Z50PJ240 Powers on then back off clicks but no picture

[tw2005]

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

If Mohms then that's what i expect, Mine's about 3 meg vsus, 4meg Va and 5v is not steady but 1.5meg or so. They're not short, that's all I was concerned about.

So buffers not shorted, ysus power in not shorted, probably all you can establish apart from the zsus power in from the ysus.

All going well the PSU sorts it out, at least it won't be presented with a short cct when it comes on.

[soog35]

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

What should it be?

[soog35]

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

Mohms

[tw2005]

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

Help me here, put some units in like ohms or kohms (K) or Mohms(meg) or is it in diode mode?

If Vsus to gnd is 3.37 ohms on the ysus connector, it's stuffed or shorted?

[soog35]

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

testing the YSUS
grd to VS is 3.37
grd to VA and grd to 5v starts out about that but starts dropping
don't see 15 v
What is yours?

[soog35]

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

Checked the diode in diode mode and the resistor in ohms

[tw2005]

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

What should that diode read?

In diode mode could be o.5-0.7 . Which one are you probing and I'll tell you mine.

[tw2005]

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

visually it looks fine but I get 00.7 on that resistor.

Then it should be the same across the diode then D304, they're in parallel to each other. Where did 266 come from then.

[soog35]

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

What should that diode read?

[soog35]

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

visually it looks fine but I get 00.7 on that resistor.

[tw2005]

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

Since I won't get new PSU til Friday I went ahead and did this Control board test from the training manual, since the LED never stays on. Looks like the control board is good. Going to check the buffer board for shorts. Was a little unsure how to do that until i found video on YouTube. Turns out its Tom, glad to say you have another subscriber.

TW you also said to check Y-SUS and Z-SUS for resistance at the connections. Where do I put the leads? It has a lot of things to check in those manuals, but its a little confusing to me.

Just looking for obvious dead shorts or very low resistance. Just test between gnd and VS,Va & 15V. Other than maybe also using diode mode and probing the transistor legs for short and diodes for short that are mounted on those heatsinks.

Pick a transistor leg and probe the other 2, then move to next leg and repeat until they are all tested. EG 1-2,1-3,2-3

The 3 pin diodes generally the outer pins are tied together so will show short. center to either outer should test like a diode not shorted.

Do the Zsus and use the manuals for pinouts.

[tw2005]

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

Brentsky my D304 is 266.3 and the 3 white resistors were good, didn't have to replace them. I'm hoping the power board is my problem from the test I did.

Any evidence that large resistor R305 is burnt or tracks blown off underneath? I can't see how you can get 266ohms because of the 0.26 ohm resistor that sits across this diode.

[soog35]

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

Since I won't get new PSU til Friday I went ahead and did this Control board test from the training manual, since the LED never stays on. Looks like the control board is good. Going to check the buffer board for shorts. Was a little unsure how to do that until i found video on YouTube. Turns out its Tom, glad to say you have another subscriber.

TW you also said to check Y-SUS and Z-SUS for resistance at the connections. Where do I put the leads? It has a lot of things to check in those manuals, but its a little confusing to me.

[soog35]

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

Brentsky my D304 is 266.3 and the 3 white resistors were good, didn't have to replace them. I'm hoping the power board is my problem from the test I did.

[Brentsky]

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

They sell rebuild kits for those on ebay for around $17 it's 2-3 ceramic resistors (depends on board) + 1 fuse + 1 diode (d304) however don't get fooled by D304 not showing any resistance as it didn't show any resistance on either my old board b4 or after rebuild kit or the brand new one I ordered straight from Sears which was a factory direct part. Check the ceramic resistors (Tall white ones) at the top corner of the board. it is a common failure however according to Tom66 it is a less common failure on the model containing (3x) 5w 10ohm than it is on the one containing (2x 22ohm) on those ceramic resistors. but test them with a multimeter and see cause they do still fail on the model with 3.. they are very simple to replace and you may be able to get your old PSU working again to have as a spare.

[Brentsky]

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

Hey TW thx for the info. I must have jumped the wrong link or something cause it was showing $122 and 0 in stock on the ysus but that wasn't the green choice. I pulled all the buffer boards out and not a single spot that even looks close to like anything would have happened to them . I guess for now I'm gonna wait on the replacement Ysus board and am also gonna order a ysus/zsus and buffer board set from your link. It's worth the $100 to get this going again. I had previously checked the zsus board and saw no signs of any damage to that either however we all know not all problems are easily visible. I will certainly post back once I find the culprit.

[tw2005]

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

D304 reads 0 on both of my board that tested good including one brand new from Sears Parts..

As I had stated if I disconnect the lead going from the ysus board to the power supply (The Large Connector and thick wires) and power it on then it would power on without clicking back off so I had ordered a new Ysus board. I placed the new ysus board in and the tv fired up but the screen was messed up colors wise with some ghosting red blue colors as well as not showing all of the menu but was gradually scanning across and showing more until after about 1 minute I hear a pop and that ysus board was dead. I believe the part was DOA from the get go but I will be pulling all of the bottom buffers out tomorrow to check for flaws to make certain nothing is shorting out there. I'll keep you posted. Also soog if there's anything I can do to help let me know but try running it with just the 1 wire disconnected and everything else connected to see if it's your ysus board or not. if it is let me know and I will msg you a link to a place to get the part at a reasonable rate because nothing including TW's link has them in stock. I spent hours searching but saved about $30-$40 compared to ebay prices which were around $90+ but note that if it turns out to be teh ysus board it's possible a buffer board took it out.

Check the links closer

Green Choice EBR63039801 Ysus Board ( equivalent) 18 available $30
Green Choice EBR63551601 Ydrvtp Board Assy $22 over 50 available
Green Choice EBR63551701 Ydrvbt Board $20 over 50 available
Green Choice EBR63040301 Zsus Pcb $27 over 50 available

messed up picture sounds like shorting buffers and probably what blew the ysus, bad zsus also possible.

[Brentsky]

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?

D304 reads 0 on both of my board that tested good including one brand new from Sears Parts..

As I had stated if I disconnect the lead going from the ysus board to the power supply (The Large Connector and thick wires) and power it on then it would power on without clicking back off so I had ordered a new Ysus board. I placed the new ysus board in and the tv fired up but the screen was messed up colors wise with some ghosting red blue colors as well as not showing all of the menu but was gradually scanning across and showing more until after about 1 minute I hear a pop and that ysus board was dead. I believe the part was DOA from the get go but I will be pulling all of the bottom buffers out tomorrow to check for flaws to make certain nothing is shorting out there. I'll keep you posted. Also soog if there's anything I can do to help let me know but try running it with just the 1 wire disconnected and everything else connected to see if it's your ysus board or not. if it is let me know and I will msg you a link to a place to get the part at a reasonable rate because nothing including TW's link has them in stock. I spent hours searching but saved about $30-$40 compared to ebay prices which were around $90+ but note that if it turns out to be teh ysus board it's possible a buffer board took it out.

[soog35]

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

I did see those already. Didn't have a lot of confidence it those. I ordered the one on ebay that said factory original.

[soog35]

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

Ok thanks!!