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→Repairs -
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== Repairs - ==
After confirming the firmware of the CPLD and the Flash seem intact. I flashed the firmware onto a new NOR flash chip. I also replaced the SRAM (these are almost a consumable, and I have had one of this range fail before, in a different package)
I replaced the other chips I had removed. I fixed the traces on the board with new pcb traces. I had to repair a leg of a custom Alesis IC (there are three, two small one large). The chip was bridged with a factory bodge of a capacitor. Removing that, broke the leg off the IC. I was able to grind away the epoxy and solder a new leg in place. Almost 20 traces have been repaired.
The LEDs had metal fatigued off with all the repairs. I ground away the solder resist and was able to solder them directly to the board again. (they are a custom design package. Also, I like to use the original. Only the legs were broken after all)<gallery>File:Dif-at-tracerepair.png|alt=Traces replaced and connected.|Traces replaced and connected.File:Dif-at-tracerepair2.png|traces tinned (way too much, I took some off with wick)File:Dif-at-tracerepair3.png|placing componentFile:Dif-at-tracerepair4.png|CPU traces repaired. Sorry, not a great shot</gallery>
After some months working on this, and seeing the LEDs blink again (it took an embarrassingly long time to realise they were pulled high) I was satisfied I could take a short break from it. I will complete the repair by fully testing it and running the UART Monitor program.
I will update this when the device is fully tested. For now, be assured that it's back together, repaired, and starting to boot. There could be some small issues, which can be discovered and fixed with the UART function. I could only continue the marathon with a reboot myself.
Thanks for reading. I hope it's interesting and or useful!
==NOTES -==
Ic 18 (opto-isolator) -
Ic 16 (opto-isolator) - to Ic 28 (multiple pins, bridged) (mux)'<nowiki/>'''<nowiki>'''''</nowiki>'''''<nowiki>'''''</nowiki>'''''
Ic 14 (opto-isolator) - to Alesis cpld pin 58
