After Marshall discontinued the 6100/6101 amplifiers it was just matter of time before the
supply of now obsolete but programmed 27c64 UVEEPROMS dried up. The most common cause of failure is usually a powertube
arc/short which puts excessive voltage into the heater winding which the MIDI board leaches it's power from. Every part
used is what you would call garden variety, even the 27c64. The reason the 27c64 is so critical is not because of the part
but the program the part contains . Without this program it WILL NOT WORK!
Every chip i sell i program myself using new, not refurb UVEPROMS so i know they are done right and
I back up everyting i do here. I you get MIDI parts from me and are still having issues get in touch with
me. To date i have helped more than 300 people worldwide fix their amps. I never liked the idea of this amp becoming a door
stop, and it doesn't have to.