Westinghouse VR-4625 wont turn on

[jesselyons2002]

Re: Westinghouse VR-4625 wont turn on

So whats the next move ???

[jesselyons2002]

Re: Westinghouse VR-4625 wont turn on

Can someone show me how to turn on a power supply board so I can make sure its the power supply thats bad.

[Agent24]

Re: Westinghouse VR-4625 wont turn on

The power board usually gets a signal from the main board to tell it to turn on (or rather, come out of standby)

I'm guessing it would be pin 'STB' on the biggest white connector, and since it has 5v on it, it is probably supposed to be pulled low to turn the supply on since everything else looks like supply rails.

To verify, can you post a better photo of the underside of the board around that connector?

[jesselyons2002]

Re: Westinghouse VR-4625 wont turn on

Here a pic from shop jimmy

[Agent24]

Re: Westinghouse VR-4625 wont turn on

I'll try to help how I can... See the attached picture for the STB pin that I'm talking about.

Looks like you would probably ground STB which would draw current from Q401 (probably a PNP transistor) which looks like it controls the PC2 opto-isolator which sends a power-on signal through some other circuits to the main PWM controller.

To confirm, try with the thing hooked up and see if that STB line goes LOW when you press power button. If not the logic board may be the problem.

If you can give part numbers for the two components (Q401) and the IC next to it, that would be helpful in determining with more certainty how that pin works.

Also the PWM controller IC303 part number might help with troubleshooting.

[budm]

Re: Westinghouse VR-4625 wont turn on

Have not seen your post for awhile, those resistance reading I request looks OK, it does not explain why you only have 18VDC on the main cap. We need to get 160~170VDC on the main cap first.

[bwilliams60]

Re: Westinghouse VR-4625 wont turn on

Was there ever an end result to this post? Does anybody have a schematic diagram or service manual for this TV set?

[budm]

Re: Westinghouse VR-4625 wont turn on

The OP never comes back, and we still need to find out the actual voltage on the main filter cap.

[pbones]

Re: Westinghouse VR-4625 wont turn on

I have been working on my vr-4625 for weeks posting in a different forum for help. I ran across this one and thought I would offer up what little I know.
Background. My TV turns on stays on for 5-10 min then the screen goes black the blue on light stays blue and I have to power the TV on and off, although following the power cycle thentv only stays on for 10-20 seconds then black again. Let the TV set for 30 min and it works for 5-10 min again.
To help with testing the power supply. Disconnect all the cables from the power supply. Connect STBY TO 5VSB using a 32-50 ohm resistor. This should turn on Turn on the power supply...use a DVM to measure then outputs 12 v and 24 v. This will only test the function of the 5 v tap. After 15 min the power supply will sense no current in the12 or 24 v outputs and shut those outputs down. This would be normal. Now to test the other outputs use a resistor or load rated above th minimum current and load down the 12&24v outputs. Example 24 v min is 0.5 amps ( 24v/0.5amps=48 ohms at 12 watts) please don't try to use a small resistor rated less than 12 watts.Do the same for the 12 v output.plug in the supply and the outputs should be working. I timed mine as I used and led in the circuit to verify when the power supply shut off. I am not done fixing mine but I known for a fact the power supply is faulty. Hope this helps. Please be carefull . The main cap should hold 166 vdc. Also if the reddish fuse marked 5 amps 250 v near the ac connector on the power supply then try testing the bridge rectifier to the left of the red fuse. Two middle pins 120 vac two outer pins 160-170 CDC.

[pbones]

Re: Westinghouse VR-4625 wont turn on

The 32-50 ohm resistor needs to be at least 1/2 watt not 1/4 watt.

[pbones]

Re: Westinghouse VR-4625 wont turn on

The 32-50 ohm resistor needs to be at least 1/2 watt not 1/4 watt. Also the minimum load requirement for the 12 v output is 0.3 amps.

[pbones]

Re: Westinghouse VR-4625 wont turn on

I'm sorry I only read then last page of the thread you guys are working on the high side... while I have problems on then low side. It sounds like then issue is on the lower left side near then inductor coils. What's odd is the only items should be the inductors a few small blue capacitors then the bridge rectifier. There's not a lot of items between the ac input and the rectifier ac leads. Good luck:-)