REU for Pi Zero 2 Boot Problem

[suk2013]

Hi all,
I assembled myself REU pcb for pi zero 2 w. When I started the C64 with the REU plugged in the cartridge expansion slot, I got garbage graphics shown. I had to press restart for the REU to show the menu. I also had to press reset after pressing X for the C64 to show my RAM size selection.
I wonder if I installed the wrong components.
I also did by mistake plugged in on the wrong pcb side once (I didn't notice the "this side up" on the pcb because my pcb covered by the case I installed) and twice had the jumper put on and powered the pi zero 2 w externally. I wonder if the components are still good.
Any help would be appreciated.
Here are my pcb pictures.

[futureretrofusion]

Is this on each boot... But does it work properly once you get the menu to load? Any glitches when you play nuvies or koala videos ? The components look good to me, besides it's working. No chance that your cart port needs a clean?

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On Sat, 7 Jun 2025, 16:37 Han, ***@***.***> wrote: Hi all, I assembled myself REU pcb for pi zero 2 w. When I started the C64 with the REU plugged in the cartridge expansion slot, I got garbage graphics shown. I had to press restart for the REU to show the menu. I also had to press reset after pressing X for the C64 to show my RAM size selection. I wonder if I installed the wrong components. Here are my pcb pictures. Any help would be appreciated. 20250606_232035.jpg (view on web) <https://github.com/user-attachments/assets/fb8d3f96-a11a-48a2-926b-e61aee212ac1> 20250606_232042.jpg (view on web) <https://github.com/user-attachments/assets/42ee4ae3-186a-47e9-81ca-7fc0d36be8f5> 20250606_231846.jpg (view on web) <https://github.com/user-attachments/assets/e9c8ba5a-78f4-4054-bc35-4855c2939654> 20250606_231905.jpg (view on web) <https://github.com/user-attachments/assets/75780dc8-1990-4ce1-97b8-1b70d1954d87> 20250606_232022.jpg (view on web) <https://github.com/user-attachments/assets/0fe5e67f-718e-417b-ac57-fc772be9a638> — Reply to this email directly, view it on GitHub <#63>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A3ZE5REY5HVPA3WMLX3QUXL3CKCC5AVCNFSM6AAAAAB6ZRYWF6VHI2DSMVQWIX3LMV43ERDJONRXK43TNFXW4OZYGQZDMOJZGM> . You are receiving this because you are subscribed to this thread.Message ID: ***@***.***>

[Markeno76]

As it says, don't ever power it both internally and with the USB port at the same time. Could you have broken something, Sure, did you? , no idea.. and I won't try it myself.. Guessing that it is mostly working minus a little issue, maybe you didn't harm anything significantly. I would expect backfeeding power from one power supply to the other, it isn't a good thing and I don't know what you are most likely to damage doing that.

Also if you are powering it from the C64, and it has that behavior, I would expect it is because the power is a bit low, and because the C64 starts quicker than the PI fully initializes. To me it isn't worth trying to power it with the C64 considering it can be potentially troublesome, also if you find it always works on the First Power up by using USB power ("instead"), then I'd just stick to USB Power only.

[suk2013]

I tried to load nuvie movies. I can hear sound/music but video was bad. I also had to use external power adapter on the pi zero to be able to play nuvie videos.
I did clean the port slot with connector cleaner and deoxit.

[Markeno76]

That looks like you are running a Nuvie on a NTSC computer. They only work on PAL machines. Although I did find 1 that worked on NTSC.

[frntc]

Hard to tell if all ICs are still working fine after flipping the RAD :-/

Does the menu (when if launches) run stable? Did you try a REU-test-program? (https://www.retro-programming.de/programming/nachschlagewerk/nice-to-know/reu-programmierung/#)

[futureretrofusion]

Have you tried cleaning the cart port? Not getting enough power to the RAD via the cart port isn't common. Could be some resistance in the contacts? (I've seen something similar like this before when my cart port has been dirty) Use an old cart with some cleaning alcohol on both sides If no improvement you go over all the joints with a soldering iron and flux ensure no marginal connections in the components

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On Sun, 8 Jun 2025, 17:22 frntc, ***@***.***> wrote: Hard to tell if all ICs are still working fine after flipping the RAD :-/ Does the menu (when if launches) run stable? Did you try a REU-test-program? ( https://www.retro-programming.de/programming/nachschlagewerk/nice-to-know/reu-programmierung/# ) — Reply to this email directly, view it on GitHub <#63 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/A3ZE5RF2JVJVMPWYBYXAZP33CPQCTAVCNFSM6AAAAAB6ZRYWF6VHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTGNBQGA4DEMA> . You are receiving this because you commented.Message ID: ***@***.***>