I turn this on and the led goes from red to blue as in powering on but no picture. Im thinking main board?
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proscan PLDED3996A-C2 NO PICTURE POWERS ON
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
Can you completely remove the back of the TV and take straight shot pictures of the whole back side of the TV, the power supply/LED driver board (both sides of the board).
That power supply/LED driver board looks familiar.
I would say bad LEDs like this one:
https://www.badcaps.net/forum/showthread.php?t=45652Last edited by budm; 04-16-2015, 09:25 PM.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
I tested them red wires on the connector. They all read 20.7 volts. I think them wires are going to the leds? And shouldnt they read 24volts? Also i took picture of this diode. The board looks really brown burned up right under them 2 big diodes, the picture doesnt show it so good but it looks more burnt then shown in picture. But im thinking if them 20 volts is correct then i proly has bad led lights
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
Did you check both diodes yet? They are connected in parallel.
The 20.7VDC readings on the red wires are ref to the chassis GND, right?Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
Originally posted by mattstolte View Postnot sure what diodes connected in parallel mean but they both read 252 and checked them other way they say 1
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
I just repaired a proscan PLDED3273A-E, that has a different power board but the circuit may be similar. The voltage from the power supply for the led circuit was around 25-30 volts off the diodes, it then goes through the coil and is boosted to around 70 volts, I suspect that boost circuit is not working, if it is the coil should be getting quite warm. if its not getting warm check the boost circuit.
This video has a circuit diagram which may be usefull https://www.youtube.com/watch?v=GrfSmtzFjCcLast edited by R_J; 04-20-2015, 09:52 AM.
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
: I have a PROSCAN PLDED3996A-C2 S/N A1305095130002210. I have sound and no picture. I can see the menu when I shine a flashlight on the screen. I cannot determine what part I need to replace, but its either the power board or LED controller board. I don't believe I have an inverter for the LED or its built into the main board. What part do I need? Model No TH390LK01-ACW1
Cell V390HJ1-P02
T201304032
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
both of you are from Cincinnati? I am from canton area. I have led strips for this model available. what you need to do is test each led with your meter on diode mode. scrap the paint off on each side of the led and test each one they will light up if good just a little from the power on your meter. if they don't light up then its no good, if you need help message me
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
Just for data - I am taking one of these tv's to recycling today because of this same problem. The picture just vanished one day though the sound was good and everything else seemed to be working fine (channels would change/ we could turn it on and off). When I found it was possibly a "video inverter" and that this could be diagnosed by looking for the faintest hint of picture on the screen, I could in fact see a hint of movement when I looked at a severe angle. I took the thing apart after watching a YouTube tutorial that showed how simple it was to pop out an old video inverter and pop in a new one thinking that of course I could order a card and do THAT. Not so simple.
As I said, I'm dropping one of these off to the recycling place today. I wasn't ever even able to find out where the crummy "video inverter" was!
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
What Voltages did you check out so far?
We also need you to upload good clear pictures of the whole back side of the TV showing ALL the boards and then the pictures of the power supply board top and bottom side.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809
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Re: proscan PLDED3996A-C2 NO PICTURE POWERS ON
It's been about 20 years i graduated from electronics school but unfortunately i never worked in the field, went straight to I.T.
I tested the 2 diodes which are in parallel and the 110v input from the connectors on the PCB..I wiggle the PCB back and forth while off and the tv works, i wiggle it back some more and it stops..would be indicator of bad solder, but i redid most of them..
I can post pictures of the power supply back and front but nothing seems darkened or unusual
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