Vizio M502i-B1 Power Supply Issue

[R_J]

Re: Vizio M502i-B1 Power Supply Issue

On your original board the +12v was 11.6 and the +24 volts measured 19.7 volts, What do you measure on the replacement board for the +12v and the +24v?

[nomoresonys]

Re: Vizio M502i-B1 Power Supply Issue

Did you replace everything in the repair kit? maybe re-check your solder work. https://www.shopjimmy.com/vizio-adtv...r-m502i-b1.htm

[nomoresonys]

Re: Vizio M502i-B1 Power Supply Issue

Maybe check ALL the diodes and the solder joints of CN9101 connector and check all the solder joints on the board, maybe use a magnifying glass.

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

Thanks R_J and nomoresonys, I will check those things tomorrow and let you know.

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

R_J, the voltages for both boards are the same....11.6 volts and 19.7 volts. When holding the power button for 30 seconds to drain power on both boards, when plugged back in, the replacement board powers up but the original board does not.

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

nomoresonys, I did replace everything in the repair kit except the main power fuse. The original fuse checks ok. I checked solder joints also.

[nomoresonys]

Re: Vizio M502i-B1 Power Supply Issue

With the new powerboard in are you still getting that 1.1v low reading on the ps_on? I think I would be tempted to check every capacitor on that faulty board.

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

The 1.1 volt reading was only on the old board when it wouldn't power on. So, is there a possibility that the voltage regulator might be defective?

[R_J]

Re: Vizio M502i-B1 Power Supply Issue

What is the pin number on CN9101 that you measure 1.1 volts?

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

R_J, that would be pin #2 - on/off.

[R_J]

Re: Vizio M502i-B1 Power Supply Issue

Pin#2 has nothing to do with the operation of the power supply, it simply connets CN9101 pin#2 to CN9102 pin#12 and is the inverter on/off There are a couple mlcc caps on that line and an inline resistor, R9102, check that the resistor does'nt have bad solder connections

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

Thanks R_J. The solder joints look ok. What I don't understand is why would disconnecting the cable at the power supply from the main board, and reconnecting it cause the power to return? Could it be a resistor, cap, ic,
transistor causing this. Also after reconnecting the cable to the power supply, the standby light flashes twice and then it takes about 15 to 20 seconds to come on. Sorry for all this. But I do appreciate the help.

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

If nobody has anymore ideas, I might just give up on it. I was just trying to offset some of the cost of the replacement power supply board.

[nomoresonys]

Re: Vizio M502i-B1 Power Supply Issue

Maybe try heating the caps with a hairdryer, see if tv comes on or comes on any faster.

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

I actually replaced some of the caps but I will try that on the others. Thank you nomoresonys.

[R_J]

Re: Vizio M502i-B1 Power Supply Issue

Maybe if you uploaded some pictures of your power supply we might see something that is wrong.

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

I will do that. It will probably be tomorrow. Thanks R_J.

[rohit24]

Re: Vizio M502i-B1 Power Supply Issue

Well guys, I finally decided to replace the power supply and that fixed the TV. I still wish I could figure out what's wrong with the defective board so I could repair it and sell it to offset some of the cost of the replacement board. I've been looking for repair kit for this board but can't find one other than one on ebay and they won't sell to me for some reason. Does anybody know where I can get a repair kit for this board? Thanks for all the help and sorry for the long post.

Can you please share where did you buy the power supply from?

[JunkmanJimbo]

Re: Vizio M502i-B1 Power Supply Issue

Sure rohit24. I bought it from tv parts today.

[budm]

Re: Vizio M502i-B1 Power Supply Issue

https://www.tvpartstoday.com/ADTVD36...tvd3613xa7.htm