When the main RIFA delayed smoke generator popped on the Kaypro 4 power supply (Boschert XL53-3601R) it took out the switching transistor, Q1, so I need to replace it.
However, the only part of the transistor can with any corrosion is the part with the type number. All I can read are the final...
I've a Sun 3/80 which whilst in storage developed a fault in the decode1 chip meaning that it can't output the /RD signal to the serial SCC. Given that this is required at an early stage in the boot the machine just flashes the LED briefly and sits there polling writing to the status register...