Hi there
i own a KS32 for a while after a bad connection to the Display Board my buttons stops working, but the display was ok and there was a booting of the Systems ROM so i could play it and work with it over midi commands.
Few weeks ago i saw a psoting about a user wich could solve the same problem over reflashing the eprom with a faulty Checksum.
So checked my roms to and the checksum was wrong reflashed the uppper and lower roms with matching checksum.
The KS32 now stucks in Service Mode with no reaction at all only the Button #HEX numbers are displayed pushing any button.
So i did a lot ot testting last weeks all the Testpoints are ok °Voltage are in specs.
LM2926 got 8,9 Volt on pin 1 Input and 5 Volt on PIN 2 / 3,9 Volt on PIN 5
Tested the voltage on all the IC and CPU all inside 4.8 to 5 Volt.
Tested the Clocks with Analyzer @clocks working fine.
Tested the Rst / Halt / Brr pins shows activity Low to High
checked the Voltage on the transorfmer Board all inside specs only
J12 PIN 1 and PIN3 are higher (7V on the PCB ) i got 8.9 Volt.
tried all the pins from the Upper and Lower Rom and the connections to the
Ram Chips , GND Voltage all looks fine.
Cleaned up pins and Connectors, checked Resistors and Condensators, checked with light lamp for broken traces.
buyed two new empty Eproms reflashed the upper & lower .bin
nothings works, still in service mode.
So yesterday i started to check out the UART & the 6500/11 on TX and RX pins
no activity goes high but no data flow.
i wonder if this means a broken 6500/11 or UART chip or if the activity does not
start at all without booting up.
MC68000 getting bit hot, al other chips remain cold will order a new MC68000
I really need some professional help or somd tips how to deeper testing the UART CPU and 6500/11 communications.
actually there is no motherboard in stock or in ebay so my only chance is to get it working again even if only over midi.
thx
Maurizio