Westinghouse LTV-32W6 intermittent fault

[rubicondsrv]

Customer requested that I service this unit due to an intermitent failure to turn on properly.

Unit will turn on, and then after a few minutes the screen turns off, but blue power light stays on.

Sometimes the screen fails to turn on at all, but blue light still comes on.

Inspected power supply, no bulging or leaking caps, all rubycons.

I suspect a fault in the logic board, and am planing on updating the firmware to see if that resolves the issue.

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

no firmware was avalible, is it possible that this is an inverter issue?
I want to be sure before ordering parts

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

one of the inverters is running warmer than the others.

[mockingbird]

Re: Westinghouse LTV-32W6 intermittent fault

Can we have a pic of these "Rubycons" on the PCB? I have an inklink that they are fake.

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

ok ill get pics when i can......just ran it with the inverters disconnected and it just quit again.

I guess that rules out inverters

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

pics of caps

[mockingbird]

Re: Westinghouse LTV-32W6 intermittent fault

They look ok. The bunge (Underneath the cap), well at least the Nichicon which is sideway soldered so you can see it, what does that look like?

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

looks fine, no leaks or bulging

also when the unit cuts out, the blue power light stays on, and the tv must be unpluged and reconected before ot will start again

[mockingbird]

Re: Westinghouse LTV-32W6 intermittent fault

But what does it look like... the underside of the nichicon.

Do the bunges look like this:


Or like this:

[PlainBill]

Re: Westinghouse LTV-32W6 intermittent fault

looks fine, no leaks or bulging

also when the unit cuts out, the blue power light stays on, and the tv must be unpluged and reconected before ot will start again

One possible cause of those symptoms is a failing voltage regulator on the main board. Check the output voltages.

PlainBill

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

where do i check the voltages, and what should they read?

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

main board

[PlainBill]

Re: Westinghouse LTV-32W6 intermittent fault

main board

Good move; I was going to comment that it helps to have a picture. I've circled them. For each one, identify the part number. Select a convenient ground point, and measure the voltage on each pin. Post the part number and the voltages you measured. Repeat after the TV fails.

PlainBill

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

well, so far i havent been able to get readings off it, but got new symptoms...

it now wolnt recognise hdmi signals from my computer, claiming invalid format before shutting off.

honestly, im not interested in reparing the main board but just need to verify that it is the fault so i can replace it.

it also wolnt turn off once it gose into fail mode, i have to unplug it to turn it off.

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

ok, i have voltages amd part numbers for the circled parts, but no voltages for when the unit is failed, because now it refuses to go out.



7805bd2t
2.03,6.54

1084-33pm
-3, 1.9

LD1085
1.88, -1.68


fr9024n
7.68,9.27

4.67, 9.27

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

and it now is working perfectly......

but i did nothing except test the voltages

It even turns off and back on without trouble right now...

I guess i might need to just replace the main board and hope it is fixed, though Id hate to do that without knowing that it would stay fixed.

[mockingbird]

Re: Westinghouse LTV-32W6 intermittent fault

That means your caps are the problem I reckon.

[PlainBill]

Re: Westinghouse LTV-32W6 intermittent fault

That means your caps are the problem I reckon.

Ahh - no. Far more likely that the problem is a lead-free solder joint; the flexing of the board as the testing was done caused two points to make contact. Now they are waiting until the back is on and the TV is in the family room before parting company again.

PlainBill

[rubicondsrv]

Re: Westinghouse LTV-32W6 intermittent fault

Ahh - no. Far more likely that the problem is a lead-free solder joint; the flexing of the board as the testing was done caused two points to make contact. Now they are waiting until the back is on and the TV is in the family room before parting company again.

PlainBill

that makes sense, when I was checking voltages and it refused to fail the tv was laying flat. when it failed, it was usualy upright.

Unfortunately I dont have the equiptment to reflow the bga and surface mount parts properly, so i will have to replace the main board.

[PlainBill]

Re: Westinghouse LTV-32W6 intermittent fault

that makes sense, when I was checking voltages and it refused to fail the tv was laying flat. when it failed, it was usualy upright.

Unfortunately I dont have the equiptment to reflow the bga and surface mount parts properly, so i will have to replace the main board.

That seems more practical than mounting it on the ceiling.

PlainBill