TM-868 backlight

**sphere76** · 02-06-2008, 03:10 PM

Hi!

This might be too stupid question but...

I just bought an used 8" TFT (SGDQ TM-868).
It didn´t have AC/DC adapter so i bought a 12V, 1000mA adapter with + in center.

My problem is that when I turn it on, the screen stays black. I´ve tied almost everything but still..nothing. The power light is red. Shouldn´t it be green anyway?

Thanks
Jari, Finland

**Morpheus2010** · 02-06-2008, 04:07 PM

mine just went out i have a shark 8" screen i bought from gooddeals18 it was working fine and it just went black. The wierd part is that the touchscreen still works when i touch any part of the screen my computer still responds. ie play, pause, next etc etc

**bbalazs** · 02-06-2008, 04:46 PM

That power seems to be quite low.
This type of monitor needs around 10W at normal working. Directly after switching on, the current runs above 2A for a short time (because charging capacitors), and perhaps your adapter is not strong enough to provide this, therefore voltage falls.

Run it from the PC power supply at home or
buy a cheap 12V 3A stabiliser IC (eg. 78T12) instead and drain the car battery (with engine on, of course).

**bbalazs** · 02-06-2008, 04:48 PM

Originally Posted by Morpheus2010

mine just went out i have a shark 8" screen i bought from gooddeals18 it was working fine and it just went black. The wierd part is that the touchscreen still works when i touch any part of the screen my computer still responds. ie play, pause, next etc etc

Perhaps just the backlight is off. Try to enlight it by a strong source of light. Do you see any sign of picture? Use a picture with high contrast.

**Morpheus2010** · 02-08-2008, 06:50 PM

All I see is when i turn it on is a flash and the screen stays black. i've even plugged it up to a ac adapter. The screen was working for a while before this happened. only the touchscreen works now. thanks for the help