Mulja tv repair portal
Equipment Repairs => LCD TV forum => Topic started by: Turnip on February 23, 2018,05:26:37
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Hi folks,
Set uses single board TP.SIS231.P83. Out of standby the Green Led glows and the backlight fires up giving a dull Blue screen. Set cuts to Red Led S/by then cycles back to Green Led where it has another go at firing up. Eventually, after a variable time (seemingly not temperature dependent) the set fires up and works normally for hours, other times it cuts to S/by within minutes.
Gather it's a common problem with UMC sets, as had two in the past where I replaced Eeproms to no good effect and they ended up on the pile. Gather some folks think it's a M/proc issue but it doesn't seem heat sensitive as I would have thought - Any thoughts ? - Chris.
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Freeze EEPROM on main board (TPSIS231P83), save its contents to a dump file, replace EEPROM with a new memory chip and reprogram it with the previously saved content.
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Thanks Jordan,
Think mentioned I've replaced the Eeproms, after buying a couple where it made no difference whatever. Folks selling Eeproms suggest not using if the set displays backlight cycling, suspecting the M/proc duff. Cost me £50 for the first try with two Eeproms - Bins uploaded to Quuq in case useful.
Feel that Eeprom corruption should be permanent, but latest set comes on when it feels like it, and maybe stays on all day, or not.
Suspect UMC sets are total crap, but hope to be proved wrong as they seem energy efficient, even when they work - Chris.
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@Turnip
Suspect UMC sets are total crap, but hope to be proved wrong as they seem energy efficient, even when they work - Chris.
Here, here, always eprom problem with these sets. Problem I find is getting the right dump. I've got two now with ADC fail and eprom data missing - one of these days I'll pop a blank eprom in and try to install firmware, both of em' won't let me. Funny thing is there's no tuning but yet the set works ok.... one of them had a cracked ccfl, my guess was the arcing.
When trying to install firmware it puts a empty folder on the stick.
One good thing I'd say these sets love being converted to LEDs, to me the piccy seems more crispy.
Dave
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Nice one Dave,
Not yet seen much of a picture. Followed Jordan's advice, clipped the Eeprom and saved to a file. Blanked Eeprom and loaded saved file. Set still doesn't fire up but the Blue S/by Led flashes differently, and now no picture, even after hours of cycling.
Not met one with CCFLs, guess they were better than the current single board models, as each and every one has the same cycling issue, not one resolved though spent a fortune on Eeproms - Chris.
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Have you checked the on-board dc-dc voltage converters? I scope em' as well for hash.
Dave
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Thanks Dave,
Haven't so far as suspect sets just a year plus old shouldn't have such issues, and caps look pristine. Mind you, service data would be handy, but seen nothing for any UMC set, and most seem to have the same issue where Eeprom updates simply cost cash, and get no-where, as set cycles endlessly.
Note that an Eeprom supplier suggested 'Cycling' indicates a M'proc issue, and best bin the set. Trouble is that there are so many, as folks love cheap sets - Chris.