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Old 12-13-2013, 11:45 PM   #1
jreads
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Default Wal-mart display tv woes.

Hi all, I have on my hands a Panasonic tc-p42x5 on my hands. It was a Wal-Mart display tv, and I've been having some problems with it. Ok, well when I unplug it, it doesn't want to turn back on for days but eventually it will. At least it has every other time. The first time this happened it took about three days to turn back on, the next time it took around 5 days, and this time im still currently waiting. So, basically what's going on is the set is completely dead no standby power or lights. What im wondering is what could be causing this. Would it be my power supply or the main board? Any feedback is greatly appreciated.
Thanks in advance,
Jake
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Old 12-14-2013, 08:50 AM   #2
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Default Re: Wal-mart display tv woes.

Most likely bad capacitors in the power supply.
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Old 12-14-2013, 12:48 PM   #3
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Default Re: Wal-mart display tv woes.

with an X5 (2012) that would be rare, my guess would be cold joints on PSU as have heard of this on these sets, if not then main board is a possibility.
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Old 12-14-2013, 06:13 PM   #4
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Default Re: Wal-mart display tv woes.

Definitely possible for it to have bad caps. Those display units run 24/7 for possibly months at a time. You take a TV that has been on display for 90 days and it is theoretically possible to have more than 2000 hours on it. Throw in some marginal quality caps and you got a recipe for an early death.
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Old 12-14-2013, 06:17 PM   #5
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Default Re: Wal-mart display tv woes.

Quote:
Originally Posted by tom66 View Post
with an X5 (2012) that would be rare,
Those fail-mart models are built to price. Craps will be a given, as manufacturers don't even get shelf space unless they meet price "guidlines."

Incidentally, this ultimately led to RCA's last CRT plant closing. Suck-mart sets the price, and OEMs are "encouraged" to go lower.

There's "Panasonic" and there's Panasonic.
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Old 12-15-2013, 04:24 AM   #6
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Default Re: Wal-mart display tv woes.

Yeah, well at least this set has Panasonic panel and parts, it's just made very, very poorly.
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Old 03-12-2014, 06:56 AM   #7
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Default Re: Wal-mart display tv woes.

possible solution I stumbled across.

Plasma tv Panasonic GPF15DE Chassis can cause not powering on & standby LED lit
can be very intermittent
.
At a certain sequence of events, the TV does not turn on
and the standby LED is not lit. For example, after disconnecting
of power, then after you turn
within 3 minutes. This modification applies to all
PSU with serial number earlier than below:
42 N0AE6JK00005 **-2550001
50 N0AE6JK00006 **-2560001

TCZAA6755U IC ref (U203)

Not 100% if datasheet is correct device or proprietary for Panasonic by Fairchild.

Does look like FAN6755UW going by the format in the sheet.

Translated some other info.

Some links for the IC

http://www.ebay.com.au/itm/PANASONIC...-/160971382674

http://www.ohmsupplies.co.uk/TCZAA67...42X50-TXP50X50

http://www.notobsolete.co.uk/index.p...oducts_id=1209

http://www.chsinteractive.co.uk/elec...-panasonic.htm
Attached Images
File Type: jpg guide.jpg (72.2 KB, 84 views)
File Type: jpg Tczaa6755U.jpg (3.4 KB, 58 views)
Attached Files
File Type: pdf FAN6755W.pdf (1.20 MB, 90 views)
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Old 07-29-2014, 01:41 PM   #8
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Default Re: Wal-mart display tv woes.

I just bought a completely dead Panasonic TC-P42X5 to "attempt" repair. It has no power or lights. I have not opened it up yet but if I do not see any obvious bad caps, etc. are you thinking replacing the U203 may repair it? Have you attempted this successfully? Open to further suggestions/ideas.
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Old 07-30-2014, 02:41 AM   #9
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Default Re: Wal-mart display tv woes.

Quote:
Originally Posted by AWTVs View Post
I just bought a completely dead Panasonic TC-P42X5 to "attempt" repair. It has no power or lights. I have not opened it up yet but if I do not see any obvious bad caps, etc. are you thinking replacing the U203 may repair it? Have you attempted this successfully? Open to further suggestions/ideas.
No but from what I've read seems to be a common issue and this is the info I found. Do not read much on that series here so looks like they may be fairly reliable otherwise. Only faults I've read point to PSU being dead after a power outage or similar dead PSU.

Totally dead with no stdby LED, I'd be giving this single IC a shot. Why not try it and be the first to report back. I don't think it's terribly expensive chip.
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Old 07-30-2014, 08:13 AM   #10
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Default Re: Wal-mart display tv woes.

You'll have to check if you have the standby 5V. Most Panasonics don't display the red LED until its actually turned on. If the main board is bad, then it won't send the signal to turn it on.
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Old 11-26-2014, 06:57 PM   #11
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Default Panasonic TC-P42X5

Just wanted to report that I saw the same "lack-of-standby" issue on a TC-P42X5 built in 2012 that I traced back to U203 before finding this thread.

If you have one of these similar models that seems to take forever after a power loss to actually "reset" and come into standby (and in this case eventually went totally dead, never came up to standby power), changing that Fairchild 6755 at U203 (a small 8-pin surface mount with one pin missing) power supply controller IC fixed the problem.

I ordered up 10 of them since this looks like a common problem and I know of several out in the field that I'd be likely to be the one doing service on and that this problem may well develop in some of them.

Easy fix, now I know exactly what to look for when it's this problem.

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Old 11-27-2014, 01:15 AM   #12
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Default Re: Wal-mart display tv woes.

Hmm does the ic have a manufacturing defect or is the circuit it's in too demanding ? ie is this repair likely to fail again in two years or two thousand miles whichever comes first...
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Old 11-27-2014, 01:04 PM   #13
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Default Re: Wal-mart display tv woes.

Quote:
Originally Posted by mmartell View Post
Hmm does the ic have a manufacturing defect or is the circuit it's in too demanding ? ie is this repair likely to fail again in two years or two thousand miles whichever comes first...
The circuit looks very similar to the examples in the datasheet and this particular TV showed this probelm essentially from new (first time the power was lost it didn't want to come back to standby for a day) so I think it's more of a defective IC problem rather than circuit design

I know of several other people with this model TV where they have had no problems yet whatsoever.
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Old 11-27-2014, 11:02 PM   #14
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Default Re: Wal-mart display tv woes.

Bad batch of ic's then.
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Old 11-28-2014, 04:21 PM   #15
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Default Re: Wal-mart display tv woes.

That IC is running 24/7 so it is exposed to any spikes, surges, etc. 24/7.
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Old 01-10-2015, 09:11 AM   #16
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Default Re: Wal-mart display tv woes: Panasonic TC-P42x5

Glad I came across this forum! Panasonic TC-P42X5 plasma won't power on anymore after a power cycle. Only two year old. Checked fuses, were fine. Measured voltage at Vdd and got nothing. Figured the power board. Almost pulled the plug on a power board from eBay for $80 but decided to do a little search and found this forum. Went ahead and ordered a couple of FAN6755U (U203)from eBay for $3. Just got Em and replaced it on the board. Lo and behold, tv is up and running. Thanks Guys!!
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Old 01-31-2015, 10:28 PM   #17
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Default Re: Wal-mart display tv woes.

Hi,

First time poster here with exactly the same model and issues, including the tv taking time to reset after power outages or, in this case, after I unplugged it to move it to a new room. Not a good thing with the Super Bowl tomorrow.

My problem is this; where is this chip found and on which board? I can't tell from the images linked above. Is it on the back of the "main" board with all the hdmi and other connectors, or is it on the larger power supply board?

I would be thrilled to fix the unit with a simple IC replacement. I once repaired the reverb on a Peavey guitar amp the same way. The knowledge shared on the nternet can be wonderful, can't it?
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Old 04-06-2015, 10:03 AM   #18
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Default Re: Wal-mart display tv woes.

http://www.ebay.com/itm/5PCS-FAN6755...item1e940bcc79
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Old 07-10-2015, 11:13 PM   #19
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Default Re: Wal-mart display tv woes: Panasonic TC-P42x5

Quote:
Originally Posted by Achilles View Post
Glad I came across this forum! Panasonic TC-P42X5 plasma won't power on anymore after a power cycle. Only two year old. Checked fuses, were fine. Measured voltage at Vdd and got nothing. Figured the power board. Almost pulled the plug on a power board from eBay for $80 but decided to do a little search and found this forum. Went ahead and ordered a couple of FAN6755U (U203)from eBay for $3. Just got Em and replaced it on the board. Lo and behold, tv is up and running. Thanks Guys!!
Guys just wonder if it is possible to get a crash-course on how to replace this things on my Panasonics power supply unit. Thanks a lot, I appreciate it!
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