Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

[realdeelz]

Hey Gang,
newbie here with decent electronics base. Just to let you guys know that you are super...great forum here. Ok, I have done some reading regarding "no picture, no sound" condition with the vizio GV42L and concluded without doing any testing that I would replace the regulators as needed. So, I went ahead and purchased both fixed and adjustable regulators...now, here is my concern...most of the information I've read have shown U33, U7, U8, and U9 to be of fault 97% of the times with the aforementioned symptoms, but on my board show U33 to be 16 pin chip (P15C/32570E/Z0644), however, there is DU2 sitting in close proximity with SOT-223 case next to U33. What I would like to know is, what are the relevant numbers for my board?

[tom66]

Re: Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

Do you have a digital multimeter? You can test the regulators using one, then you will know which need to be replaced.

Vizio seem to have used several different boards with these models, so the faulty regulator could have a different reference.

[tibimakai]

Re: Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

on a 47" one I had only a suface mount fuse blown on the main board, I think it was F1. Did you try those if they are good?

[realdeelz]

Re: Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

Tom66, yes I do have multi-meter...but I was trying to avoid doing the preliminary test of the regulators due to the limited space I have where I have the tv laid out. I have taken out the main board and have it on my computer desk as I type away at the keyboard...tibimakai, I check fuse initially and it tested good. I dont mind using the shotgun approach ...by this I mean, replacing the relevant regulators...anyone out there with similar (3B) Board that can help me id the relevant Regulators for this board? Thanks guys.

[realdeelz]

Re: Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

who's got the schematics for this? Someone please point me to the schematic for this...

[tibimakai]

Re: Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

http://elektrotanya.com/?q=showresult

[realdeelz]

Re: Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

Thank you very much! I will revisit the project on the weekend...will keep you posted.

[david37g]

Re: Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

Just repaired a gv42l with 3642-0032-0150(3B) main board. I had no back light, it would power on but not off. There was 24 volts to the inverters but no back light. The mosfets on the inverter boards were grounded so there was no voltage out. Downloaded the service manual from http://elektrotanya.com/?q=showresult and went to the main board DCto DC trouble shooting guide. All voltages were good except U-5 Which had only 1.2 volts out instead of 1.8. I replaced it with another ACM1117a and I had a backlight.

[Silviyius]

Re: Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

Thank god this thread was so useful. Anyone know where I can get some voltage regulators?

[tom66]

Re: Troubleshooting GV42L HDTV Main Board #3642-0032-0150(3B)

Digi-Key is a good source. Type the part number in to find the part.