MiSTer FPGA Forum

I got my MiSTer pre-built from Ultimatemister.com with an aluminum case.

Very often when I touch it, I get a static shock. I didn’t think much of it until now, but today I noticed that when I got one such a shock while it was on, one of the USB ports’ green light turned off for a second. Now that has got me scared because it’s making me think those shocks aren’t harmless to the device.

Anyone else experience something like this? Any advice?

My advice is to ground yourself before touching electronics. ESD can ruin it. With a big metal case the risk is lessened a little, but it's not reduced to zero. Just grab some metal nearby before you touch the MiSTer.

What kind of surface are you standing on when it happens? Plastic floor protector? Using slippers? You need to be better grounded, otherwise you’ll keep zapping your Mister. Wear sweaty socks.

I'm on my living room carpet when I'm touching it. That certainly might be the problem then.

I guess my bigger question is: Why is a shock on the case reaching the innards of the MiSTer? Shouldn't this be shielded in some form? I've gotten many static shocks from touching PC cases before but I've never seen it have an impact on what's inside.

If the metal case uses metal screws to screw into the PCB holes, and those PCB holes are tied into the ground for the power circuit, then it generally should be fine, but the problem is all things in the world don't behave 100% as they theoretically should. Maybe some of your input ports are touching the metal housing, etc... Just find a way to stop shocking yourself

Because its not a diode and the current goes both ways iirc ..

AtomicShroom wrote: ↑Tue Jun 21, 2022 5:46 pm I guess my bigger question is: Why is a shock on the case reaching the innards of the MiSTer? Shouldn't this be shielded in some form? I've gotten many static shocks from touching PC cases before but I've never seen it have an impact on what's inside.

Theory is all well and good, but in case of an expensive and hard to obtain device such as MiSTer you really should be extra careful. It's not a PC, from what I heard these boards are generally a bit more fragile. So if I was you I'd really follow aberu/C-R-T's advice and take these extra precautions.

Which is what I usually do - take my slippers off & touch some metal - before handling MiSTer and my old computers. And even so, I managed to fry something in my beloved Amiga 500 in a freak short circuit accident a few weeks ago (sob).

akeley wrote: ↑Tue Jun 21, 2022 7:49 pm Which is what I usually do - take my slippers off & touch some metal - before handling MiSTer and my old computers. And even so, I managed to fry something in my beloved Amiga 500 in a freak short circuit accident a few weeks ago (sob).

Sorry for your loss. Hopefully it's repairable? I recently lost my arcade cabinet's CRT (Kortek 2914F) shortly after fitting new controls and replacing the old PC with the MiSTer. I believe mine is repairable, though I don't have the skill to do it myself, so I have to find someone to repair the chassis. Pretty heartbreaking when old, beloved electronics die.

Thanks...I'm about to send it off to a local retro-hardware repair shop. It's not totally dead, there is just some gfx glitching, so I remain hopeful. I guess it's easier to fix thsi kind of electronics than find people who deal with CRTs so I wish you luck with your search.

Yeah, it's not fun when it happens, but tbh I've been quite lucky in this regard in the ~3 years since I got the hardware collecting bug. It's the first time something has died on me and I've never bought a dud yet either, so on balance I think it's not too bad