RaspberryJAMMA fried? No power to rPi3

[shaikoten]

I've been a happy user of the RaspberryJAMMA for nearly a year! I upgraded from an ugly old frankenstein Dyanmo showcase cab to a much sleeker New Astro City about two weeks ago, and swapped the RaspberryJAMMA over to my new machine with little issue: It was getting a low voltage warning, but I gave the slightest of upwards tweaks on the PSU adjustment and it worked fine ever since then. Until yesterday.

A new control panel came in the mail, and I was converting from 4 button (used to be Neo Geo layout) to 6 button. I put the new CP in, tested it, the three stock JAMMA buttons worked fine. Then I went to re-wire the kick harness for the new CP, which I was not using previously on this machine, and that's when things went wrong.

I was working without sufficient light and got a couple of the wires swapped up with the leads for grounds instead of those for the P1 and P2 4-6 because I couldn't make out the color. So when I plugged it in and started it, the Raspberry Pi still booted fine, but when I got into game the 4-6 buttons were all screwed up as one would imagine. So I kept making adjustments to the kick harness wiring. During the process the Raspberry JAMMA was not secured and was usually just laid on an anti-static mat, and it probably did jostle around a fair bit.

In the middle of testing the kick harness, the screen blacked out, the pi appeared to crash, and when I tried to reboot, nothing happened. Since then, I have tried powering the raspberry pi through USB, which works fine. I have tried with and without the kick harness, and with the switches by the kick harness input in all positions. I've disassembled and re-assembled the pi and raspJAMMA combo to ensure all connections were stable. I've attempted to plug it into my old machine, which does NOT work. I've also looked for signs of visual defect on the RaspberryJAMMA. The fuse appears to be intact, and I don't see anything resembling a blown capacitor. The New Astro City and the Dynamo cab both work with their other PCBs, a Neo Geo and CPS2 respectively.

Anyone have any clue what this might be? From my troubleshooting it seems like it must be an issue with the RaspberryJAMMA, not the pi or machines themselves, though without any visual signs of damage I'm not sure what it could be. Thanks for reading my saga here, just wanted to be thorough with all the steps I've taken!

[dee2eR]

Do you have a multimeter? (if not get yourself one, they're pretty much needed in this hobby). It's good to be able to accurately measure voltage as well as continuity test, can save a lot of headaches.

With the Pi working when powered through USB I'm confident your issue is the fuse. Test the continuity accross the fuse, it will look no different when blown but is almost certainly the reason your Pi cannot get power from the JAMMA edge.

[shaikoten]

Yep, you're right! No continuity on the fuse. Not sure why I didn't think to check that before. Any recommendation on what sort of fuse I should replace it with? I'm fine soldering a new one in.

[dee2eR]

any 1A fuse should be ok and is safe for any Raspberry Pi, the original fuse is a 1A 'very fast acting' axial leaded type.

If you plan on running lots of USB devices and a Pi3 you can upgrade the fuse to 2.5A safely but in normal use 1A is adequate, ordinarily 5v use is under 0.7A even for a Pi3 (based on numbers provided by my work bench power supply).

[shaikoten]

Thanks so much! I do plan on loading up on the USB devices when I expand my build, and I'm already overclocking, so that 2.5A number is great to know.