MintyPi 3 Screen going all white after booting

[nilus2k]

So I got my MintyPi together and it seemed okay. I checked continuity several times, did start up tests several times before I finally buttoned it up and initially it seemed happy. I charged the battery and was able to load roms on to it.

Then I started running into an issue that evening. It started booting up fine and then the screen would go all white. Buttons and sound would still work but the screen stopped displaying. Closing the case still activated the magnet switch to shutdown as well. At first it didn't seem to happen every time but with more experimenting through the weekend it got so bad that it would boot, show the first Retropi splash screen and then go all white.

So step one was getting it apart again. First step was checking the screen. I reseated the ribbon cable and even reflowed the connector again but the white sceen issue kept happening. Next step I pulled out the main system and formatted the SD card to see if maybe it was a corrupted OS. Still got the white screen.

I am now on to phase 2. I have the main button PCB and Pi out and powered directly from the usb on the Pi and....No White screen. Seems stable. I am putting some roms back on now to test further. So the problem, it seems, is power related. I need some helps with my next steps though on what to check. Here is what I plan

1) remove the power PCB from the tin and reconnect it and see if it works(maybe something is contacting the tin and shorting out?)

2) checking continuity again on the Pi to the PCB.(I did this already but always good to check again. Especially check the 5v stuff since this seems like its power related)

Any other idea or suggestions would be appreciated. My concern is this. When I first put it together it seemed like the USB 3 port was not quite right and if you wiggled the cable it caused contact and a short. It did not seem to cause an permanent damage at the time and it worked after I fixed the port and rebuilt it but now I am wondering if I shorted something out.

[Joeblowv1]

might have something to do with the dualfet on the powerboard that Helder is fixing. You should check his instagram, he is repairing power boards as they are prematurely cutting out, if it will boot with a FULLY charged battery, and then very quickly not boot, that may be the issue?

[LilTrublMakr]

Yes, it is very very likely the dualfet since mine is doing the same thing. Helder is having new boards made and/or replacing the chips by hand and will send people a replacement board for those that sent a kit already.

More info can be found here: https://www.instagram.com/p/BvFTK6OFfga/

It might take a while but Helder is doing all of this in his spare time on top of a job and his family. The PCB fabricators he used messed up on multiple things and Helder is trying to clean up their mess. (Not directed towards you, just making a statement.)

[nilus2k]

Thanks guys, I will reach out to him via email to figure out what he needs for the replacement. Sucks that there is a bigger issue but I am kinda relieved that it was not my mistake.

[Helder]

Yes the dualfet is cutting out once the battery gets to 3.5v to 3.7v and for most people the screen cuts out. Send it back and I'll fix the dualfet and I recommend anyone transferring roms to have it powered off usb so that there is steady power until you have the proper dualfet.

[GoldenPSP]

Hmm,

I figured I would post here rather than starting a new thread. I haven't finished my build yet. I had stopped after getting the pi and headphone jack soldered on to test. I just get a white screen when powering up.



I have checked my connections with the test pads about 7 times. I get connectivity with all of them. I have also checked neighboring pins in case there were issues with shorts across them, both horizontally, vertically and diagonally. I also checked the test pads from the LCD to the test pads on the board and get connectivity with those.

[LilTrublMakr]

Have you flashed the MintyPi image? If you have, I would recommend reflashing it. Also, If you haven't reflowed the ribbon cable on the screen, I would recommend doing that. (See https://www.instagram.com/p/Bu4pEUrF3C5/ and https://www.instagram.com/p/BvDV_2llqbx/)

[GoldenPSP]

Have you flashed the MintyPi image? If you have, I would recommend reflashing it. Also, If you haven't reflowed the ribbon cable on the screen, I would recommend doing that. (See https://www.instagram.com/p/Bu4pEUrF3C5/ and https://www.instagram.com/p/BvDV_2llqbx/)

I've flashed the image onto 2 different cards. I verified by plugging HDMI directly into my monitor.

I have not reflowed the ribbon cable. To be honest I'm still a pretty solid newbie to these kinds of projects. I wasn't sure exactly what I was looking at for the second picture that you posted. I wasn't sure where to find it exactly and i didnt want to just start prying things apart with the screen assembly and risk breaking it.

I see 2 large metal "clips" on each side of the LCD. If I carefully lift those does that separate the component to get to that cable?

[edit]

I saw in that instagram post there is also a video showing the separation. Thanks.

[LilTrublMakr]

You need to pry the screen from the black board. I took a thin guitar pick and slid is across the 3 edges that does not have the ribbon cable and got it off that way. Just take your time.

When reflowing, I would recommend using flux, putting some new solder on the tip every few pins, and carefully going from the pads to the pins. Take your time. It might take a few reflows to get it working.

[GoldenPSP]

You need to pry the screen from the black board. I took a thin guitar pick and slid is across the 3 edges that does not have the ribbon cable and got it off that way. Just take your time.

When reflowing, I would recommend using flux, putting some new solder on the tip every few pins, and carefully going from the pads to the pins. Take your time. It might take a few reflows to get it working.

Thanks,

I got it pried apart. I've done one reflow. Used flux but did not add any new solder yet. So far that seems to have fixed the backlight issue. I could tell from when I initially pried it open that some of the backlight connections weren't even physically connected. I had backlight issue pictured before (dark spot) but now the backlight is uniform. No video yet however so I'll reflow those pins again and check again. Just going slow and careful.