Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

[tw2005]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

Nice, thanks. Can you link to the full service manual? (Time to brush up on my Brazillian Portuguese?)

Actually for Brazilians, there's 98% English in this. 50GT30A, portions of the cct crossover from model to model so it's useful.

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

Thanks, will have a look.
Going to try and pick up two more PZ80s this week... (both 10 blinks)

[tw2005]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

Thanks, will have a look.
Going to try and pick up two more PZ80s this week... (both 10 blinks)

Yeah, it's hard not to snap the easy ones for a quick sale. Mind you , once you master something, it can become a bit mundane. They're a solid TV.

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

Yeah, they're nothing much special. Well built beasts, consistent and easy to fix, but a modern LCD will beat the black level on them, colour depth and accuracy though, only a newer plasma (Kuro or this set possibly) will beat them. Plus a lot of power electronics, I do like Putting the money towards my car/insurance fund.

I'm looking forward to seeing how the image quality is on these - though Alastair has warned me of the floating black issue, which I will NOT like. Hopefully, there's a way to turn that off.

[Alastair E]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

Yeah, they're nothing much special. Well built beasts, consistent and easy to fix, but a modern LCD will beat the black level on them, colour depth and accuracy though, only a newer plasma (Kuro or this set possibly) will beat them. Plus a lot of power electronics, I do like Putting the money towards my car/insurance fund.

I'm looking forward to seeing how the image quality is on these - though Alastair has warned me of the floating black issue, which I will NOT like. Hopefully, there's a way to turn that off.

Well--Wow Tom, I can Never find ANY PZ80's round here at all,--only working ones, and whats the point in a Working set!, and there's you getting Two in one weeK!!
Even all my time at the waste-transfer, Never saw one of em. Closest was this 720 PX80--Which is STILL bugging me....

Aye--The Picture on the U30 is good for resolution--even on std. freeview and lacks the DVB artifacts that my ancient PZ70 has, but otherwise, PZ70 beats the crap outta the U30, with its flickering half-lights and irritating floating blacks IMHO--just seems a more natural picture--and Brighter too, and Brill on Blu-Ray....

The U30--especially on a proper Scope film--ie, Letterboxed has a sea of muddy greenish fog that appears and disappears with picture-content on the areas of black above and below the Scope picture, but was the flicker I couldn't stand and finally decided me to get shot....

--I hope you are not too disappointed in its performance, after all the work involved when it fires up with those new parts....

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

Well, I pick up PZ80s about once a month or every two months, although I've had a bit of a "bumper crop" so to speak, with four this month. Though I do have that PZ8BA with a bad main board, which is still "in the pile", so to speak.

2 or 10 blinks is the most common fault and I can do one of them in about 15~20 minutes now. Taking the set apart and putting it back together takes the longest... I pick them up for £30 to £50 and sell them for about £200 each to very satisfied customers (though it's getting harder to sell plasmas nowadays; people don't appreciate the differences in the technology.)

U30 flicker could be caused by being in Cinema/Movie mode instead of Standard, perhaps?

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

Good progress on the repair. I've got an image! Will update more later...

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

I don't like the image at all on this panel. I guess that's a case of "I told you so!"

Alastair do you remember this panel having a lot of image retention / ghosting from previous images? Not sure if this is normal, but I've not done that many newer plasmas. A menu up for about 30 seconds leaves a ghost in the black level. My ultra-dark Kuro doesn't get any image retention at all -- why does this panel?

[Hombre]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

I had two 42S30 and both had retention, altough one was relatively ok, but the other was really bad.

[Alastair E]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

I cant say that I made a particular note of image-retention,--Only when the V-SUS was low via the 150W bulb...

I didnt notice it when the set was all finished, but then again I didnt actually look for it or had a menu up for that long, All tuning etc had already been done while it was bulbed....

How many hours on yours, Tom? Mine had 8000.

I just Didn't Like the picture either--for the faults I mentioned. I was actually pretty disappointed in its performance TBH, I was thinking during the repair process of 'upgrading' from my PZ70, but such a move would have been a big downgrade I think....

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

I'll check tonight.

IR definitely appears on the panel with static images, and it's quite noticeable TBH....

This set uses a "scanning black level" which is kind of interesting - you can see the black level running down the panel in parts when you look up close.

Also - it'll run with the SS out! The image almost completely disappears aside from very faint grey lines. Noticed this accidentally when I failed to connect the SS board.

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

When I initially fired up the set, it powered on and the screen glowed briefly, the ERC LED lit then went out. This was because the ERC driver transistor was not properly soldered.

This was easy enough to see on the scope after I repaired the set, the gate waveform is in purple (MATH difference of CH1 & CH2), blue is emitter, yellow is gate. Unfortunately I didn't think to save the before photo but the purple trace was essentially dead -- there was no significant difference between yellow and blue.

[Alastair E]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

Do you notice that sort of flicker on half-lights I found annoying....?

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

To be honest no. There's more dithering then other panels. I can see some in the corner of my eye but that's normal for all plasmas.

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

I've noticed the pic looks a lot better when I turn off "C.A.T.S."... seems to be some kind of energy saving feature. Makes it look rubbish!

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

7,195 hours / 3,000 cycles BTW.

[tw2005]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

To be honest no. There's more dithering then other panels. I can see some in the corner of my eye but that's normal for all plasmas.

To be honest, comparing my 2010 FHD back to either my 2009 HD or the PZ800 when up close too it, it's noticeable. Picture is still good but you can tell they've tried to dial out power usage. The other 2 models do appear to be sharper and brighter with less "dithering"

[tom66]

Re: Panasonic TX-P42U30B locked out LED (no blink code), SN dead short

Yeah, it's understandable. It's also a base-model FHD set, as low as £379 when it came out (that's about $700 AUD) so they've had to make some compromises. The transistors barely run warm even on a full white pattern, so I'm not convinced (like AS15-F chip failure) that it's particularly heat related. Would like to see a G-series or V-series 2011 set soon, will keep an eye out, this was a lucky find on the local classifieds. Paid a little more than I rightly should have for a 42" FHD set with only 2 HDMIs (it does have a HD OTA tuner which is nice) but it's been an interesting one to fix.

This is my second sustain board repair. Also did that 50" FHD LG with the bad Z-sustain Vzbias ckt. Until now I've not really had to do one properly. Done tons of power boards though. Hope I can do some more Panny and discrete Samsung/LG sets. Work slow, use the scope & meter to check everything, and I might not blow the next one up

BTW, total parts replaced:
4 x 30F131 (Q401,402,421,422)
1 x DG302 (Q441)
2 x Rohm Gate Driver (IC501,502)
2 x Dual Transistor (Q501,531)

about £18 for the repair (TV was £50)

Though the SUS high stuff was probably OK, I could not test it reliably, so it was replaced anyway.

Parts acquired from Alastair on this forum (thanks!) and CHS (who were abnormally cheap...)