Fuse blows immediately when I plug in power cord into my Vizio VW42LFHDTV10A TV Help!

[troydi40]

When I put a new fuse into the Power Supply Unit board in my Vizio Model:VW42LFHDTV10A TV, when I plug in the power cord, the fuse blows immediately. I measured the electricity coming out of the power cord (tried several power cords too) and it seems to be fine. Can anyone give me an idea where to look? The PSU board looks fine, but I know looks can be deceiving. Is it safe to say I need a new PSU board? or can anything else in the TV blow a fuse? Your help is very much appreciated!

[troydi40]

Re: Fuse blows immediately when I plug in power cord into my Vizio VW42LFHDTV10A TV H

Oh, I also get no lights, no picture, no power of any kind when this happens. The fuse blows to fast.

[mariushm]

Re: Fuse blows immediately when I plug in power cord into my Vizio VW42LFHDTV10A TV H

Follow the trace going from the fuse to the insides of the board and check each component touching that trace from the fuse with a multimeter. Set the meter on continuity and touch component leads with both probes to see if they're shorted (with power to the monitor off)
Measure it with the continuity function of your meter and see if the component is shorted. Check diodes to see if they conduct in both directions.

If you still can't determine the component with issues, see what voltage is supposed to come on that trace where the fuse blows, then get an adjustable power supply with current limit function, set the current limit to something low like 100-200mA and connect the power from the power supply to the fuse side with the trace... see what component that's on the trace is much hotter than the others and then remove the power and test that component.

[selldoor]

Re: Fuse blows immediately when I plug in power cord into my Vizio VW42LFHDTV10A TV H

Welcome to the forum-
We can help a lot more if you please post good clear pictures of the whole chassis, and then pictures of each board, front and back (in the same orientation) and close up of connectors, (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed

https://www.badcaps.net/forum/attach...7&d=1280167246

https://www.badcaps.net/forum/attach...6&d=1280167246

https://www.badcaps.net/forum/attach...4&d=1280167246

It will be useful if you can say a bit about yourself - skills tools etc.