Hello, everyone.
My KJ3 ProTracker, PCB version 07-7782 rev.C was behaving excellent, until... The back fan broke, I haven't noticed it and now it flashes both red leds, no display, no LCD, and gives me the audible "message" of overcurrent (i think).
Once I put 220V AC :-\ on the A channel, of course it broke and burned some components inside (at least two relays and resistors R87, R88 and R133, already replaced by me), but it didn't resolve the problem, so I was forced to use the B channel;
Some time later the LCD started to change contrast at power-up, but I could revert it to good thru menu settings;
Now, after the fan broke, it probably got thermal shock and broke some other components...
Heres´s something I found, searching for the problem (I'm using the schematics for a ProTracker I 06-3090 rev. C version):
I have a thermal camera, and all AMPOP chips connected to +12V and -12V or +24V and -24V heat up a bit, but the voltages are OK;
Found the U413 SRAM (IDT7164) heating up, normally SRAMs don't heat up that much;
The two Spartans don't heat up at all, but they have their voltages OK;
All voltages are nominal from the regulators and modules (+5V, +12V, -12V, +15V, -15V, +24V and -24V);
Reflashed the flash (no pun intended) again with the KJ3 firmware backup I have, to no avail.
So, my hands are tied up, now. I do have a simple XY "octopus circuit" I've created to try to fix the problem, but I'm not willing to ruin more my dear protracker...
Is there anyone who could help me?
Thanks in advance.
-= Paula Silva =-
you might be better off purchasing 1 or 2 of those non functioning Protracks on eBay. all of them have the main board included.