Is my MIDIFighter Pro bricked?
After years of searching, I was able to get my hands on a MIDIFighter Pro (Beat Masher configuration, board #2804 if anyone is counting). I anxiously plugged it in, and no “LED snake” light show - the only illumination is the LED of the lower-left arcade button. The MIDIFighter Utility doesn’t see it at all. I tried holding down the 4 corners while re-plugging to get into bootloader mode - nothing. I tried holding down the rest button while re-plugging - that makes 15/16 button LEDs light up (the one in the lower right stays off) and as soon as I release the reset button, I’m back to just the lower left button’s LED. I’ve gone through the other button combo bootloader procedures, and there’s no joy. I know the chances are slim since the world is a solid decade past this unit, but any advice from anyone is greatly appreciated. If you’re a tech that understands the working of the Pro, I’m happy to pay shipping and bench fees if you think you can make it work. Thanks folks.
Dude no worries it’s very likely fixable, how much technical knowledge do you have yourself, and are you on Windows or macOS?
As far as technical knowledge, I know how to read the polarity of a LED, I can solder OK, I have spent time computing from the command line, and I’m good at following directions 
I’m on a Mac but with an older version of the OS (10.12) - but I do have another computer with a slightly newer OS (10.13). Thank you for the help!
Ah dude this is deff gonna be doable, I have flashed a MF with custom code before and I know their source code is on GH. Can you check if the mac sees it as a USB device? And if so what kind
Sadly, it looks like the Mac doesn’t see it. I can plug in a working MIDIFighter Classic and that shows up on the USB tree, but when the one-light Pro is connected, it’s like nothing is there. I’m guessing it’s because the Pro isn’t completing its startup. 
If you plug the MF into a charger does it behave exactly the same?
I had not thought to try that! The result was the same - no “light snake” - just that one LED lit.
Here’s one other thought – I have a fully functional MIDI Fighter Classic board (standard MFv1). Can I flash the ROM on that so it sees itself as a Pro, and then swap the board into the Pro case and have that work? I already know I’d need to do a little drilling around at least one of the corner mount holes (It’s so funny how many crazy little thing you learn about how these things were built when you tear them apart a bunch of times), but other than that it seems like it should work - I have headers soldered to the expansion ports on the MFv1, so the ribbon connector isn’t an issue.
That would definitely work I’d say but It kinda sounds like it could just be a faulty connection of the USB’s D- and D+ signals, maybe you could try to debug it with a multimeter?
Excellent thought, and I know how to test continuity with my meter! After looking at the schematic, I see that D- makes its way to pin 30, and D+ makes its way to pin 29 on the AT90USB162 chip. However, when I look at the board IRL, I’m a little disoriented, and I’m not sure which is the right pin. Could you give me some direction? I tried to attach a pic of the board, but it doesn’t seem to have made it. 
OK, I’ve been able to verify with my meter, some magnifying glasses, and steadier hands than I figured I could manage, that I’ve got proper 22R resistance between D- and pin 30 on the AT90USB162 chip and D+ and pin 29. I think that’s a good sign… I hope that’s a good sign…
In other news, I tried seeing if MIDI Monitor could “see” the board, and it does not. It’s like it’s getting stuck in its startup process and just hanging.
And after spending a little more time and reading a lot more datasheets, i seem to have good connectivity around all the chips. I think this is a good sign.
And nothing under system information’s USB device tree right? I’ve got this:
(it got compressed to shit but you get the idea)
Correct - I know exactly what your pic is describing, and yeah, I get nothing showing up there at all.
Are there any programming headers on the MF board (not the daughterboard) you might want to try reflashing the board. Even just to check if that’s possible.
Have you tried doing that by using the bootloader switch on the board?
As a last-ditch effort you could try removing the ESD Protection chip, but I’d try everything else before doing this as it likely won’t help.
My board has the two red buttons soldered on for the Reset and Boot spots, but I can’t seem to get the board into bootloader mode, eithber by the old school 4-button method, or using the red buttons. One interesting thing that happens, though, if I hold down the Reset red button and plug in the USB, I get one of 4 different combinations of the button LEDs lit up:
.*
**..
***.
or
..
**..
*…
or
.*
*.
***.
or
***.
but then, no matter which one I had, when I hit the boot button I get
…
…
…
*…
just like when I plug in the USB with no buttons pressed.
I don’t know if this is going to help me or shed any new light, but I found the “Bricked MIDI Fighter Reset Guide” here: https://s3.amazonaws.com/CGSupport/Bricked+Midi+Fighter+Reset+Guide.pdf
Even if it doesn’t wind up helping me, having this link in a thread might help someone else in the future… more info on my situation soon…
