Hannspree T280H RGBW screens and no response from remote when hot

[2many]

I was lucky and just fixed my 50" Toshiba with just an ohmmeter, no schematics. I replaced 2 Schottky diodes and 1 Mosfet that was shorted on the PS board and that fixed it. I don't think I'll be as lucky on this Hannspree T290H. When the set is on for approx 1/2 hour or more, the set cuts out. How long it takes is dependent on how hot the weather is, hotter the day faster the problem occurs. In the winter months, it does not occur.

The problem is as the set gets to a certain temperature, video and sound stops, the screen would cycle between red, blue, green, white at approx 2 Hz rate, remote stops working. The only way to reset it is to cycle power to the set by unplugging the AC cord.

I even cut out most of the plastic grills on top and bottom of the set to give it better ventilation, it helps a little and the set runs a little longer before it cuts out. I tried putting a small fan on the bottom of the air intake to force air through it and the set runs 45 min instead of 30 min before the problem occurs.

What do you think it is? PS board? Main board, T Con board?

What does a T Con board stand for and why is it called that? I have not taken it apart yet to investigate. I am new to working on LED TV's but do have some electronics background.

[dick_barton]

Re: Hannspree T280H RGBW screens and no response from remote when hot

That sound like EEprom failure.
Heat and cool the EEprom and see the effects.

TCON - Timing Controller

Take a look and see if there is an update to the firmware which may help
http://www.hannspree.com/US/EN/SoftwareUpdate.aspx

[2many]

Re: Hannspree T280H RGBW screens and no response from remote when hot

It's hard to access the main and PS board since they are both mounted in a metal enclosure. Cutting away the top and bottom of the enclosure to get more air flow was not enough to stop it from cutting out when it gets hot (less than 30 min). When running without the metal enclosure, it does not cut out. The enclosure is needed to mount the boards, can't just toss it. I ended up cutting 2 big openings on the back of the enclosure with tin snips. The masking tape covers up the sharp edges which was too much work to grind smooth. The set works now without cutting out anymore.