Re: PS58C7000 sound but no picture
Is this because the power supply design for Vs is basically inadequate for the panels power demands under high-bright loads?
I'm just about to start the firmware update now. more to come soon...
DoubleDratt88
Senior Member
Last Activity: 04-21-2017, 11:56 PM
Joined: 08-25-2013
Location: Melbourne
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Re: PS58C7000 sound but no picture
I made sure the fuse I replaced it with was identical, like i said above. 8A 125v(marked F8R) i believe but don't quote me on that and check your own to be sure to anyone reading this trying to troubleshoot. It's printed on the board right near the fuse.
A bit annoyed at myself for not noticing it earlier though. Now I have a spare y-main I never needed, but that's never really a bad thing to have for a plasma I suppose.
Thanks for the tips on adjusting for the purple tom.
I'll be honest I'm skeptical...Leave a comment:
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Re: PS58C7000 sound but no picture
Update: It's up and running!
I removed everything in the way of the 3 lower boards(a real bugger to get at) disconnected them all from each other and poked around searching for shorts, half expecting to find a failed diode or cap- especially between the previously missing 55v Va rail and ground, but couldn't find anything unusual at all.
So i hooked everything back up and salvaged an identical fuse from another parts tv I was lucky enough to have around, fired it up with fingers crossed figuring there was...Leave a comment:
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Re: PS58C7000 sound but no picture
On the trail now.. - See pics below.
The tv is still on the stand, so can't access these boards yet. Next step will be to get it down off the stand and pull the boards and look for reasons why this might has happened.
Fingers crossed....Leave a comment:
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Re: PS58C7000 sound but no picture
Sorry I should have mentioned but my post was long enough already, I had already tried the linked test and just to humor myself I just went and tried it again a minute ago to be sure and no change in results, still just a blank screen.
I have read of a purple band of death on these models, any idea if that can progress to the point the panel goes blank?
I would have guessed washed out purple instead of blank.. In any case the owner did mention a minor purple band before it stopped working. Voltages do not appear to have been...Leave a comment:
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PS58C7000 sound but no picture
Greetings all,
Trying to troubleshoot a Samsung PS58C7000 with working functions and sound but no picture.
Have tried replacing the y-main board, but no change.
Vital signs are all good, Vs209, Va55, Ve90, Vsc-200. Vsch I think was about -40.
Logic heartbeat LED regular on/off 1 sec.
The panel is firing up and switching on blank - no signs of cracks or physical damage in that state but I don't really know for certain the history. "just stopped working" is all I have to go on.
Removing either y-buffer 1 at a time results... -
Re: Samsung PN42B450B1D Bad Panel?
Strange result.
I'm not sure sorry, but it was worth a try :-)
Edit: I was too slow!
Sorry I can't be of more help,
DD.Leave a comment:
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Re: Samsung PN42B450B1D Bad Panel?
There should be some info on this in the service manual, but basically on the logic main board in the 5th image, there is a group of 4 pins. By placing a jumper on pins 3-4 and disconnecting the ribbon between the logic and main boards then powering on the set you can access a built in self test to try and isolate the main board as the problem.
Edit: see the 2nd post from tom in this link- [url]https://www.badcaps.net/forum/showthread.php?t=26790[/url]
If the test results in full screen colors and patterns then the...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
Thanks tw!
I've had a few other things to do lately so this got put aside but will get into again soon.
IC773 and 771 look suspect, Q701 702 i'm also suss on and will confirm out of circuit later this time.
I reckon it's one of those little buggers i missed last time around - even though i was looking at them on a list in red after seeing your 5081 experiences.
In any case that sounds like a very similar problem, closer than others. I'll have a good read and get back into later tonight hopefully. I...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
Oops don't know how I missed that. Was tired I guess?
After reading i looked quickly in the schematic and the only q604 i could find was on the p board - didn't see the obvious q604 right next to the diode until now sorry.
The Q604 on the SC board, looks fine to me :P
The internal diode between source and drain on it tests good and gate is insulated. no low ohm readings.
