Author Topic: UMC TP SIS231 PTXXX Boards.  (Read 394 times)

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Turnip

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UMC TP SIS231 PTXXX Boards.
« on: July 30, 2017,09:25:43 »
Hi folks,

Had a couple in recently, marvelling how so much could be accomplished on a board 6 inches square - Power, SSB, Sound, Inverter.

Turned them on - 32 and 39 inch sets to find they were both sort'a stuck either in S/by or with 'Maker's' OSG which cycled off and on again every 30 seconds or so.

First time around I suspected Eeprom so got expensive replacement and fitted it - Same - Don't think bother with the other one, as not now a UMC single board fan.

Wonder how other folks find 'em - Chris.

Mulja tv repair portal

UMC TP SIS231 PTXXX Boards.
« on: July 30, 2017,09:25:43 »

downunder

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #1 on: July 30, 2017,19:34:19 »

Hi Chris,

Cheap and cheaper - but seem to be the rage at the moment. Don't like them at all as they are virtually unserviceable, which is probably what the manufacturers

want - and fewer parts to keep in stock for a shorter duration. What devious plan will they come up with next?  -  Bruce

Turnip

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #2 on: July 31, 2017,11:30:10 »
Hi Bruce,

Thought as much. Going for the Eeprom, suppliers stated 'If the backlight is cycling don't replace the Eeprom as the CPU will kill it'

Being careful, reprogrammed the original from the replacement to find that instead of being stuck in S/by, backlight came up and cycled on and off every 30 seconds. Undaunted I loaded a blank Eeprom with new data - fitted it and got the same outcome.

Haven't yet tried 'cooking' the boards, as seems no other option but 'Oil Drum Row'

My second set also had the 30 second backlight cycling, and they're both maybe a couple of years old - Give me Vestel any day - Chris.

Mulja tv repair portal

Re: UMC TP SIS231 PTXXX Boards.
« Reply #2 on: July 31, 2017,11:30:10 »

downunder

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #3 on: August 01, 2017,03:23:02 »

Hi Chris,

This TV doesn't perchance have a plastic-backed panel.               Bruce

Turnip

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #4 on: August 01, 2017,11:43:21 »
Hi Bruce,

In some ways it's rather nifty where the rear of the screen is Blackened metal and also the back of the set. The 'everything panel' fits in a plastic box at the bottom which also contains some rather small speakers. Another plastic box houses the DVD player, keeping it mostly free from dust which could be useful if the set lasted much longer than the year's guarantee.

Remember a while ago buying a full set of Led strings (before LG Leds were 10p each) where the back panel was Black plastic - Gather Black is quite good dissipating heat before it catches fire.

As you say - Hate to think what's next up the sleeve of our Chinese brothers - Chris.

bonesy

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #5 on: August 02, 2017,06:49:20 »
Has anyone seen or repaired any of the Hisense range of TV's,I've not seen one yet,but  a lot of advertising on their products now. I've scrapped off a few of the one board wonders,very poor quality,makes Vestel look high end,lol.

Mulja tv repair portal

Re: UMC TP SIS231 PTXXX Boards.
« Reply #5 on: August 02, 2017,06:49:20 »

downunder

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #6 on: August 03, 2017,05:37:20 »

Hi bonesy, it's a faily common el-cheapo brand downunder. Believe they're big on replacing warranty TVs that break down, rather than pay ASCs to fix them. Probably indicative of how much they import them for, which conversely is indicative of the quality.                Bruce

bonesy

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #7 on: August 03, 2017,10:28:45 »
Oh dear,I seem to remember lots of adverts around the time of the Olympics,now ads for 4K sets on TV.

Turnip

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #8 on: August 03, 2017,13:03:49 »
Hi Bonesy,

Just had a 2003 JVC given to me, and it still works perfectly in spite of CCFL's and the two chips mounted in holders. No takers of course as you can get a 55 inch for just over 200 Quid.

Could be wrong assuming a large panel is where the cash goes, but couldn't they at least fit a decent main board ?

Will retire when Vestel comes up with a combo panel - They haven't yet which indicates something or other. Sadly Bruce hasn't yet had the pleasure of Vestel - Chris.

downunder

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #9 on: August 04, 2017,04:38:20 »

Hi Chris,

Sadly I did have the misfortune of servicing some British colour sets in our early days of colour.

There was a Thorn 3504 and a 4KA chassis (that's what they called them here). The 4KA had these horrid thick-film devices and the 3504 was a nightmare.

Then there was a Decca chassis with some valves in it, as well as Tynne sets. Someone forgot to mention that they were designed for cooler climes. Thank god

those days are gone. Now it's cheap China knock-offs.    Bruce

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Re: UMC TP SIS231 PTXXX Boards.
« Reply #10 on: August 04, 2017,11:39:55 »
Hi Bruce,

Sounds like the early 70s. Up 'till then had only dealt with Philips dual standard colour with all those system switches, and Philips VCR with bowden cables and turnover cartridges. We also had Pye sets with double sided print where they used rivets to connect the sides together, also thick film thingies we replaced with lots of W/W resistors in a mare's nest. We also had hybrid GEC which were quite reliable though the pictures were dubious, and early hybrid Bush, one of which burned out a shop so we didn't have any more for some reason.

Then moved to another company where Thorn was the biz with the new 3000/3500 chassis using 'jelly pot' LOPTs. Sets were quite reliable apart from convergence pots and the early S/M power supply where 70v was the max for the line section as they didn't have the transistors to handle more.  Sets had a 'crowbar' to short down the HT if it got wild, also a resettable thermal cut out on the back of the set which was quite effective as caps were all 85c and pooped all the time.

Only met Decca hybrid colour when self employed in 1976 - Dual standard but pretty basic - Never met another, but not too sad as they were pretty heavy, but not quite the weight of the later Toshiba 37 inch flat screen tube jobby - Def the heaviest - Chris.

 

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