Thread: Ah! My LCD won't work

Just tested my VGA->Controller cable and it works fine with no shorts or anything so the problem must be elsewhere..

jason

Ok some more info..

This same setup used to work with my ghetto cable I made at home (hirose) but then I can't test it with that anyy more because half the pins became unsoldered. Could either the enable or the sync's on the LCD or controller be messed up? How can I test this?

Also, the hirose cable I have now is meant for the LQ9D161 and my LCD is a LQ9D03B.. All the pin outs are the same except for pin 18! On this cable, 18 is NC (because it is a TEST pin on the LQ9D161) but on mine it should be ground.. Could this be the problem? Does the LCD tie all the GND's together or does it use each one individually?

Also, I think I fed reverse polarity to the ruble controller for about 10 seconds.. However, everything on it seems to work still (output voltages, the one frame is clear and looks exactly like ti should, etc.).. Hopefully I didn't screw up the controller!

Jason

I did some testing with my multimeter and found:

- The Vcc lines have 5 volts initially, but as soon as I put my multimeter to them, it starts dropping toward 0

- Even after the Vcc lines drop to 0, the CLK line still shows ~2.35 on my multimeter (this is what it should be right? Since it keeps oscillating between 0 and 5?)

- The ENAB has +5 volts, I think even after Vcc drops to 0


If I plug in my LCD and then disconnect the power from it, the same effects are present as if I just leave the power connected.. This is telling me that the cause of the problem is the Vcc lines dropping to 0..

Do any of you know why these lines are not remaining +5? Could a cap or something similar be bad?

Thanks!

Jason

TTT... anyone have any clue what components coudl be bad?

Thanks
Jason

Dude,
Sorry I couldn't get back to you sooner. Are you still having problems with your LCD?

Here's some of my experience.

Using the LQ9D161 and the RUble controller, I accidently hooked up the cable backwards and was getting wierd behavior on the LCD and then it blew out the controller for good. The LCD was OK.

Sounds like you're still getting a picture than a fade to black.

Regarding connecting pin 18 to ground, generally, ground is ground so you should be able to jumper the pin 18 on the LCD to another ground on the same connector and basically get the same result. Now I'm not an expert so please check it out before you do anything. I don't want you to blow out you LCD or controller if they both work.

I'm not sure I can help you much more. Shoot me an email. maybe we can discuss it that way.

Pigseye

pigseye, I hooked up the pin to ground, and still the same problems.. do you still have the LCD controller you blew out?

arby, doh that bites! what problems were you having? weird thing is, my controller still outputs regulated voltages and shows the first frame, but then the voltage drops to 0 on most of the lines (except ENAB and CLK). I'll look mroe into this over the weekend. I really hope I didnt fry it, as these controllers are frigging hard as hell to come by! do you still have your controller too?

Thanks
Jason

Hey Red,
Yeah I still got the controller. When I get a chance I'm going to ask a techy friend of mine at work to look at it. He may be able to fix it.

Are you sure your LCD is OK? I've got an LCD that appears to be fine but I have lost all the LSBs for the color red. All red pixels are at full brightness. My friend saw it and said it's not rare to have that kind of failure in the LCD itself. Got another LCD and used the same controller/cable and it looks great. Just another thing for you to check.

Sorry you're having so many problems.

Good luck man
Pigseye