Thanks for the soldering tips, I've tried flooding pins a couple of times before with mixed results(lifted pads) but...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
Hey glad to see you back - Hope the holiday to broken panny paradise island went well. Possibly only you and tom would think of that as a great place for a vacation though
Just a quick answer to your query for now sorry, I might post some more details later if they're needed.
As soon as I can I will start removing bits in the ic501,ic771 area. Probably start with the reg and inverters since those pullup resistor readings for the inverters seem off and the reg is almost as good as shorted compared to the...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
Update: I jumped the gun calling Q661(RJP6065) ok earlier. It is shorted source-drain and NOT ok, not switching.
The last 2 Q661's were shorted across all 3 pins so this one a bit different fooled me at first. The rest was accurate though and 401 is toast, 402 still operational.
Those 3 are all I removed so far, so seems on the right track.
The whole area around IC771 and the IC501 fet driver seems suspect including the 2 HA inverters IC464 and IC465 which both show 35.5ohms between VCC and gnd pins - just...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
I think I'm onto somethings. Not sure exactly what though! hah.. (long, details below)
First main thing is IC 771(5v reg) resistance:
Positive > negative-
pin 2 to pin 1- 35.5 ohm
pin 2 to pin 3- 129 ohm
pin 1 to pin 3- 163 ohm
Negative > positive-
pin 2 to pin 1- 35.5 ohm
pin 2 to pin 3- 128 ohm
pin 1 to pin 3- 162 ohm
Not sure if the regulator itself is the cause of these low readings but seems suspect. Still checking things before removing...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
I removed Q401, Q402 and Q661 to confirm the above ^
~ The Blinks:
The most common info i can find on 2 blinks is a failed mc201 or mc301 daughter board ic where a ceramic cap or ic can often fail.
This 42s10a however does not even have that daughter board ic on the P board. There is a similar one on the SC board itself, IC791. It has heat shrink covering it though so i cannot see if it has the TEA1611 etc without cutting that off.
Since i heard and smelled the released magic smoke myself I am...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
SC out -
Q401 blown, 402 survived
D865 ok
Q661 ok
Probably more to come, still poking around. Any pointers or ideas welcome and appreciated. Seems even more unusual now.Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
D619 test's ok after all. Still looks like it got hot but not to melting point, just charred.
The good news is D865 tests ok this time.
Board still not out, time to do that.Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
Update: Bummer #2!
Just switched on after replacing the same components as first time and this time got a fairly quiet crackle and pop and some magic smoke as soon as the switch went to on.
Now shows 2 blinks
Not sure why this would have happened, I'm sure there's plenty of reasons.
After a quick search 2 blinks is apparently 15v sos.
With SC disconnected:
6 blinks and SS led ok, p15v at p25 pin 1 rises to approx 15.8v, p5v at p25 pin 6 4.99v.
...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
I have now researched many hours on this thing and checked everything that's been suggested here and in other threads, compared parts to those listed in repair kits etc and keep coming up with nothing.
The closest i found to another component out of tolerance was 2 identical 5%(3.75) 75 ohm resistors, reading 72ohms and 72.35. For reference they were R504 and R523.
Have checked:
All other heatsinked parts checking ok, no shorts, diodes ok.
IC771 and nearby
IC773 and nearby
IC521,501...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
Minor udate-
PC461 is not it - atleast not on the input side, the output transistors in it are still untested but we know they worked for atleast 90 mins.
So that theory can be dismissed and your stuff is safe from probing for another day sir! (again, thanks though!)
Your suggestion that it could be just dud/fake/igbt failure may well be correct.
PC461 tested normally once the 390ohm resistor on pin 3 was removed- so the reading was coming via another path and not backwards through the...Leave a comment:
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Re: Panasonic Viera TH-P42S10A SOS 5 Blinks
I would surely have to be more likely to destroy it before that happens!
Here's my new plan:
Work dangit!
Really though I don't have any plans of going nuts and have very little $ invested in it. I got it for the cost of a beer and fuel getting it home pretty much, and the parts I've damaged so far have been <$15. If I can keep to numbers like that it's hard to go wrong really for a project that might possibly end with a working 1080 panny.
Pretty amazing tv. It's already...Leave a comment:
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