GBZ White Screen - Gearbest screen

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retrov
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GBZ White Screen - Gearbest screen

Post by retrov » Thu Oct 11, 2018 7:50 pm

The screen works. I tested it before starting my build by just connecting it to the pi. It looked flawless. However, after connecting it to the PCB, I'm now just getting a sometimes flickering white screen while testing it.

Image

Here's my wiring.

Image
Image

Any ideas? The tubing on the screen's yellow wire is there because I accidentally nicked the insulation with the soldering iron, and I covered it as a precaution.

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VeteranGamer
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Re: GBZ White Screen - Gearbest screen

Post by VeteranGamer » Fri Oct 12, 2018 2:24 am

check there isnt anything touching causing a short....

but more so...
check that your ribbon cable is properly seated/connected to the board (ribbon cable of the LCD)


worst case scenario...
check that there aren't any rips or tears in the cable...
this could have been caused when installing/gluing in the LCD


also is the Pi Zero actually turning on, and running as normal....
(quick check, by connecting to a HDMI screen)



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retrov
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Re: GBZ White Screen - Gearbest screen

Post by retrov » Fri Oct 12, 2018 12:58 pm

Thanks for your help, VeteranGamer. The ribbon cable is properly seated, and I couldn't see any visible rips or tears in it. I connected the Pi Zero to a TV, and everything worked okay. Is it possible I damaged the yellow wire enough that when I touched it with the soldering iron that it could cause this? Can the video wire be repaired via splice, or is it imperative that it's a uniform solid cable? I have extra 4 prong jst connectors. Maybe I should just replace the provided screen cable with one of those...?

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Re: GBZ White Screen - Gearbest screen

Post by VeteranGamer » Fri Oct 12, 2018 1:33 pm

retrov wrote:
Fri Oct 12, 2018 12:58 pm
Thanks for your help, VeteranGamer. The ribbon cable is properly seated, and I couldn't see any visible rips or tears in it. I connected the Pi Zero to a TV, and everything worked okay. Is it possible I damaged the yellow wire enough that when I touched it with the soldering iron that it could cause this? Can the video wire be repaired via splice, or is it imperative that it's a uniform solid cable? I have extra 4 prong jst connectors. Maybe I should just replace the provided screen cable with one of those...?

having a splice really shouldn't cause critical issues, but having a good connection is more vital...
(changing the wire could be a fix)

i personally don't use the wires that come with the Gearbest screen....
(they just seem a little thin, especially as the Red wire is meant to carry 12V)

but i still use the JST connector....
i swap out the Ground and the AV (Yellow or White) wires and use my own....


i actually use an old AV cable for my connections
AV & Ground connected to Pi Zero
and
AV & Ground connected to the Screens board
(this is a extra Ground, connector to/wiith the Ground for the Power)

shielded AV cable used...
(inner core = AV outer core = ground)

Image



i also dont wire my 5V via the connector

i have it here (with a good gauge wire), its a better connection (IMO)

Image



some people just remove the JST connector all together and wire straight to the points....

personally i wouldn't recommend that, as from my own experiences you can easily mess it up...
(maybe not even your own fault, but just because of poor solder points on the board)
the solder points could rip or burn and then your left with a near unusable board.....





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retrov
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Re: GBZ White Screen - Gearbest screen

Post by retrov » Sat Oct 13, 2018 8:28 pm

An update - After changing wires, trying a different jst connector, lo an behold there was a tear in the ribbon cable after all. It was a super tiny one right near the end of the cable at the screen. Very frustrating.

Thank you for all your help, VeteranGamer. I'm going to get a replacement screen and take another crack at it.

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KonnorJ
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Re: GBZ White Screen - Gearbest screen

Post by KonnorJ » Sun Oct 14, 2018 6:07 am

To check for ribbon cable damage shine a light behind it, incredibly easy to spot any breaks in the traces this way

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xxrob511
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Re: GBZ White Screen - Gearbest screen

Post by xxrob511 » Tue Oct 30, 2018 12:58 am

VeteranGamer wrote:
Fri Oct 12, 2018 1:33 pm
retrov wrote:
Fri Oct 12, 2018 12:58 pm
Thanks for your help, VeteranGamer. The ribbon cable is properly seated, and I couldn't see any visible rips or tears in it. I connected the Pi Zero to a TV, and everything worked okay. Is it possible I damaged the yellow wire enough that when I touched it with the soldering iron that it could cause this? Can the video wire be repaired via splice, or is it imperative that it's a uniform solid cable? I have extra 4 prong jst connectors. Maybe I should just replace the provided screen cable with one of those...?

having a splice really shouldn't cause critical issues, but having a good connection is more vital...
(changing the wire could be a fix)

i personally don't use the wires that come with the Gearbest screen....
(they just seem a little thin, especially as the Red wire is meant to carry 12V)

but i still use the JST connector....
i swap out the Ground and the AV (Yellow or White) wires and use my own....


i actually use an old AV cable for my connections
AV & Ground connected to Pi Zero
and
AV & Ground connected to the Screens board
(this is a extra Ground, connector to/wiith the Ground for the Power)

shielded AV cable used...
(inner core = AV outer core = ground)

Image



i also dont wire my 5V via the connector

i have it here (with a good gauge wire), its a better connection (IMO)

Image



some people just remove the JST connector all together and wire straight to the points....

personally i wouldn't recommend that, as from my own experiences you can easily mess it up...
(maybe not even your own fault, but just because of poor solder points on the board)
the solder points could rip or burn and then your left with a near unusable board.....





.
Do you replace the cable completely and swap the cable on the JST connector. or do you just cut the cable from the gearbest and then add your own cable onto the end of it?

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