Trimmed Wii random USB crashing

samu

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Hi everyone, love this site and all its helpful people and content, I've had a lot of fun with my project. I want to trim a Wii so that it can fit in a 5" portable color CRT TV, so that I can play console+CRT super smash bros. melee on the go, all in one and in a form factor that can fit in a backpack, with only an external PSU required.

Everything was going perfectly, I did the U10 relocation before trimming, and the trimmed 4-layer Wii was booting into RVLoader, playing games, and running cool and stable as I practiced in Melee's training mode for hours with no crashing.

The problem, however, is if I turn the music on (it loads from the disk) or choose a stage which needs to load extra content from the disk while playing (like temple or pokemon stadium), I consistently crash somewhere randomly between 0-30s of play time. My immediate thought was that this was EMI radiating from the CRT, which has a huge flyback transformer, so I turned the CRT off completely and tried again, but the results were exactly the same. Again, if I chose a stage which did not need to load from the disk while playing, it would run for hours with no crashing. The same was true for other games, I could play Super Mario Sunshine perfectly, until it tries to load a cutscene, causing a crash.

Since the crashing only occurs when in-game and trying to load something from the disk (USB), I can't see it being anything else.

At first I was using 30awg wire of a considerable length twisted very tightly with a drill, so I switched that out for twisted 34awg magnet wire of a length of about an 1", but there was no improvement.

I'm using the current recommended drive, the SanDisk 128GB USB 3.1 UltraFit formatted to FAT32 with 32K clusters using guiformat. I've also tried with a Kingston 128GB drive and a USB2.0 to microSD adapter, all individually formatted and with their .iso files downloaded independently and from different sources in case there was a corruption problem.

I've soldered to both CM1 and CM2 and it's the same with both. I've never bypassed these CMCs. I've even tried using a tiny ferrite bead and running the 34awg through that. I've grounded the USB port. I haven't tried a clean reinstall of RVLoader, as I don't think the problem lies with RVLoader if the crashing almost always occurs in-game (sometimes I'll get a DSI exception navigating through RVLoader). I'm also hesitant to do this reinstall in case the bad USB writes some corrupt data to the NAND or whatever and bricks the whole Wii.

One time I turned off every electrical appliance in the house (lol) and disconnected the 5V fan (in case it was emitting EMI) and amazingly it didn't crash for 2 whole minutes until I turned it off as I was afraid of it overheating. However, I was unable to ever recreate this even immediately after, with everything still turned off. So, it seems to happen regardless of the 'level' of EMI. Still, I don't know what else it could be.

I've checked the 5V line with an oscilloscope and it's a stable 4.9V with 0.01Vpp ripple (or was it 0.1Vpp?), well within the specified USB 2.0 requirements. I've also monitored the 5V line as the crash occurs, and haven't seen anything abnormal like a voltage drop. It's coming from a PTH08000W, which is exactly like the 08080W except it has an auto-track feature that I disabled by shorting two pins.

I've resoldered every connection on the board at least twice.

Somewhat counter-intuitively, I have never seen it crash while trying to load a game, which you would think is when most of the USB data transferring occurs.

I guess the biggest question is whether or not this crashing has always been a problem even before the trim. I'm 99% sure this isn't the case, because I played it for a couple of days from the USB before trimming, and surely I had the music on at some point and would have induced a crash or I would have gotten a DSI exception in the menu. Still, there is that 1%.


Has anyone experienced something like this? Any ideas would be greatly appreciated. I've had this problem for months now and I'm pretty close to just using it as is and only playing melee on tournament stages, but I would really like to play other GC/Wii games on it.

I'll attach some pictures below. Don't mind the mess of wires, i've flipped it over and tangled the wires a hundred times while trying to figure this out. Also, ik it's not good to have exposed wires, but I promise they haven't shorted. It was just temporarily like that while I tried CM2.


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Stitches

2 and a Half Dollarydoos
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That is indeed a very specific issue. I can't say I remember anyone reporting this same problem before, but we can have a go at resolving it. First thing I want to ask is whether you have 2 ground wires going from the regulators to the Wii? Insufficient ground is a common cause of seemingly unrelated issues, so adding a second ground wire would be a good step 1
 

samu

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Jun 1, 2023
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That is indeed a very specific issue. I can't say I remember anyone reporting this same problem before, but we can have a go at resolving it. First thing I want to ask is whether you have 2 ground wires going from the regulators to the Wii? Insufficient ground is a common cause of seemingly unrelated issues, so adding a second ground wire would be a good step 1
Holy sht I connected a 2nd ground wire between the regs and the board and the crashing is completely gone. 99 stocks 4 CPUs on temple, playing through mario sunshine, no crashing, no DSI exceptions.

Thank u so much for the reply, I can finally put this thing together! I guess it didn't cross my mind since I already had two ground wires connected to the wii, but one was just going to the gcc board and not to the regs. I wonder why the problem manifested in such a weird way. Thanks again ur the goat :))
 
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