vizio e321vl no 12v

[kevin.st56]

Re: vizio e321vl no 12v

Couldnt find p_on or Q1, but measured all the mosphets that were labeled Q##, and all looked good.

[dick_barton]

Re: vizio e321vl no 12v

Couldnt find p_on or Q1, but measured all the mosphets that were labeled Q##, and all looked good.

Sorry PSON not P_On

[kevin.st56]

Re: vizio e321vl no 12v

A diagram would help. I dont see Q1 anywhere. Theres a Q14 near the main connector, and thats it.

[dick_barton]

Re: vizio e321vl no 12v

Clear sharp pictures of your board would have be extremely helpful however looking at the one that Budm posted, I've circled the 3 transistors/mosfets that could be checked for short circuit. See if you can trace the connection from the the Remote ON/OFF pin to one of those 3 devices.

[kevin.st56]

Re: vizio e321vl no 12v

Ah ok, thats underneath the power supply board. I thought we were still on the main board.
Ill check it when i have some downtime

[dick_barton]

Re: vizio e321vl no 12v

Sorry Kevin
Ignore my previous post. The low resistance is on the mainboard not the power supply board and I'm getting myself mixed up.
Its a clear photo of the underside of the main board at the connector to try and work out where the Remote On/Off connects to is what I'm after. That is the pin which is showing almost a short circuit, isn't it?

[kevin.st56]

Re: vizio e321vl no 12v

The pics budm posted are the top and underneath of the power supply board. Ones i posted are of just the top of the main board.
Attached is the underneath of the main board.
There are only 3 mosphets at the lower right corner (Q42, Q41, and Q18)

[dick_barton]

Re: vizio e321vl no 12v

I can't read the component numbers but it would be worth checking the 3 pin devices shown in the photo.

[kevin.st56]

Re: vizio e321vl no 12v

Finally got some time to check the tv.
In the first pic you showed 3 mosphets to check resistant on (Q250, Q251, Q203), Q250 and Q251 checked fine. Q203 however showed an openon 2 of the 3 legs.

On the second pic where you highlighted 6 mosphets on the top of the mainboard, those all show fine.

Edit: traced the traces from the remote on/off, and the open mosphet is what is on that circuit

[kevin.st56]

Re: vizio e321vl no 12v

just letting everyone in this old thread know that i fixed the tv by replacing the main control board.
although there were no noticable damage on the board, something somewhere was damaged, and i simply replaced it with a known working one from ebay.
thanks everyone who contributed to this thread.