Hi guys, So im trying to fault find a Panasonic 42" plasma - P42x20b, the 4 blinks tells me its a power board SOS problem, caps look OK, FET's seem to test ok, I have standby voltage, I think i have 15Vdc, Then it shuts down faster than i can measure anything else, i dont really want to pay 350 for a second hand boeard, thanks in advance.
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Re: Panasonic LSEP1287 4 blinks
Check the SS board Vsus rail, shorted RJP30E4 x 4 -
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Re: Panasonic LSEP1287 4 blinks
OK so i figured the SOS signal is coming from this chip (pin 17 /SOS4_H) ?
So what signals would generate this alarm if missing ?Comment
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Re: Panasonic LSEP1287 4 blinks
Ok, I'll make it easier for you. The P board is shorted by the SS board(most likely) on the 200v vsus line and triggering the SOS4.
Disconnect SN2, Sn20, SS11, P35, and the 3 white ribbons at the A board. Turn TV on. Should turn on and stay on and you'll be able to check all voltages if you wish. Don't reconnect any power leads for 5-10 mins, don't run the TV more than 30secs like this.
If it all goes to plan, this proves A and P boards are ok. Then investigate the SS ( SS11 TPVSUS will be shorted)Last edited by tw2005; 12-28-2014, 04:14 AM.Comment
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Re: Panasonic LSEP1287 4 blinks
If your going to run the TV with just the SS isolated, make sure SS11 and SS3 are disconnected. i have managed to blow up a good SN board powering up forgetting to isolate SS3.
Sometimes both SN and SS blow together due to the SS being connected to the SNComment
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Re: Panasonic LSEP1287 4 blinks
Are these suitable replacements ?
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Re: Panasonic LSEP1287 4 blinks
ok, thanks, I will have to purchase from eBay for conveinenceComment
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Re: Panasonic LSEP1287 4 blinks
Bugger ! Replaced the 4 RJP30E4, powered it up, a large buzzing noise occurred, a flash of smoke from the right hand side of the set as you look at from the front, now im getting 8 red flashes :-(Comment
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Re: Panasonic LSEP1287 4 blinks
Sounds like the SN was bad also. I guess the SS is shorted again too. Did you check out the Sn at all for shorted IGBTs. They're a bugger of a Tv to get right.Comment
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Re: Panasonic LSEP1287 4 blinks
maybe have a read
https://www.badcaps.net/forum/showth...npa5066&page=4
may give some clues what can fail.Comment
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Re: Panasonic LSEP1287 4 blinks
OK so the RJP30E4 's survived, i have thre shorted components on SN
DG501RP
FU20 TM5S
RJP63f3A
UT source have all these in stock but something wrong with their payment page, any other reliable sources you could recomend to supply all these in one easy transaction ?Comment
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Re: Panasonic LSEP1287 4 blinks
Rjp63 - q661
Fu20 - d481
Dg501- q451
This is turning into something financially uneconomical to repair if this doesn't fix itComment
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Re: Panasonic LSEP1287 4 blinks
Unless you get the bits from china, yes as I have a feeling there's a reasonable chance the SN may still be bad with just those replaced.
maybe PM Flocko if he's around? He's done a few of these sets now and had a couple of failed attempts on the Sn as have I but has more experience.
I have a SN laying around to compare readings to and a SS.Comment
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Re: Panasonic LSEP1287 4 blinks
Yeah, with Q661 shorted, you probably have parts faulty in the IC773 circuit as well. You should take tw2005 up on his offer to give you readings from his SN board and compare the readings then to your board. It really helpsComment
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Hello! yes I know there is already lots of information about this issue. I have a Panasonic TC-P55ST50 that originally displayed an 8-blink error code. Following the troubleshooting flowchart, I ended up replacing the SS board. However, even after replacing it, the issue persists. The TV turns on and stays on without displaying an image, and continuity is confirmed on all connectors. What am I missing here🤔?
Ok Im a mechanical engineer ...but I thought I was able to follow a rather simple flowchart for electric troubleshooting 😂.
TV Model: Panasonic TC-P55ST50
...11-20-2024, 08:52 PM -
Bought this TV used not working, panel flashed briefly on power up and it was blinking 8 times, a quick look on SS board revealed a common fault on the 3uF 250V capacitors, C201 to C205 (C1620X in the service manual), the solder joints were all cracked, C201 and C205 pins were darkened and some sparking had occurred on them, C201 was split open and clearly overheated in its last hours, replaced that one and resoldered the others, 8 blinks fixed.
Also the previous owner broke the antenna connector by taking the TV out of the wall mount forgetting to unplug it, I desoldered the tuner... -
Hi,
anyone able to provide the service manual for old plasma Panasonic TX-P42ST50E?
It turns off almost immediately (0~5 seconds after pressing the on/off button) and starts flashing the red diode 6 times.
I disconnected the left-hand side board (SC?, both the ribbon cable and the power cable to it) and also another ribbon going to bottom left board. Then the led signal is 8 flashes. According to service guide to another Panasonic plasma it would mean the left-hand side board is faulty. But I'm not sure it 100% applies to my model.
I checked that board for any obvious faults... -
Hello,
Stopped by this site trying to fix my parents Panasonic Plasma TV.
Model number is TH-50PZ85U
Power comes on and the red power light stays on solid.
Did a few checks like hold the power button on for 60 seconds, hold the - Volume while holding the menu button, no luck, still@ blank grey screen as the screen lights up very vague.
I also hear a few clicks.
I also think my parents said there was a thunderstorm and the TV failed after that.
Section 6 in the service manual talks about power and no screen,...10-30-2024, 10:09 AM -
Hello all,
As the title states, I followed the troubleshooting guide located here: https://www.manualslib.com/manual/23...page=53#manual, which concluded the 'A' board needs to be replaced. Looking around the net and eBay, I see that there are repair services for the board (TNPH1043UE? Not sure if it is a 'UE' as the suffix grid does not appear marked). What additional troubleshooting can be performed to ensure 1) this board is the problem and 2) since there are repair services, what are they fixing on the board?) I expected 3.3V not to be available anywhere...
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