Re: Toshiba LED TV, blank screen
oops - they are 46 inch, not 40.
Telefixer
Member
Last Activity: 03-17-2024, 11:53 PM
Joined: 03-10-2015
Location: Auckland
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Re: Toshiba LED TV, blank screen
Yep, that was interesting reading! I have a couple of 40 inch Toshiba HL900 sets, with the Logo appearing VERY briefly, and then no backlight but the display still working in the dark. Did some testing on the driver board, not convinced it was faulty. Backlight LEDS appeared okay. Also a Toshiba agent, however info is sparse. I then found these threads, and disconnected pin14 of the LED driver board, it's a 14 pin plug, and hello both sets work
faultlessly. Yes, there should be a reason the device driving the ext dim line isn't working, but...
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Re: TH-P42VT30 - 6 blinks
Thanks TW2005 - Replaced IC502, as pin 7 (output) weas shorted. Checked Q531 that it drives, lifting two legs, and it measured okay. Resistors measured okay, but I might just replace the double transistor Q531 anyway.
The transistors I replaced were the normal Q401 etc and Q421 etc IGBTs.
I note that usually there's only one or two of these IGBTs shorted, but I think it's a good idea to replace them as a set, 'cos you don't know how close they got to going also.
syaoran123 - Good stuff there two thanks, I'll check out the extra...Leave a comment:
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TH-P42VT30 - 6 blinks
Hi All.
I've got a 42ST30Z. It's a New Zealand model. When I first got it, it was dead. I replaced the mains fuse and two chopper transistors on the P board. As the SN board was shorted, I found dead IGBTs so I did the normal check for a burnt screen and damaged buffer boards before I then changed the usual IGBTs and their diodes. Turned it on, and hello 6 flashes, 8 if I disconnect the flat control cable SN20.
Very pleased with myself when I found one of the little driver ICs, IC501 and 502, had a shorted output. Replaced them, still 6 blinks!
(SN board is SC plus... -
Re: Panasonic Plasma TH-P42V20A - 1 blink
Well that's all good reading!
I have a 50V10Z, one-blinker. But it will occasionally start up, so I;m thinking it's not corrupted data, as an EEPROM won't fix itself!
Any ideas?
Guys I've also got a 42ST30Z. I'll start another thread, it's gone from 7 blinks (Changed the normal IGBTs and their diodes and the little driver ICs) and now it's 6 blinks, 8 if I disconnect the SC control cable SN20. (SN board is SC plus SD and SU on one board)Leave a comment:
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Re: Panasonic TC-P42S30
Hello TW - great info I must say. I'll be talking to my local Panasonic engineer about these, and how to get hold of them. I have found a dodgy switching driver IC - if it fixes, I'll post the results
IanLeave a comment:
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Re: How To Repair Led Backlight Strips Video !
And - of course - I wonder if most of the reason they fail is cos they can't quite get their heat out through the metal rear. heat sinking - Hot gluing them around teh OUTSIDE of the mini strips so the rear keeps metal-to-metal contact would be a good idea I reckon.Leave a comment:
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Re: How To Repair Led Backlight Strips Video !
Just got back to this - thanks for the interest! Flocko - simple and brilliant. I'd started to remove a lens, but hey that's the last one!
I ended up measuring the current going through one of the 4 strings (series LEDS hence 50-odd volts) and I got 150mA. And I think that was about 75% duty cycle. A 46" not-high end Samsung. So, I think allowing for 400mA would be sensibill.
I guess a very important key, is using LEDS from a reliable model. No point putting in LEDs from a Vestel or similar into...Leave a comment:
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Re: How To Repair Led Backlight Strips Video !
Hi Reecy
Great video mate, with or without popcorn!
I'm just doing this to a couple of sets, Samsung and a Toshiba.
Did you happen to measure the LED current draw at all?
I see Shopjimmy is inaccessible from this part of the world too...
Cheers
IanLeave a comment:
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Re: Loewe Xelos A 37 black screen/no sound.
Hi there
Did you fix this? I've got one to work on now, shuts down after a short while. Loewe TVs drive me nuts.Leave a comment:
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Re: New Members - please post your introductions here
Well hello all, glad to be part of a pretty good site with humour also in it!
My wife and I bought a repair company 5 years ago, which had been running for 40+ years, they even made (assembled) CRT tubes for a while. Have things changed or what.
We're in New Zealand, Auckland, and enjoying the success our rugby and cricket teams are having.
My first career path was 20 years in defence, as I read elsewhere in their intros, I also to some degree am a jack of all trades, master of none!...Leave a comment:
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