Hi,
I recently bumped my [url=https://www.badcaps.net/forum/showthread.php?t=45599]old thread[/url] about LG PDP (42V6) problems, but as I solved these problems and a completely new, unrelated problem occured, I decided to create a new topic.
If you could look at this short movie: [url]http://youtube.com/watch?v=Q6qK7zMrJaA[/url]
I recorded how the "No Signal" frame is erased with a 60 FPS camera and stretched it, so the frames can be visible. It is clearly visible that something is wrong with the erase.
Of course, I made adjustments....
Gof
Member
Last Activity: 03-07-2016, 04:24 AM
Joined: 04-11-2015
Location: Warsaw
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Need help with LG PDP waveform regulation (incomplete erase)
Last edited by Gof; 12-01-2015, 03:09 PM. -
Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
I'm happy to bump this thread to say that the problem is mostly fixed. Control board was good (no fw upgrade was needed), but ysus board was faulty. I don't know what failed exactly, but it wasn't the IPM, as I checked it.
Anyway, I replaced the ysus, regulated voltages and two ramps on it and it seems almost ok. I regulated voltages according to the sticker on the panel, not to voltages in service manual, which were different, for example -Vy on panel was -70V and in service manual -75V.
The... -
Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
Yeah, it should be possible to program it with boundary scan, first discovering how the memory pins are connected to the MCM pins.
I have zero experience with JTAG yet, but I'm reading urjtag manual:
[url]http://urjtag.org/book/_jtag_commands.html[/url]
There are two commands that look promising: [b]discovery[/b] and [b]detectflash[/b].
It doesn't seem to support this flash and it supports only one Sharp MCU... but I'll give it a try when the JTAG programmer...Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
Ok, in case someone's interested (maybe someone will find this post looking for the pinout of P9 connector on the web), I've mapped P9 (FPGA_Download) on the control board.
Direction of pins: from left to right.
1. Gnd
2. Gnd
3. Vcc
4. Vcc
5. Flash memory write enable - active low input
6. EPCS1 chip select - active low input, there must be a falling edge after power-up on this pin to begin programming
7. EPCS1 data - data output
8. ? - I couldn't map...Last edited by Gof; 05-02-2015, 12:31 PM.Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
By the way, where do you connect the jig? To the 12-pin port (P9) called "FPGA_Download"?Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
If it's 4MB then it will fit only in the parallel flash, so it must be a firmware for the main CPU. I'm not sure yet what is the simplest way to program it without a jig, but I'll try to find out - there's always an option to unsolder it and program it off-board...
My email is: [email]ohlins@chmurka.net[/email]
Thanks!Re: LG PDP RZ-42PX11 - snow on the d... the main CPU.Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
Oh, and there's one more thing.
On this board there are three different programmable memories.
1. EPCS1, which is a serial configuration device for EP1C3T100 FPGA chip. It has a sticker: 42V6AFPGA2 041223. Memory size: 128kB.
2. M29W320DT, which is a parallel flash memory, I believe it contains firmware run by the LGPCMv12H23 chip. Sticker: 42V6A3MN2D 041223. Memory size: 4MB.
3. AT89C2051 microcontroller. Sticker: 42V6T-01 041223. Memory size: 2kB.
Without...Last edited by Gof; 04-30-2015, 11:37 AM.Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
Hi,
Panel model: there are two stickers with panel model, one says 42V6#### and the second one: PDP42V60000
Part number: 3315Q-E012A
Control board model: 42V6A
Partno printed directly on the PCB: 6870QCE016C
Partno printed on the sticker on the PCB: 6871QCH046C
EP1C3T100C8 FPGA has a sticker that says: 42V6AFPGA2 041223
How would you prefer to send me the FW? Do you want my email, an FTP or SFTP account or something like that?
...Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
I unsoldered them (before reading this post) and it's exactly as you said.
As they're already unsoldered, I'll measure their capacitance and ESR and if they're OK, I'll solder them back (the ones I bought are for lower temperature range, 85°C, so if original ones are good, it would be better to solder them back, as they are rated 105°C).
[b]Alastair E[/b] wrote about upgrading control board firmware. Can it be done without an expensive LG jig, for example using JTAG? There's an RS-232 service...Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
The panel arrived and I swapped it. There are no artefacts, maybe I'm just lucky...
I've noticed two swollen caps (I didn't find them ealier) on the Y board - two 680uF/250V caps. I haven't noticed them ealier
I ordered new ones, maybe it will fix the problem...
Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
My first reaction was like "why would I need FW update when it worked and stopped?", but then I found this post and it explained it:
[url]https://groups.google.com/forum/#!topic/sci.electronics.repair/BwxQni3q2U0[/url]
Quoting:
"Anyway, more importantly the display has a very common fault as in maldischarge (speckles) this is random all over the screen and noticeable mostly on black areas or light to dark transitions." (...) "I believe this is a very common...Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
So the situation now looks like this.
Vscw: should be 115V, was 118.4 ... 119.2V, adjusted.
Vy: should be -75V, was -73.6V on white screen and -76.8V on black screen, I didn't touch it.
Vsetup: should be 200V, was 194-196V, adjusted.
It did not help.
However - could you tell me if my Y waveform is correct? I found a service manual for this panel where it looks like setup1.png (attached), however measured waveform looks like setup2.png (attached). Basically, set_up hold...Last edited by Gof; 04-21-2015, 12:32 PM.Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
I know, thanks.
Well it seems I'm out of luck I replaced the resistor and it did not help. It seems it's like [b]tom66[/b] said that the COF has failed and just took the resistor with it.
There is a used panel available for about $60 on the local auction service (when a used plasma TV like this is available for about $200), I think I'll try to fix the snowing problem first (I'll check all the voltages) and then I'll buy this panel.
Thanks for help!Re: LG PDP RZ-42PX11 -...Last edited by Gof; 04-21-2015, 06:20 AM.Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
It seems that this mark on IC2 is only a minor scratch. I'll be sure when I solder the new resistor (I ordered ten of them and I'm still waiting for them to arrive, I should have them on Tuesday). I'll put everything together then and then check all voltages (previously I've checked Vs and Va only).Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
Seems I might have some luck. There's a 10 ohm SMD resistor (R2 on the picture) that is broken (I measured it and it has a break).
By the way, it's on the power line to limit current spikes that would flow during switching Va because of capacitive character of the panel, right?
Anyway, I'll replace it, but it doesn't fix the second problem - snowing... do you have any idea about this snowing?
Thanks....Last edited by Gof; 04-15-2015, 04:03 AM.Leave a comment:
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Re: LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
So there's a COF there that drives address lines... I thought the flex connects directly to the panel.
There's that long heatsink, so I think it's what you think it is. I'll remove it and check it, thanks....Leave a comment:
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LG PDP RZ-42PX11 - snow on the dark picture (white is OK)
Hi,
First of all, thank you [b]tom66[/b] for sharing your huge knowledge about PDPs!
I have a problem with my LG PDP. Model name is RZ-42PX11. Maybe you (or anyone else) could help?
The first problem is the black, vertical stripe. It is in the part of screen driven directly from the control board (not from XL or XR boards), from P109 connector. I reseated the flex ribbon, but it did not help. Based on your experience, would you expect one of many ACT549 drivers (I believe they are driving the panel address lines, do they?) to be damaged? Maybe you know... -
Re: New Members - please post your introductions here
Hi,
Adam from Warsaw, Poland here. Thanks for making such nice forum!Leave a comment:
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