flux. I was able to clean it off.

I've tried to cold spray and I can't get it to make the problem worse. I've been watching it a bunch today, and it seems the flickering and artifact doesn't go away when it's warmed up as I though. It continues to do it all the time. Bummer.

[Maxstang]

Re: Coby TFTV3227 Takes Time to "Warm Up"?

I've located a T-CON board for less than $20. Think it's worth trying it?

[Maxstang]

Re: Coby TFTV3227 Takes Time to "Warm Up"?

Thought I'd wrap this one up. It was NOT the T-CON. Tried a replacement with no change.

After watching the behavior a little while I began to think it behaved a lot like a video card with cold solder joints on the processor. I had repaired a Macbook Pro with this problem a few years ago, so I decided to give it a go.

I had to remove the heat sink from the processor first. Then I flooded the processor from the edges with low viscosity no clean flux until it ran out from underneath. I wrapped the entire board in two layers of foil, and cut out a hole around the processor. Using a heat gun, I heated the processor up to a little over 400C using a small piece of solder on the foil as a gauge for how hot it was getting. Once the little piece of solder liquified, I heated the processor a little longer hoping it was enough to reflow its solder.

Seems to have worked. Symptoms are gone now. I'm betting this is NOT a long term solution. If it cracked once, it will again. THe build quality of this TV is simply appalling. The LCD itself has a plastic housing with only the face frame being metal. It's marked as an LG part. The boards are screwed into the plastic back and the grounding is handled by foil tape.

Anyway, just wanted to close this thread.