Westinghouse EW46T4LZ

[Malachi]

I picked this tv up today. Only getting red power led.
I measured the voltage between the two big caps and it reads 167vdc, either with the mainboard connected or not. I believe from set experience it should read about 400v correct?
None of the other connectors are labeled and with my limited experience I am not sure what to test next.

[Malachi]

Re: Westinghouse EW46T4LZ

Here is a better picture, curtesy of shopjimmy.

[dick_barton]

Re: Westinghouse EW46T4LZ

Does Con3 have any legends on the rear of the board?

[Malachi]

Re: Westinghouse EW46T4LZ

I never thought to look on the back. I'll take it out now.
Yes it does. What a pain in the arse to put it as your Brits do.

[dick_barton]

Re: Westinghouse EW46T4LZ

OK so you can now check for standby voltage and jumper Power On to check the rest of the supplies.

[Malachi]

Re: Westinghouse EW46T4LZ

I think I will buy a known working board from ebay.
It looks like someone has already tried to fix this one. The soldering doesnt look like a factory job, looks like mine. lol

If you think those look like factory work, I may try to fix it.

[Electronic Handyman]

Re: Westinghouse EW46T4LZ

That board does look like someone has worked on it and part of that circuit looks like from your pic that it could be damaged or burnt.

[Malachi]

Re: Westinghouse EW46T4LZ

Got the working used board in today, although the box was pretty beat up and con3 was pretty bent.
I installed it. The front led goes from red to green, I get 5v on all the pins marked 5v, for 5VSB I about 4.1
On the 12V pins, I get nothing. Not sure if the board was damaged and I can't tell.
Why is 12v not present? What should I check?

[dick_barton]

Re: Westinghouse EW46T4LZ

Unplug the power board from the mainboard and see if you have your 5V and 12V. If not jumper (1K) between 5VSB and PS_ON and check again.
If that doesn't work some power supplies have PS_ON go low to switch the supplies on so the last test would be to jumper PS_ON to GND pin again use 1K resistor.
If you don't have the expected supplies then ship the board back.

[Malachi]

Re: Westinghouse EW46T4LZ

Even though 5vsb is only 4.1v?

I know I have 5V on the pins labeled 5.1V and nothing on the 12V pins with the mainboard disconnected.

The description of my problem now matches what shopjimmy lists for replacing the eeprom.

[dick_barton]

Re: Westinghouse EW46T4LZ

So you have 4.1V standby and 5V but no 12V. I would still jumper it and see if the 12V supply comes up

What is the voltage rating of the two long capacitors EC1 and EC2?

[Malachi]

Re: Westinghouse EW46T4LZ

Almost 400v now with this supply. With the older one about 160.
I will try jumping the 5VSB to ground in just a couple minutes.

[dick_barton]

Re: Westinghouse EW46T4LZ

So your PFC is working so if the 12V does not come up I would be suspecting a fault on the power board. Possible diode open circuit.

[Malachi]

Re: Westinghouse EW46T4LZ

Jumping ps-on to ground did nothing. When the mainboard is disconnected from the psu, ps-on has no voltage reading. Only with the mainboard connected does ps-on read 4.1v.

Sorry for the confusion. Since the level is on the bottom of the board, I'm having to look at the old board flipped over and I got confused.

To recap, with the front led on green and mainboard connected, I get 5.1v on the pins labeled 5.1v.
I get 5.1V on standby.
I get 4.1V on ps-on and nothing on 12V.

Only standby has 5.1V with the mainboard disconnected.

[Malachi]

Re: Westinghouse EW46T4LZ

Yes it was. Dick told me to.
Als jumping 5VSB to ground still didn't give me any reading on the 12v pins.

With the mainboard disconnected I also only get 166V between the two long caps.

[dick_barton]

Re: Westinghouse EW46T4LZ

The 4.1V supplied by the MB to P_ON is fine. It cerainly looks as though you have a problem on the 12V supply on the power supply.

[Malachi]

Re: Westinghouse EW46T4LZ

Unplug the power board from the mainboard and see if you have your 5V and 12V. If not jumper (1K) between 5VSB and PS_ON and check again.
If that doesn't work some power supplies have PS_ON go low to switch the supplies on so the last test would be to jumper PS_ON to GND pin again use 1K resistor.
If you don't have the expected supplies then ship the board back.

He did write it. Can't you read it?

[dick_barton]

Re: Westinghouse EW46T4LZ

hahah don't blame him i don't think he will write this to you... you bought PWB, go head to buy MB now...

Hello Diah,
Checks were being done with the mainboard disconnected from the power supply and using a 1K resistor so should not cause any problems?

[budm]

Re: Westinghouse EW46T4LZ

Yes it was. Dick told me to.
Als jumping 5VSB to ground still didn't give me any reading on the 12v pins.

With the mainboard disconnected I also only get 166V between the two long caps.

So you shorted the 5VSTBY power supply pin to GND?
I hope the 5VSTBY power supply is not damaged.
Never anything to anything without using the resistor in case it was done wrong.

[Malachi]

Re: Westinghouse EW46T4LZ

Yes bud it was with a resistor in place and mainboard always disconnected.