Re: Samsung PS50C550 (S50FH-YB06) Sound but no picture (or glow)
Thats interesting about the cracks, I know some panels have a sheet of glass before the actual panel, but alot of the newer panels are so thin that I dont think that is the case in this situation.
Although I did manage to get the display to light up for a sec before it shut down in what i suspect is a safety/protect mode.
I disconnected the "data" cable to the YSUS, but left the power cable which feeds the ysus and zsus boards, and the unit powers up without the DRV_Reset error....
zedexnz
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Last Activity: 10-12-2014, 02:23 AM
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Re: Samsung PS50C550 (S50FH-YB06) Sound but no picture (or glow)
Did you end up resolving this????
I have a similar TV which I am working on. If i remove the Y-SUS the rest-drv error disspears, so I am suspecting the y-sus board. With the ysus plugged in, I get the error.
I have noticed that the screen as a few fractures in the glass, and wonder if this has caused extra loading on the ysus board causing it to go bad????Leave a comment:
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Re: Samsung PSU low voltage.
Thanks all, sounds like it must be the logic board, as most other problems of the same model seem to be power board related and differ slightly. Randtek how many units do you see that have had main board issues??? Any managed to fix one?
THanksLeave a comment:
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Re: Samsung PSU low voltage.
pic as attached. Checked all the main diodes as per Wizards post. They are fine. Tried force starting with the 5v -->power on via a resistor on the power board, nothing. From the panel connector its definatly switching, but dont get a power on from the logic board. to the powerboard though. The power on/ stays at 0.7v doesnt seem to switch.
Looking more like the logic board....
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Re: Samsung PSU low voltage.
Thanks Dgtech, I actaully had been reading that thread to see what other solutions others might have found. It looks like the same board is used in quiet a few models and they all share similar faults.
So with your issue it was power board rather than a logic board??? Although you were getting yours to show up with a picture with a flashlight. Mine doesnt even do that and red light doesnt even stay on/flash. It goes on for about a second when you first plug the power in and that its, its stays off.
TEXLeave a comment:
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Re: Samsung PSU low voltage.
I am located in NZ. 240V is our line voltage.
I checked the switch/control board as one of the first things I tried and definatly getting 3.3v and 5.12v at the various points, so its something between the power board and main board. Googling has told me that the samsung have either a cap issue on the power board that causes the eprom on the logic board to go, but I can't seem to find any bad caps or a noticable eprom for that matter.
Ironically the unit has only less than 500 hours use, but was outside of the 1 year warranty...Leave a comment:
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Re: Samsung PSU low voltage.
Sorry Bill you probably see stupid questions like this every day so I appreciate you patience and help.
But yes the values are the same with the logic board plugged in and turned on and off.
Pin1 on/off 0.7V
Pin3 on/off 5.17v
Pin15 on/off 5.13v
Main cap on/off 386vdcLeave a comment:
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Re: Samsung PSU low voltage.
Thanks for the insight Bill.
I can really turn the unit on as such. I dont even get a red light. When the logic board is unplugged the power board at least lights up the backlight of the LCD and this is how I have been doing the testing, with the logic board disconnected.
Pin 3 and pin 15 measure 5.16v with respects to the Gnds on pin 10. The 13V rails with respects to the same Gnd are measuring 12.47v.
The main cap is 340V DC
It is like the reference voltage for the regualting circuit is causing...Leave a comment:
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Samsung PSU low voltage.
LA26B450 - N66D Chassis
BN44-00259A power/inverter board.
Unit does not power up.
If I unplug the logic board, the backlight turns on.
Checked the voltages at the powerboard connector and they all seem slightly too low which is I suspect is the issue. eg (5v rail is measuring around 4.7v. 13v rail is measuring about 12.7)
Caps look ok
I have the schematic, but cant seem to decyper the various parts. They definatly not as good as the sony diagrams I have used in the past.
Not sure where to look, but suspect around the regulating... -
Re: LG PDP42G1 panel help
So i pulled some of the FETs off to test independant of the board. Found that i have two 45F122 which give different readings. Now is there a special way to test these FETS??? Should I be expecting a single junction only?Leave a comment:
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Re: LG PDP42G1 panel help
I have attached a pic of the board. I have checked the FETS and they all seem to be fine after comparing same FET and thier readings.
Checked the most obvious diodes, but many cannot be accessed unless the heatsinks come off....Leave a comment:
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Re: LG PDP42G1 panel help
Thank for the confirmation Ray.
I disconnected the ZSUS for testing, just in case it was something down line that was drawing current.
All the main transistors test fine and there is no visual issues with the buffers I can see. What area of the YSUS should I be looking at next?? For the guys who do component level repair to the YSUS boards, what normally fails?
Thanks, its be a greta learning experience.Leave a comment:
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LG PDP42G1 panel help
Newbie to this and have been doing alot of reading.
Have the above named PDP42G1 panel which is not showing any picture.
Check the Va and VS and they are correct from the power supply board.
When the unit starts up the YSUS and ZSUS boards sound like they are "priming" as in they humm, quiet loudly actaully.
Nothing on the screen and nothing when shining a light on it. ZSUS is feed from the YSUS board.
Checked the VSETUP/-VG as labelled on the board and it looks as if there is something wrong there, but i dont know...
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