Vizio SV471XVT No Standby, Dead Set

[fharris1977]

Hello. I got a vizio i'm trying to repair and I'm pretty sure it's the power supply because of no standby. The fuse is open and i was wondering if I could replace it with a fuse with the same specs but different size. I ordered 10 mm instead of 20 mm. Also, if anyone has repaired this board before, I'd appreciate their help, because the board costs about 100 bucks. Thanks.

[budm]

Re: Vizio SV471XVT No Standby, Dead Set

We cannot tell what you have exactly. Where are the pictures?
There are more than one version of this TV.
https://www.badcaps.net/forum/showthread.php?t=39740

[dick_barton]

Re: Vizio SV471XVT No Standby, Dead Set

Hello. I got a vizio i'm trying to repair and I'm pretty sure it's the power supply because of no standby. The fuse is open and i was wondering if I could replace it with a fuse with the same specs but different size. I ordered 10 mm instead of 20 mm. Also, if anyone has repaired this board before, I'd appreciate their help, because the board costs about 100 bucks. Thanks.

If the fuse has blown I would investigate why and not just replace it. If there's a fault then it would just blow again and could cause more damage.
Replace the fuse with an identical fuse, length and current rating and don't bodge it.

[fharris1977]

Re: Vizio SV471XVT No Standby, Dead Set

I think the fuse actually blew when I tested the bridge rectifier for the 160 volts dc. I got 120 volts ac input when I tested it, but heard a spark when I tried to test the 160 volts output. But I have to order the correct size fuse due to limited parts in mississippi. Here are pics of the power supply and the wrong sized fuse but same specs.

[dick_barton]

Re: Vizio SV471XVT No Standby, Dead Set

I think the fuse actually blew when I tested the bridge rectifier for the 160 volts dc. I got 120 volts ac input when I tested it, but heard a spark when I tried to test the 160 volts output. But I have to order the correct size fuse due to limited parts in mississippi. Here are pics of the power supply and the wrong sized fuse but same specs.

So it's not a clip in fuse as I thought so you should be OK to use as a replacement. I would be tempted to add some insulated sleeving on the exposed leads and then solder it in.

How about some photo's of the full power supply

[vinceroger69]

Re: Vizio SV471XVT No Standby, Dead Set

i would also re test the bridge rectifier just incase thats gone short circuit before you replace the fuse

[budm]

Re: Vizio SV471XVT No Standby, Dead Set

So that smaller body fuse has the same Voltage rating as the original fuse?

[fharris1977]

Re: Vizio SV471XVT No Standby, Dead Set

So that smaller body fuse has the same Voltage rating as the original fuse?

Yep. It's 6.3 amp 250v

[fharris1977]

Re: Vizio SV471XVT No Standby, Dead Set

Here are more pics of the power supply and the inside and outside of the tv itself.

[budm]

Re: Vizio SV471XVT No Standby, Dead Set

Can you please provide the straight shot pictures of the bottom side of the board.
Too bad the large heatsink cannot be easily removed to see the parts under the heatsink.
I would check the resistance between the two outer pins of the bridge to see if it shows low resistance (bad) reading that can cause the fuse to blow or not, also the power devices mounted on the heatstink should also be checked for low resistance (bad).

http://www.shopjimmy.com/vizio-0500-...upply-unit.htm
Vizio 0500-0407-0800 (DPS-303AP A) Power Supply for SV471XVT

[Ian Paul]

Re: Vizio SV471XVT No Standby, Dead Set

Is your replacement Time-lag fuse, denoted with a T?

[fharris1977]

Re: Vizio SV471XVT No Standby, Dead Set

Is your replacement Time-lag fuse, denoted with a T?

This is how the fuse was listed on ebay I bought. 6.3A 250v Fuses CERAMIC, Fast Blow, F6.3A, 6.3 amp 6.3A, 3.6X10mm. Does it sound like the right one. I didn't know whether to get the fast blow or slow blow ones.

[budm]

Re: Vizio SV471XVT No Standby, Dead Set

If you at the label for the fuse rating as printed on the circuit board then you can tell if it is Time delays or Fast-blo.
Does it show as T6.3 250V, T= Time-Delayed which is more likely yo be used on your board.
That little fuse is blocking the print so I cannot see what is printed on the board.

[fharris1977]

Re: Vizio SV471XVT No Standby, Dead Set

Yeah its a T. I got the wrong one. Feel kinda stupid now.

[Ian Paul]

Re: Vizio SV471XVT No Standby, Dead Set

This fuse should be available from Mouser/Digikey: BK-S505H-V-6.3-R

[fharris1977]

Re: Vizio SV471XVT No Standby, Dead Set

Can you please provide the straight shot pictures of the bottom side of the board.
Too bad the large heatsink cannot be easily removed to see the parts under the heatsink.
I would check the resistance between the two outer pins of the bridge to see if it shows low resistance (bad) reading that can cause the fuse to blow or not, also the power devices mounted on the heatstink should also be checked for low resistance (bad).

http://www.shopjimmy.com/vizio-0500-...upply-unit.htm
Vizio 0500-0407-0800 (DPS-303AP A) Power Supply for SV471XVT

I hate to sound stupid but when checking these components, is it best to desolder them and take them out of circuit for best results. I know capacitors do for sure, but what about mosfets and rectifiers and diodes, etc.

[budm]

Re: Vizio SV471XVT No Standby, Dead Set

You can do resistance test to look for shorts or low resistance on the those components I suggested, and when the reading looks suspicious then you remove it from the board and test it again off the board.