A question about a blown fuse on Vizio main board.

[johnboy1313]

I picked up a Vizio VX32L last week that has turned into a pain in my backside. I narrowed the problem down to a bad voltage regulator on the main board, but screwed up trying to replace it. I found a website that cross referenced the board number with two other boards. I found one of the cross referenced boards on eBay for a price that I could live with. The board came in today and I put it in the TV. I get power for 3 seconds and then nothing. I went through the voltage regulators and they all seem to be good, so I turned to the fuses. In the picture below, the fuse on the right (the vertical one) shows to be open. Figuring I am done with this set, I jumpered the fuse and hit the power button. The thing came to life and has a good picture and good sound. I immediately shut it down at that point and removed the jumper wire.

With that said, will running jumpers from the ends of the bad fuse to the ends of the good fuse on the bad panel be test enough to tell me if I can just replace the fuse?

[tom66]

Re: A question about a blown fuse on Vizio main board.

It is a common problem:
https://www.youtube.com/watch?v=qC9FEZ78-qM

[johnboy1313]

Re: A question about a blown fuse on Vizio main board.

So, I went ahead and ran some wires to the other fuse. It seems to be fine. Am I wrong to assume that the fuse should have blown right away if it was going to?







I'm not the best with surface mount components and there's not a lot of room to get in there, so I'm thinking one of three options.

1) Remove both fuses from both panels and fix it correctly, once and for all. This one is the most permanent fix but the easiest for me to screw up.
2) Remove the good fuse and solder it directly on top of the bad one. This one is pretty permanent if it works but kinda hokey and still kinda easy for me to screw up.
3) Find out the V and A rating of that fuse and replace it with an inline fuse holder mounted to a separate board with jumper wires soldered to the ends of each. Not very permanent, pretty hokey, but super easy.

I think I know the answer, just looking for input.

Oh, I guess there's another...
4) Send this one back to the seller DOA and get a refund.

[johnboy1313]

Re: A question about a blown fuse on Vizio main board.

Thanks for that video. Is that you in the video or have you just come across these? Thanks again.

[budm]

Re: A question about a blown fuse on Vizio main board.

Put you rmeter in DC AMP mode and put the two probes on each end of the fuse to see how much current the board is drawing, the fuse is 3A, if it is, then it should show around 2A on the meter.
If the current reading is OK, you can just stack the new fuse on top of the old one and solder it in at both ends.
The rating of the fuse is printed on top of the fuse.

[johnboy1313]

Re: A question about a blown fuse on Vizio main board.

Thanks

[johnboy1313]

Re: A question about a blown fuse on Vizio main board.

With the red lead swapped to the 10A spot on the meter and the switch set to the 10A setting, I get a reading of 0.75A through the fuse. I went ahead and stacked the fuses. The unit is working fine now. Thanks again, I owe you a couple now.

[budm]

Re: A question about a blown fuse on Vizio main board.

That is low, last week I worked on Vizio VO370M with blown fuse on the board similar to yours, the 3A was blown, I measured the current draw, it was at 3A which could not be right, you usually use the fuse rating at 25% ~125% higher or more than the steady state and the correct type depends on the in-rush current. I touch the heat sink of the processor, it was too hot to touch, and that unit was still in standby mode.
You are getting good at fixing the TVs now.

[johnboy1313]

Re: A question about a blown fuse on Vizio main board.

It started out at .33A and when the backlights popped on, it jumped to .65A then slowly climbed to .75A.

[budm]

Re: A question about a blown fuse on Vizio main board.

It is OK, what was the number as printed on the fuse anyway? xA?

[johnboy1313]

Re: A question about a blown fuse on Vizio main board.

3a

[tom66]

Re: A question about a blown fuse on Vizio main board.

Thanks for that video. Is that you in the video or have you just come across these? Thanks again.

Do I have an American accent?
No, it's not me. I speak the Queen's English. :P

[johnboy1313]

Re: A question about a blown fuse on Vizio main board.

Ahh, jolly good then mate!

[tom66]

Re: A question about a blown fuse on Vizio main board.

Right-ol! Splendid day, eh? Spiffing time yourself!