Re: Panasonic sc tnpa5081 rebuild
All tests were conducted without buffer boards/SC50 shorted. I also checked SU/SD boards and they tested good before I started working on SC board.
Have you run into bad 30f125 before ? Out of 16 peices I ordered 2 were having resistance of 300 kohm. I'm checked these fresh out of box as they arrived. I've a feeling some of the other IGBT's might have been DOA and would be the reason for failures.
Have been really busy and haven't started working on removing the failed components from SC board yet....
myfastgti
Member
Last Activity: 02-01-2016, 08:49 PM
Joined: 08-09-2014
Location: Bellevue, Washington
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Re: Panasonic sc tnpa5081 rebuild
3rd attempt failed again with a load pop and back to square one.
One thing I want to bring to attention of everyone is I received 16 pieces of 30f125, out of which 2 pieces have resistance of 27k and 300k compared to rest which showed between 1.7 and 2.0 M Ohm. Not sure if you guys run into these while ordering from Utsource.
Here's the list of components I replaced
D16451
D16482
Q16452
D16702
IC16521
IC16691
IC16724
IC16771
IC16773
...Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
IC 771 is good and I did received IC 773 from Digikey last week, still waiting for 30f125. Since I choose USPS, it'll be at least 2 weeks before I can retest the board.
The r707 3.9 k Ohm was good in both attempts but Q701 didn't survive. I believe there is a 4.7 k ohm resistor across both fets which was giving me reading of less than 100 ohm. Will see once I've all the parts
One last question I wanted to ask is do I need to worry about Q521 CPH5524-TL-E and Q551 CPH5524-TL-E. They seems good as the resistance check...Leave a comment:
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Re: Panasonic sc tnpa5081 rebuild
Thanks tw2005 for helping me identifying the faulty 30f125. Too bad the diode continuity shows both good but resistance check actually confirms if they're good or not. I my case both were around 264 ohms
Have already placed an order with Utsource last week....Leave a comment:
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Re: Panasonic TC-L55E50- Any one seen this problem?
I've seen this before with Panasonic led TV's, if you've 1 sec delay in video then it's panel fault.
Last year someone on ebay was selling T-Con and Main board for $25 but after swapping each board at a time, no luck
One thing you might want to check are the components on tab bondLeave a comment:
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Re: Can you help me find replacement Panasonic tansistors?
You see off, late I've been seeing lots of SC boards failure on 2011 models. And it does seems like to be a design problem as these FET's get too hot and no heat sink may be the reason for early failure.
Looks like Digi Key carry's FGD4536TM at the same price as that of UTSource. I'm curious to know how they perform....Leave a comment:
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Re: Samsung LN32C540F2DXZA: Won't turn on, PS and Inverter OK
You could try replacing the FET, eBay sells them for $2.
Unfortunately I don't have the service manual...Leave a comment:
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Re: Can you help me find replacement Panasonic tansistors?
Thanks Bud, looks like SJ is out of stock. Going to buy from audiolabga. The strange thing is that Panasonic TC-P50ST30 model has SC board IGBT's 30F131 but TC-P55ST30 and P60xxxx has SC board IGBT's DG301's...Leave a comment:
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Re: Can you help me find replacement Panasonic tansistors?
Looks like there are two versions of DG3C3010CL, I wonder what version everyone is selling....Leave a comment:
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Re: Samsung LN32C540F2DXZA: Won't turn on, PS and Inverter OK
Yes its a 8 pin dual n-channel mosfet from Alpha and omega number AO4800BL or AO4801. There should be 12 v or 11.8 v at pins 5,6,7 and 8 when the power button is pressed. If not check if you have any voltage at pin 2 and 4.
Usually these fet's don't fail but so far I've only seen one failureLeave a comment:
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Re: Samsung LN32C540F2DXZA: Won't turn on, PS and Inverter OK
I had Samsung with similar problem and it turned out to be SDRAM was defective.
First heat the SDRAM with heatsink (Big red circle)chip for 30sec and see if the TV turns on if not check the 4 pin mosfet besides the RAM, sometimes it short....Leave a comment:
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Re: Sony kdl32xbr4 Vertical Stripes
Recently I fixed the same set and found the bad resistor was about 10 megaohm in circuit. To check you could just solder another 10K metal film resistor on top and see if that fixes the problem.Leave a comment:
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Re: Toshiba 40rv525u power led flashing / will not come on
I know this is a wrong thread but hope this helps.
I bought a Toshiba 37rv525 last week and found similar problem with power supply having standby voltage 5v varying from 1.2v to 5v and so did the 24v. The person I bought this TV had already replaced the power supply, so I decided to troubleshoot the main board.
Since I've access to scope, I found two SMD 100uf/6.3v (I think) caps way way out of range. Also I had to clean the board with alcohol as there was lot of rust on some of the metal components....Leave a comment:
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Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted
Hi Guys, wanted to give a quick update. Yesterday I got another SD board from the same seller at no extra charge, installed right away and the TV is alive, never thought I would see this day again.
Just wanted to thank everyone who have helped me in diagnosing the problem especially TW and Alastair for your valuable time and great efforts in sharing the information and troubleshooting guide.
Another TV saved from going into recycle. And TW you're right about not to replace the buffer chips cause...Leave a comment:
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Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted
Finally I got the SD board and to my surprise the new board is shorted too. I've ordered new buffer chips from China and will wait to arrive and try not to rip off the tracks while removing the shorted chip.Leave a comment:
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Re: Samsung ln40b630 not turning on
I've seen this behavior with Samsung LN46C530F1F I bought from Craigslist. If you've heat gun or hair dryer try heating the motherboard, especially the memory chips which has heat sink on top around the processor. I solved my problem by replacing the chip K4T1G164QE-HCF8Leave a comment:
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Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted
Thanks tw, I've ordered new SD board and will report back next 3 days.Leave a comment:
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Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted
Thanks tw. I did found a seller from China selling these chips for $5 ea, but like you mentioned it's better to replace the board rather than removing the adhesive and risking to rip off the tracks. I'll go ahead and order new SD board.
One last question I would like ask is, if you've been seeing vertical black lines on the front display of screen mostly caused by improperly seated brown ribbon cables from SU/SD board, then would that cause the buffer chip to blow ?Leave a comment:
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Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted
One interesting and unusual thing I noticed after removing SD board was there was a think layer of dust accumulated on the ribbon cables at each connector. The dust was mostly on the gold plated pins, so that could explain why my SC board kept on blowing all the time as soon as I connected SU/SD board.Leave a comment:
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Re: Panasonic Plasma TC-P50GT30 7 blinks SC board shorted
Thanks for your reply tw, Yes I do have 50gt30 model. So here's what I did after getting the 7 blinks, before removing the SC board I found just Q401 short. So I removed the SC board from the TV and started checking all the test points and to my surprise I found none of the IGBT's were short. So I checked first SU board for short and didn't any connutiny however on the SD board I found one buffer chip short.
So I need all of guys opinion as to whether I should replace the SD board or just replace...Leave a comment:
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