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Equipment Repairs => LCD TV forum => Topic started by: dynomo on February 20, 2013,17:03:38

Title: Evotel ELCD40USBFHD
Post by: dynomo on February 20, 2013,17:03:38
Got an Evotel in for repair? Never heard of them anyway model number is ELCD40USBFHD.

Colours on this set are all over the place and blocky. Customer has already changed T-con. I think the AV panel is the issue. Anyone had any dealing with this brand? PSU voltages all look fine. I noticed for first 10 minutes picture was fine then the colours gradually go strange, screen brightness increases and also noticed flickering all across the picture. Supply is nice and stable. Sounds like maybe a cap is faulty from first impressions. Cannot find any info on the set . Watching someones face on the set makes it look like they are bleeding from the eyes .  :sign0085:
Title: Re: Evotel ELCD40USBFHD
Post by: jordan on February 21, 2013,02:07:01
http://shop.sjstv.co.uk/tsp91001d-2494-p.asp
Title: Re: Evotel ELCD40USBFHD
Post by: dynomo on February 21, 2013,02:47:23
http://shop.sjstv.co.uk/tsp91001d-2494-p.asp

Thanks Jordan. Do you suspect same as me this board is faulty?
Title: Re: Evotel ELCD40USBFHD
Post by: dynomo on February 21, 2013,04:45:17
Been looking at this set a bit more this morning. Looked so much like a faulty t-con I thought I had better have a closer look. Customer tells me he replaced the t-con but same fault remained after replacing. I have let the fault really kick in for an hour on the bench here and then used my good old freeze spray on the t-con board and fault clears. Picture, brightness and colour go back to normal. Customer probably fitted another faulty t-con.  :s_laugh:  :sign0081:

Title: Re: Evotel ELCD40USBFHD
Post by: dynomo on February 21, 2013,05:46:02
After some freezing and heating I located the fault to a small LCD buffer quad pack ic on the t-con board. Any heat near it and the picture went nuts and backlight flickered around. Put the board under the microscope and found a short between 2 legs on the chip and several other small loose bits of soldered around this IC in another location. I removed the chip and cleaned it up and put it back and the fault has cleared. Must of been a tiny bit of heat was expanding the joints just enough to cause a short or enough resistance which caused the picture to go bad. Interesting fault. :sign0098: