I can't figure out how to power up my screen...HELP

diy_guy · Post by **diy_guy** » Tue Jan 08, 2008 12:18 pm

LTS500Q1 (same as PS1) screen with AN2546FH-A controller IC I have the datasheets for the screen and controller. I believe my screen is either composite or component input. I've tried 3v 5v and 7.5v but can only seem to darken the screen, I replaced the backlight with a small led but that wont power up either without direct power. My power source I'm testoing is a 9v battery with a variable resistor that I can dial to the power I need checking it with my meter.

Valium · Post by **Valium** » Tue Jan 08, 2008 1:49 pm

A 9 volt battery doesn't have the amperage needed to run the screen, I know the rechargeable 9 volts have about 200 mAh, which is almost a third of the required amperage.

diy_guy · Post by **diy_guy** » Tue Jan 08, 2008 6:44 pm

I just picked up a 8 AA battery pack which can give me up to 12V, which I'll run through a 100Kohm Pot. Though I'm not sure how many Amp that is, I'm assuming it's more than 1amp. Approximately how many amps does it take to run a 7" TFT LCD?

Valium · Post by **Valium** » Tue Jan 08, 2008 6:51 pm

You really only need 7.5 volts.

Turbo Tax 1.0 · Post by **Turbo Tax 1.0** » Tue Jan 08, 2008 6:58 pm

don't run it off of 12 volts without a voltage regulator

you only need ~7.2

diy_guy · Post by **diy_guy** » Tue Jan 08, 2008 8:07 pm

Yeah, I couldn't reduce the power after all, it kept blowin fuses in my multimeter and blew out 2 potentionmeters. I took 3 AA ou tof the pack and that should be ~7.5V with a little mod to complete the pack circuit. I have the origional 7.4V 2200mAh LiPo battery pack for it but I don't have a way to charge it.

With the 7.5V AA battery pack I probed around with the same results as before, the screen just darkens when probed from main ground to several contact points on the IC and board.
I can't find where the backlight power comes from, that part of the board seems completely separate from the rest save for what looks to be 3 strips sandwiched inside the board that I can't get at nor tell where they go.

I know I've still gotta be doin something wrong somewhere but it's getting very irritating.