Westinghouse WD55UDR101 4k LED TV Control Board Failure

[mmartell]

Well it looks like it to me except it's not a plasma so there is no control board

This has a combined Main/PS board and the tcon appears housed on the panel boards. I had just mounted this tv 24 hours earlier and was watching it when it shut off and wouldn't turn back on. Red standby and that's it.

Took it down and took the back off. After measuring some voltages the set finally turned on as shown in the first pic. Sometimes it displays the logo and other times blank screen but either way within 30 seconds it reboots itself.

The CSOT ic on the panel driver board/tcon gets real hot but unplugging the tcon cable doesn't change the reboot cycle.

So best guess on Main/PS (processor, ram, eeprom) or tcon failure possibly the CSOT whatever that may be ?

[mmartell]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Does this PS have a PFC booster ? The main caps are 400v but I only measure 160v in standby and when the tv comes on displaying the logo as above in first pic.

[mmartell]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Anyone have some insight or something to test ?

Basically I'd like to be able to identify the source of the problem, meaning I'll buy another main if it's defective or trash it if the panel is bad or attempt repair on the tcon if necessary.

[mmartell]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Has nobody seen an image like that in post one ? It's supposed to be solid black except for the logo.

[dick_barton]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Does this PS have a PFC booster ? The main caps are 400v but I only measure 160v in standby and when the tv comes on displaying the logo as above in first pic.

Without a schematic it would appear that if it has been fitted with 400V capacitors then I would have thought there would be a PFC supply.

[mmartell]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Right? It's not like manufacturers to put more expensive components in where not needed.

[Kilroy2k1]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Any change if you disconnect the backlights?

[mmartell]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

I think I can answer my own question about that. The power supply was likely designed to operate at 220v input as well as 110v so the mains rectified could be as high as 340v hence the 400v caps.

[mmartell]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Any change if you disconnect the backlights?

I will try that later. There doesn't seem to be a problem at all with the backlights though.

[mmartell]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Any change if you disconnect the backlights?

No change. I can see the logo but it's harder to see the artifacts but I have to presume they're there. They are definitely still there If I disconnect one or the other string at a time.

[diif]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Can I see the mainboard, has it got two processors ?

[mmartell]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

Can I see the mainboard, has it got two processors ?

One processor. Link courtesy of Shopjimmy

hxxps://www.shopjimmy.com/element-e1...-1094892288752

Change the "xx" to "tt"

[mmartell]

Re: Westinghouse WD55UDR101 4k LED TV Control Board Failure

This was resolved with a replacement main/ps combo board. Sound is back and working as well.

Interesting thing is the board came with a lvds cable much shorter than the one on my tv perhaps indicating this came from a tv with a discrete tcon board. Obviously the two are compatible if not the same.

It now boots with the RCA logo/screensplash but the menus are identical in look if not in content. The mismatch is of little consequence to me.