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The screen works/doesn't.
Posted: Wed Aug 30, 2017 10:16 pm
by Abran920
The day before yesterday I dropped my Minty Pi
. I tried to turn it on but the screen wasn't showing.
The pi light was flashing green and the back-light of the screen was on but no display. I opened it up and checked continuity on everything, and unplugged, realigned, and checked the screen and cables. After that I powered it up and it still wouldn't show the screen. I pulled out the mini HDMI and it showed on my TV. I turned it off and back on and the screen showed up. Nice. I put it all back together and it worked! Now, I dropped it again and the same thing happened ,except this time the screen only works when the HDMI is plugged in when i power on the pi. plz help
Re: The screen works/doesn't.
Posted: Wed Aug 30, 2017 11:23 pm
by Lphillimore
Abran920 wrote: ↑Wed Aug 30, 2017 10:16 pm
The day before yesterday I dropped my Minty Pi
. I tried to turn it on but the screen wasn't showing.
The pi light was flashing green and the back-light of the screen was on but no display. I opened it up and checked continuity on everything, and unplugged, realigned, and checked the screen and cables. After that I powered it up and it still wouldn't show the screen. I pulled out the mini HDMI and it showed on my TV. I turned it off and back on and the screen showed up. Nice. I put it all back together and it worked! Now, I dropped it again and the same thing happened ,except this time the screen only works when the HDMI is plugged in when i power on the pi. plz help
First tip, stop dropping it
On a serious note, you're just going to have to open it all up again, test continuity, ribbon connections etc and hope it's OK.
Check nothing is rattling around inside as its possible you lost a component. If your pi is working with HDMI out however, it sounds like it's OK. If you have another screen to test, test it
Re: The screen works/doesn't.
Posted: Wed Aug 30, 2017 11:32 pm
by Helder
Also if the GPIO connections weren't super solid one could've broken and need a resolder, but likely needs a realignment.
Re: The screen works/doesn't.
Posted: Thu Aug 31, 2017 11:02 pm
by Abran920
All GPIO connections are good but the from the test pads to the screen only VCC and SCK show up as connected on my multi meter. The HDMI output still works and everything else is solid. Does this mean I need a new ribbon or screen, or both. Also if it's a new ribbon cable I need where could I purchase it. Thanks for the help @Helder and @Lphillmore.
Re: The screen works/doesn't.
Posted: Thu Aug 31, 2017 11:55 pm
by Helder
So from the GPIO to the test pads you get continuity? If so then from test pads under the 8pin connector to the LCD test pads you have continuity?
I doubt the ribbon is bad but it's easy to check it with a continuity test.
Re: The screen works/doesn't.
Posted: Sat Sep 02, 2017 1:52 pm
by Abran920
Helder wrote: ↑Thu Aug 31, 2017 11:55 pm
So from the GPIO to the test pads you get continuity? If so then from test pads under the 8pin connector to the LCD test pads you have continuity?
I doubt the ribbon is bad but it's easy to check it with a continuity test.
I tested continuity from the test pads to the 8 pin connector and they all checked out. I then proceeded to test continuity on the ribbon cable and 1 of the 8 pins worked. I don't think I have a way to see if the screen still works but is there a place I could purchase the ribbon cable?
Re: The screen works/doesn't.
Posted: Sat Sep 02, 2017 8:48 pm
by Helder
I have some extra ribbons left over, but how are you testing continuity? You're supposed to remove the ribbon and test continuity on the same pin but on each end of the ribbon, is that how you're testing it?
Re: The screen works/doesn't.
Posted: Sun Sep 03, 2017 3:28 pm
by Abran920
Helder wrote: ↑Sat Sep 02, 2017 8:48 pm
I have some extra ribbons left over, but how are you testing continuity? You're supposed to remove the ribbon and test continuity on the same pin but on each end of the ribbon, is that how you're testing it?
First I tested continuity from the 8 pin connector to the other with the ribbon connector securely in on each side. Then I took out the ribbon connector and tested that from pin to pin. Only one pin had continuity.
Re: The screen works/doesn't.
Posted: Sun Sep 03, 2017 9:33 pm
by Helder
The ribbon itself the white ribbon with blue ends is what you tested? sounds like you're testing the ribbon connectors which can be tested using those test pads on the 2 pcbs with the white ribbon connected.
Re: The screen works/doesn't.
Posted: Mon Sep 04, 2017 12:19 am
by Abran920
Helder wrote: ↑Sun Sep 03, 2017 9:33 pm
The ribbon itself the white ribbon with blue ends is what you tested? sounds like you're testing the ribbon connectors which can be tested using those test pads on the 2 pcbs with the white ribbon connected.
This is how I tested it second. I think I just need a new ribbon cable.
I needed a hand to take the photo
.
