I have this usp440m-42lp psu board that has a short on it somewhere causing the fuse to blow, i replaced the bridge rectifier becuase it was short and two thermal resistors before it that were open circuit but problem still persists, can anyone link to a schematic for this board as i cant seem to find one, many thanks will
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Re: lg 42" plasma, usp440m-42lp psu problem
Have you checked the various MOSFETS on the board, eg--the PFC ones, and the chip that drives the Stby supplies?
I dont recognise that model-number--What chassis number is on the panel itself...?
A pic of the PSU and its board number may help....TELEFIX
How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
http://www.irf.com/technical-info/appnotes/an-1088.pdf
PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM! -
Re: lg 42" plasma, usp440m-42lp psu problem
hi thanks for trying to help, i should of stated in my original post that im quite new to this type of work and am trying to learn by doing things, please excuse my stupidity haha, had to google wht a pfc mosfet was, going to check those tommorow, presumably they have to be tested out of circuit?, thanksComment
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Re: lg 42" plasma, usp440m-42lp psu problem
the board is exactly like this https://encrypted-tbn2.gstatic.com/i...BJi2nlPA_kFzr5 it comes from a lg pdp42v7 if thats of any further help,
thanksComment
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Re: lg 42" plasma, usp440m-42lp psu problem
42V7 is the main number that chassis goes by--Its been used in herds of different sets, and with a variety of different PSU's too....
A pretty old set--I wouldnt waste any dosh on it like investing in a PSU--just not worth it for a 480/'pre HD Ready' set!
-TELEFIX
How PLASMA SCREENS WORK, X-SUS and Y-SUS what they do--
http://www.irf.com/technical-info/appnotes/an-1088.pdf
PLEASE DO NOT EMAIL ME PRIVATELY FOR REPAIR ADVICE. QUESTIONS BELONG ON THE FORUM!Comment
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Re: lg 42" plasma, usp440m-42lp psu problem
yeah i realise it not really worth it , but hate being defeated haha, in any case its been a good learning experince trying to work out the fault, thanksComment
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I have an LG Plasma TV 60PM6700 for the past ~12 years.
In the last ~3-4 months I have been having some issues.- Problem: It started with random picture disappearing (sound still worked).
Frequency: Happened about once a week.
Solution: Had to turn off TV wait a few seconds before turning it on again. - Problem: Then it got worse and the TV started to shut down and when turning on the no picture just sound.
Frequency: Happened about once a week.
Solution: Had to turn off TV wait about 10-20 seconds and turn it on again to solve. - Problem: TV shuts down
- Problem: It started with random picture disappearing (sound still worked).
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Hi Folks
I'm looking for a extreme high current short killer solution for a reasonable cost.
I have an LGA1700 motherboard (ASUS PRIME Z790-P WiFi) where I exchanged the LGA socket already 3 times, and every time after the socket exchange I get a short of power supply lines VCORE (V variable) and VCCIN_AUX (1.8V).
After taking off the socket, the shorts dissappear again.
The soldermask on the socket is already partially demaged from the heat, so I have reconstructed the soldermask by manually painting the missing soldermask parts with a very small top of a...10-15-2024, 10:13 AM -
LCR T7 tester problem short( dz2---v05 )
you changed v05 working now Not a fixed measurement
Any measurement out 2.95v
Kim can solve the problem out 2.95v
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hello,
I hope someone on this forum can assist me.
I have a panasonic TH-42PC77U plasma television.
the lower 1/2 of the screen has become flaky....in and out, then finally goes black and you can only see the top portion.
i have performed the reset to default settings quite a few times. Panasonic recommended..did not believe this would help...it didn't.
I have removed the back panel and looked around for something obvious...burn marks in a board, etc....nothing obvious...
I have read some posts that suggest the problem is related to the boards on the left... -
I check PPBUS_AON and there is a short present on the line, the computer shows a short when testing for short to ground, so when I inject voltage into the line, I get 0AMPS so no short is showing up. I have replaced a blown cap on this board that exploded and tested for the short and it is now removed. Any suggestions? I tested voltage at the line when the fuses are connected and I am getting 1.2 Volts at the line.
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