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Equipment Repairs => LCD TV forum => Topic started by: Turnip on June 10, 2018,10:42:33

Title: Samsung UE40F5500AK
Post by: Turnip on June 10, 2018,10:42:33
Hi folks,

Got one where backlights work but no picture. Note Bruce suggested IC200(ISL9860) on the T/con might be duff. Thought get some then noticed chip is a multi-contact SMD, so didn't bother although they're quite cheap.

Suspect T/con from smashed screen sets might be dubious guarantee wise considering the price. New panels available but at a price where folks would rather buy a new TV. Looking for a firm who enjoy changing T/con SMD chips - Chris.
Title: Re: Samsung UE40F5500AK
Post by: astracat on June 10, 2018,14:40:54
hi turnip
presume fuse on tcon ok,several vids on utube showing how they change the chip or ohms do a postal fitting .
regards
astracat
Title: Re: Samsung UE40F5500AK
Post by: downunder on June 11, 2018,05:32:13

Hi Chris,

Are there any blue LEDs on the T-Con. Some have 3 LEDs. If all 3 are lit, the T-con is OK. If any of the LEDs are out, though, it could be T-con or panel.                     Bruce
Title: Re: Samsung UE40F5500AK
Post by: Turnip on June 11, 2018,09:28:12
Thanks, Cat and Bruce

Will look for T-con fuse, guess jumped the gun thinking IC200 duff. No lit Leds so guess supply missing. Will take a look on Utube - Curious to see how the chip is replaced - Chris.
Title: Re: Samsung UE40F5500AK
Post by: Turnip on June 12, 2018,11:32:35
Hi folks,

Had a good look, and my RUNTK 5351TP-0055FV doesn't seem to have any Leds. Spent an hour on YouTube where seems every issue but mine was covered in various languages.

Fuse OK - Feeds Q300 which is an NPN 3 pin SMD of some sort, and appears OK resistance wise, but no output voltage though fed with 13v via the fuse. SMD Q300 is marked as C403-312 where I could find nothing. Nearby is a 8 pin SMD chip bearing the legend Y86-0701-308 - Again nothing anywhere.

Note that China does new panels at 30.00 so think go for one. Odd that a Sammy screen uses a Sharp T-con, especially as later Sharp sets tended to use Vestel innards, as had fewer issues - Chris.
Title: Re: Samsung UE40F5500AK
Post by: kennyc on June 12, 2018,13:39:47
Hi Turnip, had a Samsung with no picture cant remember model number but thought T-Con was faulty but it turned out to be one of the small caps on the board below the T-Con. If it has this board there are about 8 in a row and they look like surface mounted fuses . One was leaky . Like I say i cant remember the model number .
Title: Re: Samsung UE40F5500AK
Post by: Turnip on June 13, 2018,11:38:31
Thanks 'Ken'

Disconnected flexies T/con to screen - No difference. Noted that a chap on Youtube checks drive from the SSB using a meter on the T/con input buffer resistors, noting voltages or not. Had voltages, so suspect T/con not turned off due to lack of drive. Also checked for duff ceramic caps - Nope. Did discover that Q300 is controlled by the big chip to the right, but it has no voltage on any pin, and can't see where it's supply should come from - Chris.

Most everyone suggests IC200 is duff, always is if the fuse hasn't popped. 'Microtech' likes to sort them for a modest price.
Title: Re: Samsung UE40F5500AK
Post by: Turnip on June 23, 2018,11:32:43
Sent panel to 'Microtech' where they replaced IC200 - Job done.

Thought to get a few ISL9860 as cheap, and as now have a PCB pre-heater and a hot air gun, will have a go myself.

Guess takes practice to get the new chip to sit exactly where it should and solder it.

It's always easy on YouTube as it works every time - Chris,.