XVT3D554SV - Blinking Amber / White - PS Damage

[jason123]

Hi folks
Picked up this TV that had cycling Amber / White. Sent the board to Nick's TVs for repair.. after 4 attempts, I got the main board back with Proof of operation video.

It's doing exactly the same thing in my set. Amber / White flashing - then white, then repeat (Ethernet port shows activity now) I don't get any picture, backlight, or any other sign of life

All fuses on Main, and Tcon are ok. 12V is not coming on - and I can't really tell if the Main is issuing the ON signal - However in the process of removing the PS card (I was going to solder wires to force set on), I noticed a black charring around R38 and some on the leads of Q10 (See photos) - might explain why the 12V is not coming on.

Any thoughts on how to repair this? Anyone with a schematic that can help me troubleshoot this board? Replacing the Transistor would fix it? I don't know the value of the R38, but it's reading 635 kOhm
Thanks

[R_J]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Replacing Q10 will not fix the problem, you will also need ic8, R40,D13. also R38 is in the gate circuit it could be around 10~30Ω Also R39 (could be a 1k)
I suspect R45 is open also
Remove the baord and inspect the parts on the other side where ic8 is located.
There may also be more wrong with this board.
This was likely your problem all along not the main board

[MIGUELMURILLO79]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

amigo buenas tardes, Miguelmurillo te saluda podrías verificar la Eepron.

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Thanks R_J.. will check shortly. The main board has many shorted Caps (indicative of U41 Failure) - That's the first time I sent it. Got it back non-responsive - they ended up replacing main CPU (re-ball) - then last trip a capacitor that was fully shorted (they say).. so I think all 3 attempts were needed. Funny they claimed they tested it in a set each time prior to shipping. Only the last attempt was returned with proof of test video.
Thanks again

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Thanks Miguelmurillo79. I don't speak Spanish, but I gather you suspect it's the EPROM? the damage seems to be on the Power Supply board.
Thank you

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Replacing Q10 will not fix the problem, you will also need ic8, R40,D13. also R38 is in the gate circuit it could be around 10~30Ω Also R39 (could be a 1k)
I suspect R45 is open also
Remove the baord and inspect the parts on the other side where ic8 is located.
There may also be more wrong with this board.
This was likely your problem all along not the main board

R39, and R45 are open
R38 is cracked in half
R40 is open
D13 shorted
D18 shorted

IC8 is cracked (Can't make out part number)

Do you know of a repair kit? you seem to know exactly what's bad on this board.
Thanks

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

FAN7602 IC8??
Circuit looks different than the datasheet for that fairchild part. Trying to identify type of Diodes and resistor values.. any help is much appreciated.
Thank you

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Trying to identify some of the busted components and help is much appreciated.
R45: Band 1 Orange, Band 2: White, Band 3 (silver must be gray) and Band 4 is gold and band 5 is green: 39.8 Ohm 0.5% Tol?

R39: Brown, Black, Unknown, Orange and Gold: 10x kOhm 5%
R38: Yellow, Red, Unknown, Black, Gold: 42x Ohm 5%

Anyone had a board that can measure those for me? Also, on the back several diodes are shorted, any idea what type / spec diode these are?
Thanks

[budm]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

R45 is 0.39 Ohms, what do get on your Ohm meter?
The other 2 you can go to Shopjiimy to see if they have good clear pictures of your board.

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Hi budm
R39, and R45 are open
R38 is cracked in half
R40 is open
D13 shorted
D18 shorted
IC8 cracked in half

Tried shopjimmy... not much luck.. good picture, but difficult to make out colors

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Just bought a new PS board -
R45 measures 0.41 Ohm
R38 measures 46 Ohm
R39 362.9 Ohm
R40 5.1 Ohm

IC8 FAN7602

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

R38 measures 46.4 Ohm out of circuit
R39 .999k (1 KOhm) Ohm out of circuit

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Any additional tips or hints on how to go about repairing this board would be much appreciated. I replaced all the above component (guessed on the diodes, I used Schottky 60V 1A 1206 Package part) and no change - None of the rails other than the STBY is coming on.
Thanks

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

@budm & @R_J, any input?

[budm]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

So the TV is now working after installing the new power supply board, and now you want to fix the old power supply board, correct?

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Yes budm...

[budm]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Did you replace MOSFET Q10 too?
R39 is replaced with 1K, correct?
ZD4 tested OK?

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Yes, Q10 is replaced
R39 is 1k Ohm 1/4 watt
ZD4 is shorted (in and out of circuit) - Any idea what replacement I should get?
Thanks

[budm]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Trace out to see how that ZD4 is connected in the circuit.
https://www.shopjimmy.com/vizio-fsp2...nit-board.htm#
FAN7602
It is may be connected like as shown in the application circuit page 12.

[jason123]

Re: XVT3D554SV - Blinking Amber / White - PS Damage

Could this be right? It doesn't match app notes or datasheet connections. It's missing that Pin 1 of IC also goes to other parts on the board.