Re: Fixing Phillips LCD TV 37PF7320A
The question is, if the Bl_On is generated in the mainboard or in the AUX PS board. Also, the reason the Bl_On is not generated can be caused by a problem in the main board or AUX PS board, but also in the Power Supply board - maybe the mainboard doesn't detect some voltage or detects a different problem and that's why it doesn't turn on the backlight. How do I find out, what the cause is?
I wish I had the same working TV here to swap some boards. That would be much easier.... :-)
RobPhotoPro
Learning Fast
Last Activity: 09-17-2014, 07:24 PM
Joined: 06-23-2011
Location: Charlotte, North Carolina, U.S.A.
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Re: Fixing Phillips LCD TV 37PF7320A
There's no voltage on pins 11 and 12. I have the service manual, but no idea, how to troubleshoot or trace missing Bl_On. In the start-up sequence it looks, the backlight is turned on as last. The fact, that motherboard doesn't send the signal can be caused by many factors and the problem can be anywhere. I would love to isolate the faulty board at least.Leave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
Thanks for your help, guys!Leave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
The resistor seems to be fine, measures 100 ohms, as it should.
Thank you.Leave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
After some time I got back with this TV. I measured the inverter boards inputs - flat connectors connecting inventors with Aux Power Supply board and noticed, they supply 24V, but no other voltage (like Bl_On). So it looks, Bl_On is missing and the question is, what board is in fault.
Any suggestions?
Thanks!Leave a comment:
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Re: Philips 37PFL5322D/37 Chirping from psu
I was just wondering, what the exact position of the faulty diode was (like D925 ...)
Congrats to your successful repair!Leave a comment:
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Re: Samsung HP-R4252 42" Plasma No Picture
This is, how I tested the main Y-sus IC:
[url]http://blog.coppelltvrepair.com/2011/04/how-to-test-stk795-518-ysus-ipm-for.html[/url]
My IC passed all tests okay.Re: Samsung HP-R4252 42" Plasma No P...ll tests okay.Re: Samsung HP-R4252 42" Plasma No Picture
This is, how I tested the mainLeave a comment:
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Re: Samsung HP-R4252 42" Plasma No Picture
Well, I was lucky to get a replacement lower Y-buffer board from E-bay for $ 36.00, shipping included. The upper buffer tests okay.
So the only problem seems to somewhere on Y-sustain board. I replaced the shorted FET and the main IC tested okay. What else does usually go bad on this board? How can I test the board to make sure, the problem is not somewhere else? Too bad I don't have a similar, working TV to test the boards.... :-(
Thanks,
RobLeave a comment:
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Samsung HP-R4252 42" Plasma No Picture
No picture symptom on this plasma TV suggested a problem with Y-sustain board and Y-buffers. It features problematic LJ92-01203A / LJ41-02761A and LJ92-01202A / LJ41-02760A with 6 ICs. I checked out Coppell Repair Blogs and some threads here, that helped me to identify shorted buffer and a shorted power FET.
I replaced a shorted lower buffer and one bad IXTA36N30P power fet under the heat sink on the Y-sustain board.
The TV still powers up and stays on with NO picture. I even tried connecting one buffer at a time - no half picture. Checked the voltages, Vscan is... -
Re: Phillips 42PF7321D/37 Plasma No Video
Hey Mike! What's the status of your TV repair? I'm working on a TV with the same internals (Samsung HP-R4252). So far I replaced one shorted mosfet under the heatsink and got a replacement lower Y-buffer, which had two ICs shorted.
So now, after powering up the TV, still no picture .... Nothing's blowing up either.
Any idea, how to proceed?
Also, what open fuse did you replace on the Y-sustain (the one supplying 10V)?
Thanks!Leave a comment:
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Re: Rubycon YK substitute
Would Nichicon VR work? (ripple current - 1.55A)Leave a comment:
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Rubycon YK substitute
What would be a good substitute for a Rubycon YK series 2200uF 25V 85C capacitor? Length not more then 27mm, preferably available at DigiKey at the moment?
Thanks for your suggestions! -
Re: Fixing Phillips LCD TV 37PF7320A
Sounds great! Thanks, PlainBill!Leave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
I have no idea how to diagnose or fix any of those. Where's my hammer?! :-)Leave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
Thank you, PlainBill. I appreciate it!
And as I mentioned before, when the TV is on for about 10 seconds, the sound works well, you can even change volume and channels without a problem. But no picture and then it all goes to protection..... I wish I had a couple of boards to swap, to at least identify the faulty board.....
Thanks again!
RobLeave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
I bet! Florida is too hot for me in summer! :-)Leave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
Any ideas? Anyone?
Thank you!Leave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
I have a Innova 3320 multimeter, it's autorange. It also has a diode testing mode, which I used after I took it out of circuit. I also used an ohmeter out of circuit, it was never 0.
When testing in the circuit, it measured inconsistently.Leave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
It looks I will need more of your help afterall. I checked the diode out of circuit and it measured fine. The same for the second diode on that board.
So now I am lost. Would you suggest to replace the capacitors? They look fine and unfortunately I do not have a capacitor tester.
Thank you,
RobLeave a comment:
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Re: Fixing Phillips LCD TV 37PF7320A
I attached an image with what I think is the aux power supply. I circled two possible faulty components - 10uF, 450V capacitors and a diode (6113). I measured the diode using ohmmeter and it reads 0, like it's shorted.
Please let me know your thoughts.
Thanks a lot!
Rob...Leave a comment:
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