DECmpp 12000/Sx Model 100

This hardware service manual details the operation, maintenance, and repair of the DECmpp 12000/Sx Series and 12000–LC/Sx Series systems. It includes comprehensive information on system power-up and power-down sequences, control panel indicators, and power supply voltage adjustment. Detailed procedures are provided for removing and replacing Data Parallel Unit (DPU) components such as card cage PCBs, power trays, fan trays, and lightpipe PCBs. Additionally, the manual covers diagnostic software usage, fault interpretation using log files, and guidelines for backplane jumper configuration during PE array upgrades.