Sega Naomi I/O Board Repair?

[LuKa]

Hey there I have about 4 Sega Naomi i/o boards that have various faults, 3 of them come up with i/o board not found (tested on multiple machines) and one is detected by the Sega Naomi but it thinks a few buttons are being constantly pressed. Are these things repairable? Is it a matter of reflashing the big Toshiba chip on the board for the ones not detected or replace the USB port of something? With the one with the stuck buttons I noticed some black components missing from the board, check this image out:

http://i.imgur.com/lcxLzp6.jpg

And here is another one for reference:

http://i.imgur.com/b7WaFx2.jpg

I noticed that D5,6,7,8,9 are missing, they look like SMD titanium capacitors, does anyone know what they are exactly and if so where to get them? I'm guessing that this might have something to do with the stuck buttons correct me if I'm wrong.

Most people may say just buy another one but it feels such a waste to throw away 4 of them.

Any help or advice would be much appreciated

 

[RealMFnG]

What I/O boards are you using when you ran into the I/O board not found error? The Capcom I/O or the Sega I/O? I have ran into the I/O board not found error and resolved it by tuning the power to no higher than 5.1 12 volts exactly when using the Capcom I/O. Give it a shot and see what happens.

The NAOMI is notoriously fickle with its power requirements. As for fixing them, the widely recognized expert, Ken at irepairsega.com, charges about $95 for the job. New NAOMI's are about $55 shipped. Sad, but that is how they end up in the dumps.

 

[Derick2k]

D5-D9 are Diodes, not capacitors. Send them out to someone that can properly identify the missing components and replace them and/or properly repairs these, and the USB plug is not USB, so dont go plugging it to a PC usb port.

If you cant repair these or dont want to spend the $$ to, donate them to someone that might.

 

[twistedsymphony]

Ken at irepairsega.com is the only one off hand that I can think of that fixes stuff like this. however the price to fix these boards is likely more than just buying another working used one. I agree with Derik, if you're not going to spend the money or fix them yourself then sell them cheap as broken or give them to someone who wants them for parts or to try to fix them... it IS a waste throwing them out, which is why you should never do that.

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the one with the missing diodes (and they ARE diodes) is likely showing stuck buttons because those are missing. it looks like something physically damaged the PCB and pulled those components off, it looks like it ripped the traces right off the PCB with them so you'll likely have to do some trace repair to fix that one.

As for the one that's not recognized the first thing I would verify is that the relay is clicking on when it's powered up and that the power LED comes on. Of course you want to inspect it for physical damage as well. If you think the ROM is corrupt you can always pull the IC read the data off of it and verify it against a known good image. (or even easier, just swap the ROM with your other I/O board) once you've verified that I would recommend poking around the ICs with a logic probe and comparing the results to a known working unit until you've isolated the problem areas.