New problem 42hl196

[audiofreak19]

So I replaced the three ic and now the tv turns on. Well it turns on and the red light blinks 3 times for about 5 sec then the blue light turns on and the red led stops blinking and turns off. The backlight turns on but seems brighter on the sides then it does the middle. And the backlight stays on for 5 seconds and turns off and then tries to turn back on immediately. But the blue light states on the whole time and q880 keeps getting hot. Does anyone know the voltages of the ic at q880 the strw-6765 I think is the model number. Cause I have no clue where to check. I disconnected the inverters to look for damage but no luck.

[budm]

Re: New problem 42hl196

Did you put on enough heat sink compound when you install the new IC? Toyical VCC for the STW6765 is around 18~19V range, see spec attached. Is the 12V out put steady?

http://s807.photobucket.com/user/bud...?sort=3&page=1

[audiofreak19]

Re: New problem 42hl196

I put quite a bit on there and it's coming out the sides of it. And thanks for the voltage info. I'm wondering if its the connection of the regulator or the seine board going bad. Someone else had the same problem but I never heard if replacing the seine board fixed it

[budm]

Re: New problem 42hl196

I will be working on that TV and the power supply board tomorrow, I took those pictures last week.

[budm]

Re: New problem 42hl196

I checked the voltage, it is 15vdc.

[audiofreak19]

Re: New problem 42hl196

So what did you just put some resistors of the power supply. What value are those resistors.

[budm]

Re: New problem 42hl196

The typical 1 k resistors. I am also trying to figure out why that IC gets so hot, I did not have a chance to check the temp yet.

[audiofreak19]

Re: New problem 42hl196

I tried the resistor thing you did but it didn't change anything. It still does the same thing. Tv blinks red lights for 30sec then blue light comes on with backlight which looks kinda dark in the middle then screen shuts off then comes back on a couple seconds later

[budm]

Re: New problem 42hl196

You use the resistors to test the power supply by itself, not connected to the other board.

[audiofreak19]

Re: New problem 42hl196

Lol oops. I'm like stumped on this one cause I have replaced the regulators and got it to turn on but I don't know why that one regulator still gets hot.

[budm]

Re: New problem 42hl196

The 12V SMPS IC does run too hot to touch, mine is still running.

[audiofreak19]

Re: New problem 42hl196

yea the one regulator thats the most common to go bad the 6765 one heats up and right when it gets to hot to touch the tv turns off and then waits like 3 sec to turn back on.

[audiofreak19]

Re: New problem 42hl196

So I finally fixed the tv. I had to redo the one regulator solder connections and the cause of the blue light and then the back light turning on then back off and repeating was the seine board. I don't know what in it was bad but I just bought a replacement tossed it in and fired right up. It did the diag 3 red light flash only initially after plugging in the tv and then worked like normal.

[dkneyle]

Re: New problem 42hl196

I was just reading through this thread. I worry when I read that the temp of the regulator seems very high and you had a lead that needed to be resoldered. What's the chances that the temp is high enough to melt the solder?

[audiofreak19]

Re: New problem 42hl196

I think the reason the temp was so high because it was probably working extra hard to send the voltage to the seine board which was faulty. I will check the reg later today to see if it still gets hot or not.

[audiofreak19]

Re: New problem 42hl196

And the reason I had to redo the soldering again was because the whole time I was troubleshooting the backlight thig I thought it was te reg causing it. Like maybe I didn't do a good solder job cause it was one of my first component solder jobs so I kept redoing it and it wasn't the problem the whole time.

[audiofreak19]

Re: New problem 42hl196

So I tested the tv and left it on for about a hour and a half and heard a huge pop and tv was off giving 3 red blinking lights. I looked at the connection of the 6765 and one of the solder joints I guess got hot and melted and touched the one next to it. Do u think its fried the strw6765. I'm so frustrated now with this power board. It would be nice to start again with a fresh one but you can't find them anywhere.

[audiofreak19]

Re: New problem 42hl196

So I bought a power supply off ebay and got it and plugged it in and it fired right up cause it said it came out of a working tv w/cracked screen of course. It worked fine for about 30min then shut off. I went and felt the heat sink on the strw6765 and it's blazing hot. And I touché the resistors above it and they are hot but not burning hot. And I touched the other two big heat sinks with mosfets on them an they are warm but not burning. I do not understand what the problem with this is. Why is it running so hot. And I'm sure that's why it shut down.

[dkneyle]

Re: New problem 42hl196

As a suggestion, I'd just check the various diodes that form part of the circuitry around that regulating device. You might have to lift one leg to accurately check. Bud is far more knowledgeable than me, but often these diodes perform a 'snubbing' function to prevent high frequency oscillations and the like, and if the diode has failed then the device can overheat although will initially function.

[audiofreak19]

Re: New problem 42hl196

That makes sense. Good call my friend. I will check that.