HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

[zdsh07p9]

I have a HP PL4260N that a friend wanted me to repair, got it back from Coppell and adjusted VS and Va to 186 and 60 V, respectfully. Then adjusted the both the VSC and -Vy accordingly as well. I know I dont have set_up and Set_down adjusted correctly but ive noticed that all different settings of those two options do not get rid of these red dots. Please help, thank you

[tom66]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

If you friend owned the TV before it is faulty, then he would have noticed these dots, very common on LG panels.

Capkid offers a $22.50 service (+your postage cost) to fix this:
https://www.badcaps.net/forum/showthread.php?t=29263

which is pretty reasonable given the programming jig from LG is around $150!

[zdsh07p9]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

So this is a fix for this tv if there are only red dots? that are constant even if the pots are adjusted? I can adjust them so that they almost go away but not fully, still a good amount of specks on the screen, I dont think they flash either

[tom66]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

They are completely static or flashing randomly? They can flash in places where there was a previous image and some pixels may flash more than others.

[cinemax111]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

Capkid offers a $22.50 service (+your postage cost) to fix this:
https://www.badcaps.net/forum/showthread.php?t=29263

I have tried to look at the thread involving Capkid and the above service. However, I get message saying I probably do not have privileges. I would like to find out how to contact him and what is needed for the repair.

Thank you

The HP PL4260N tv I have has gotten worse with the red dots over the years. I am currently waiting on parts to repair the YSUS (Y Sustain Board) and assuming that works, I have read that after repairs the dots have gotten worse. I have had this tv for years and hoping this is something that can be fixed relatively cheap (and hoping it isn't the Plasma panel itself.)

[Alastair E]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

The firmware update of the control-board usually fixes the red-dots/green-dots completely....

Capkid's your guy as you're in the USA. I have the same kit, but based in UK....

[tom66]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

Capkid offers a $22.50 service (+your postage cost) to fix this:
https://www.badcaps.net/forum/showthread.php?t=29263

I have tried to look at the thread involving Capkid and the above service. However, I get message saying I probably do not have privileges. I would like to find out how to contact him and what is needed for the repair.

I think you need to have a few posts on the forum before it'll let you send PMs. However, if you still have problems, let me know and I can contact him on your behalf.

[capkid]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

cinemax111, I haven't been on the forum much lately, but I was alerted to your issue by Alastair E. Let me know if and when you need your board flashed. I've subscribed to this thread.

[wirelicker]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

CapKid.

I also have a HP PL4260N that's been garaged since it was 2 yrs old, apparently due to the same problem, and am hopeful I could enlist your help to get it usable. It sounds like it's the same problem that you've been fixing. Lots of pink/red sparkling, images are terrible, lack brightness and richness, and generally jacked up.

Could you let me know what other symptoms to look for, and if it's something you believe you can fix?

[tom66]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

The red/green dots fault is generally a "watchable" TV but in darker areas, and trailing bright movements, red/green dots can follow objects.
Your fault sounds more like a Z-sustain fault

[wirelicker]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

Tom,

Thanks for your reply. I've attached a pic. I tried to include the cloned imaged (google home page) on both the laptop and tv. As you can see, the camera seems to have adjusted it, because you can't see anything on the laptop. Just wanted to clarify, there is a huge difference between what it should be (like the laptop) and what it is.

Does this confirm your diagnosis?

[Alastair E]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

Wirelicker--

I think there's summit else going on in your set, Check all the various voltages on Y-SUS and dont forget the V-Zbias on the Z-SUS...

Post them here, maybe one of those is off causing the issue.

Is the picture really dark as well?--difficult to see in that picture....

A picture of the chassis and the boards would help identify exactly what model PDP too....

[wirelicker]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

Voltages coming in are good.

Vs 188. Va 66.

Attached a pic of the ZSUS.

[wirelicker]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

zbias is 2.6 - 2.7

[wirelicker]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

Here's what I got, tested Zbias and others at the white connector in photo...

1. OE 0

2. Zbias 2.7

3 Sus_dn 0

4 Sus_Up .26

5. ER_dn 0.082

6. ER_Up .31

[tom66]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

Vzbias should be checked at the point near the orange ribbon connectors.

[wirelicker]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

Let me try that again. Next to the ribbon there is an arrow printed on the board labeled zbias which points to an n-channel mosfet (fqb 27n25 g36). It registered.

G: 7.3

D: .047

S: .138

Another thing I noticed, the heatsink wasn't getting warm on the zsus.

[Alastair E]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

Looks like the VZbias supply is missing....

Its generated on that small sub-board by the side of the MOSFET. Check for the resistance to chassis from the VZbias test-point, (Tab of that mosfet)--maybe there's a short on that line somewhere....

[wirelicker]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

No resistance when powered on.

[wirelicker]

Re: HP PL4260N - Red Dots after YSUS repair - do not disappear after warm

I found a bad fuse on the Zsus. Replaced it, and now the tv won't stay on. It acts like a throws a breaker a second after coming on. When I put the bad fuse back in, it powers up, and I get the same purple/pink and muted screen. The fuse I got to replace it matches spec, (4a, 250v, slow) but is glass instead of ceramic. Since the tv has 5 of the same fuse in different places, I juggled them and tested again, same result.