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BW Variant Screen Problems
Posted: Sat Jan 28, 2017 11:54 am
by RetroTeacher
Ok, so my first build I was using a gear best screen, got everything and mostly fully working, but damaged my screens ribbon. So had to chuck that, and ordered a BW screen off amazon. I have tried a 5v conversion I found and the screen turns on, shows a test pattern and AV1 in the corner, but then goes white and static. In addition the powerboost shows a low battery light, assuming the screen is draining more than 5v. Any help?

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Re: BW Variant Screen Problems
Posted: Sun Jan 29, 2017 12:33 am
by Hex
Firstly the pin might be incorrect. It is 3rd pin on most ICs (eg BM141a)
Secondly the ground doesnt need to be connected, so you don't need the short black wire. You basically need a short/wire from 5v input and the output of the regulator (that's your small red wire). Make these changes and it should work. There might be a short between your 5v and Gnd, the soldering looks bad. Do that again. You can remove the yellow wire.
The connections are as such
Red +5v
Black GND
White Channel 1
Yellow Channel 2
At present it seems you are connecting White and Yellow to the Pi's composite out, which is wrong. You should need only three wires going into the display (Red, Black, White).
Re: BW Variant Screen Problems
Posted: Sun Jan 29, 2017 9:34 am
by RetroTeacher
Thanks for the reply! Tried your recommendations, moved the red wire up a pin so it was in position 3, removed the ground wire going from pin to ground, removed the white wire (never had it hooked up to pi, was just still on screen board), still getting too much power draw from the screen. Desoldered all the connections at the end of the board and cleaned up with flux and wire braid and made sure there was no short (I was sloppy the first time) and checked with voltmeter to be sure. Forgot to mention the first time but it also makes my speaker whine when powered on. Ended up ordering a new screen from gearbest (should have done that in the first place since I was able to get that one working easily).
It's the last thing I need

Have the rest working perfectly when hooked up to an hdmi monitor! Can't wait to show this thing off to my high school students!
Re: BW Variant Screen Problems
Posted: Sun Jan 29, 2017 12:21 pm
by Hex
Can you show me the wiring of the other parts of the Gameboy Zero. Show me how you have connected the screen to the pi.