Author Topic: UMC Back light issues.  (Read 270 times)

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Turnip

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UMC Back light issues.
« on: April 28, 2018,10:33:06 »
Hi folks,

Have had several where the back light cycles on and off.

As crap sets have chucked them on the recycling heap, not bothering to check screen Leds as they seem such rubbish often with a single board which does everything 'till the guarantee runs out.

Wonder if anyone has sorted one - Chris.

Mulja tv repair portal

UMC Back light issues.
« on: April 28, 2018,10:33:06 »

astracat

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Re: UMC Back light issues.
« Reply #1 on: April 29, 2018,14:57:54 »
hi turnip
had an early one which couldnt cope with screen refresh when signal changed to accomadate hd transmissions screen blanked on/off every few minutes but
no sftware update to try hence it ended up on proverbial tip.eve hd box came up with resolution not supported
regards
astracat
« Last Edit: April 29, 2018,15:04:42 by astracat »

downunder

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Re: UMC Back light issues.
« Reply #2 on: April 29, 2018,18:15:36 »

Have had several cheapie LCDs where the panel has plastic backing (not metal). They become very erratic - blanking out, los of signal,
glitching etc. The fix was to lift the pcbs, cover the panel backside with al. foil and reassemble. Appears to work as I've done quite a few.
My unproved theory is that the panels emit a lot of garbage as they age and this trips up the eeprom.                 Bruce

Mulja tv repair portal

Re: UMC Back light issues.
« Reply #2 on: April 29, 2018,18:15:36 »

Turnip

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Re: UMC Back light issues.
« Reply #3 on: April 30, 2018,11:50:07 »
Hi 'Cat' and Bruce,

Note plastic back-light panels tend catch fire at the least.

Thinking of the issue where UMC sets cycle back lights on and off and an Eeprom doesn't sort it. Folks supplying the Eeprom suggest 'cycling' is a M'Proc issue.

Might just be duff screen Leds, but as UMC sets are so cheap haven't tried taking the screen apart to find out. as a new set is cheaper.

 

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