dillingerradio
Professional
Hello all.
I recently picked up a KONAMI X-Men.
The previous owner did a bang up job repairing the sound module; however, in an endeavor to gain more experience, I opted to install a pxlmod reproduction unit.
Removal of the previous audio module failed catastrophically, to my horror, and the extraordinarily brittle unit cracked under light prying pressure during desoldering. I was lucky that the 054321 ASIC was undamaged in the process, and I was able to salvage it for use, saving me from having to source one. I managed to recover the chip from the piece of PCB it was clinging to with the use of a heat gun and my soldering iron after using the iron to clear the coating on the legs and the heat gun to fail the adhesive. After significant effort (I have zero prior SMD soldering experience, so this was challenging), I managed to stick it down to the pxlmod board. I tested that it was properly installed by verifying continuity between each leg and its pad (to make sure the leg wasn't actually lifted) and then checked each individually for shorts with its neighbor. It tested good for continuity and no shorts were found, so I installed the unit in the socket I had soldered in the original's place.
Initially, the machine booted to the ROM check where it failed 6F, 7C, 4E, and 2D. To my understanding, this failure state indicates a bad audio module. Suspecting that the issue may have been the result of a short I checked the solder side of the board, and thereupon found the culprit: a tiny thread of solder that had shorted two pins. I corrected the issue and inspected the rest of the sockets both visually and with my multimeter to verify no other shorts (something I should've thought to do prior to install.) Because I had removed the module prior to completing the correction, I double checked that the ASIC hadn't sprung a leg. My checks for continuity were all good (no shorts, no lifted legs,) and I reinstalled the module. I attempted to boot the unit again. To my great relief (and then, dismay,) the unit boots to the ROM check where it indicates all good, then reboots- staying in this cycle indefinitely until powered off.
Any ideas on what I should be checking that would cause a boot loop?
Here's a gif of the loop in action. It starts right as the text goes out, and ends right as the text is about to go out, so that it loops in a manner consistent with how it presented in situ:
Everything worked prior to my effort, so I know the board is good. Just trying to figure out what I did that would cause this looping.
Cheers.
(On a side note: if the previous owner happens to be on this forum and sees this, I am genuinely sorry. It was a great repair and I intended to retain it as a backup. I'm still surprised it cracked. It really was only very light pressure to check if the desoldering had loosened anything up.
)
I recently picked up a KONAMI X-Men.
The previous owner did a bang up job repairing the sound module; however, in an endeavor to gain more experience, I opted to install a pxlmod reproduction unit.
Removal of the previous audio module failed catastrophically, to my horror, and the extraordinarily brittle unit cracked under light prying pressure during desoldering. I was lucky that the 054321 ASIC was undamaged in the process, and I was able to salvage it for use, saving me from having to source one. I managed to recover the chip from the piece of PCB it was clinging to with the use of a heat gun and my soldering iron after using the iron to clear the coating on the legs and the heat gun to fail the adhesive. After significant effort (I have zero prior SMD soldering experience, so this was challenging), I managed to stick it down to the pxlmod board. I tested that it was properly installed by verifying continuity between each leg and its pad (to make sure the leg wasn't actually lifted) and then checked each individually for shorts with its neighbor. It tested good for continuity and no shorts were found, so I installed the unit in the socket I had soldered in the original's place.
Initially, the machine booted to the ROM check where it failed 6F, 7C, 4E, and 2D. To my understanding, this failure state indicates a bad audio module. Suspecting that the issue may have been the result of a short I checked the solder side of the board, and thereupon found the culprit: a tiny thread of solder that had shorted two pins. I corrected the issue and inspected the rest of the sockets both visually and with my multimeter to verify no other shorts (something I should've thought to do prior to install.) Because I had removed the module prior to completing the correction, I double checked that the ASIC hadn't sprung a leg. My checks for continuity were all good (no shorts, no lifted legs,) and I reinstalled the module. I attempted to boot the unit again. To my great relief (and then, dismay,) the unit boots to the ROM check where it indicates all good, then reboots- staying in this cycle indefinitely until powered off.
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Any ideas on what I should be checking that would cause a boot loop?
Here's a gif of the loop in action. It starts right as the text goes out, and ends right as the text is about to go out, so that it loops in a manner consistent with how it presented in situ:
Everything worked prior to my effort, so I know the board is good. Just trying to figure out what I did that would cause this looping.
Cheers.
(On a side note: if the previous owner happens to be on this forum and sees this, I am genuinely sorry. It was a great repair and I intended to retain it as a backup. I'm still surprised it cracked. It really was only very light pressure to check if the desoldering had loosened anything up.
)
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