Z50PJ240 Powers on then back off clicks but no picture

[tom66]

Re: Z50PJ240 Powers on then back off clicks but no picture

Can you retry with all disconnected, except leave the resistors connected? If it still goes out, then it would appear to be a power board fault.

[soog35]

Re: Z50PJ240 Powers on then back off clicks but no picture

I tested it again with the cable unplugged, same results.
I have a few question.
1. Should i just replace the complete board?
2. If i do, some boards I've seen with my part number have 2 or 3 of those white resistors in the right hand corner. Mine has 3, does it matter?
3. Testing all the diodes on the board seem to be all open except for the one I replaced (D304) and one other one. Is that normal or are they all bad?
4. The Q802 transistor on the center heat sink, right above the IC301 voltage reg is where it was popping and a spark when it first clicks on. Could that be the problem?

[soog35]

Re: Z50PJ240 Powers on then back off clicks but no picture

pic

[tom66]

Re: Z50PJ240 Powers on then back off clicks but no picture

I don't know much about repairing these, unfortunately.

[tw2005]

Re: Z50PJ240 Powers on then back off clicks but no picture

D304 is short on mine, I think this is one of those special diodes that measure like this . TVS ?? Tom will know.

[tom66]

Re: Z50PJ240 Powers on then back off clicks but no picture

A diode will -never- read shorted if it is working.

[tw2005]

Re: Z50PJ240 Powers on then back off clicks but no picture

This power supply of mine is good, I've struck this before on another power board thinking it was bad. Can't read the part number, schematic would be handy.

See if I can find some info.

[tw2005]

Re: Z50PJ240 Powers on then back off clicks but no picture

Ok, you got me. Flipped the board over and found the answer. That one sits across 0.26ohm resistor so you'd have to remove it to find out. My leads are about 0.3, reads between 0.5-0.6 on my old fluke.

[soog35]

Re: Z50PJ240 Powers on then back off clicks but no picture

D304 is the diode that I already replaced. So you have to take them out to check them?

[soog35]

Re: Z50PJ240 Powers on then back off clicks but no picture

I think I'm just going to replace the board. Just need to confirm my answer in my no. 2 question. My board has 3 white resisters, can I replace it with one that has 2?

[tw2005]

Re: Z50PJ240 Powers on then back off clicks but no picture

I think I'm just going to replace the board. Just need to confirm my answer in my no. 2 question. My board has 3 white resisters, can I replace it with one that has 2?

I'm going to say yes. Your PSU part number and mine are the same. Mine has 2 resistors. PCB # mine is rev 12 (/12) yours is #11(/11) but being the same PSU part # it's doing the same job.

I'll jump on SJ and see if they sub but it would be ok I expect.

[tw2005]

Re: Z50PJ240 Powers on then back off clicks but no picture

SJ site just crashed. what's a PSU going to cost?

[soog35]

Re: Z50PJ240 Powers on then back off clicks but no picture

$83 to $140 most places are out of stock though. SJ is out of stock. Found one on ebay that has 2 resistors. it says it fits my model # but wanted to check with you guys to make sure.

[tw2005]

Re: Z50PJ240 Powers on then back off clicks but no picture

The part number comes up on SJ but just one version, yours with the 3 resistors. where are you getting the replacement from?

Mine has three boxes for model ID, LGIT PSPI-L912A AND IS RATED 100-240V AC INPUT, 50/60HZ, 5AMP 360W PDP MAX,17V 1A, 5.1V 3A, STDBY5V 1A, VS 197-207 1.6A, VA 60V 2A, 2010.6.14 REV 1.4

[soog35]

Re: Z50PJ240 Powers on then back off clicks but no picture

http://www.ebay.com/itm/300999241883

[soog35]

Re: Z50PJ240 Powers on then back off clicks but no picture

If you scroll down it says works with the following models. I have Z50PJ240UB
Do you think it will work?

[tw2005]

Re: Z50PJ240 Powers on then back off clicks but no picture

Same as mine, I can't remember but did it ever power up and stay on with both sustains isolated?

[tw2005]

Re: Z50PJ240 Powers on then back off clicks but no picture

If you scroll down it says works with the following models. I have Z50PJ240UB
Do you think it will work?

I have no doubt it will work for this TV, but will this fix all your troubles? that i can't answer

[soog35]

Re: Z50PJ240 Powers on then back off clicks but no picture

So is still possible that it could be in the sustain boards or buffer boards?

[tw2005]

Re: Z50PJ240 Powers on then back off clicks but no picture

well, I thought I read at some point the power stayed up and you had voltages to check?

Did this happen and did you take the opportunity to check if all voltages were present?

If the voltages were up, the control board was on and normal, jumpered for the test patterns but no image, I have to wonder.

I'd like to see if you can check out the sustains and buffers for any shorts. Check the resistance at the power connections on the Ysus and zsus. At least if you can post those up i can at grab mine and see if there is any wild differences.

It may be completely a waste of time and not the fault. I just think checking these out is not a bad idea because i can give you a good indication from my end of these boards I have which I know the TV powered up fully with both sustains firing.