a20 with LCD screen problem

[jonnydedwards]

Hi All,
I'm a bit of a newbie ... trying to get the 10.1 tft touchscreen installed with my a20 - I've enabled the LCD screen (using the script in /root) and connected the necessary wires (do I need to power it separately?)on boot the screen flashes and immediately the a20 stops working (green light switches off). Anybody got any advice on how to fix this ?
thanks in advance,
Jonny

[rouvas]

All I can say is that I had no problems with mine.
LCD powered directly from board.

[dave-at-axon]

This sounds very much like a power issue. When it flashes like that it usually means the backlight came on and then power dropped too low to keep the CPU working.

What power supply do you have? ie,how much current is it capable of and what voltage?

[MBR]

Yes, it's very probably a power issue, I got similar behavior when running on a battery-fed step-up convertor. If you turn the LCD on with PWM set to 100%, the inrush current is larger than nominal and the power source cannot handle it. If you want to use the current power source, you must start with the PWM at 0%, then enable the LCD and after that you can increase the PWM slowly up to 100% (on my configuration, "slowly" is about one second). This approach removes the large inrush current when turning the LCD on and if you use some kind of splash screen, the gradual lightning up of the screen also looks quite cool

[jonnydedwards]

Yep - power problems - thanks very much for all the help here - much appreciated
Jonny Edwards