General Electric DS3800HMPK1J1J Mark IV Microprocessor Board

The DS3800HMPK1J1J is a General Electric (GE) microprocessor board for the Mark IV DS3800 control system. It contains a microprocessor and EPROM devices for processing and firmware storage, along with a 34-pin connector, two 50-pin connectors, and front-visible status LEDs. Its diagnostic indicators and memory I/O test procedures support board initialization checks and fault identification during maintenance.

Hardware Configuration and Interfaces

The board uses a modular connector at one end and retention levers at the other to secure it in the drive system. Its front-visible indicators include three red LEDs and one amber LED. The board also has a 34-pin connector and two 50-pin connectors for system interfaces; the specific signal assignments are not identified in the supplied data.

Initialization and Status Indication

During power-up, the yellow I'M OK LED should illuminate briefly, turn off briefly, and then remain on. This sequence indicates that the board has completed its initialization tests. If the expected sequence does not occur, the supplied troubleshooting procedure identifies Berg jumper placement and the seating of PROM devices on the attached DMPK or DMPL daughterboard as initial inspection points.

Memory I/O Diagnostics

During initialization, the Mark IV system should display the Memory I/O screen on the CRT for five seconds. If the screen does not appear, the supplied procedure describes routing the printer connection to the HMPK board's JA connector and printing RAM_PROM_TEST_FAILURE_DATA after reinitializing the C processor (CC). The resulting diagnostic output identifies failed cards for further investigation.

Technical Specifications

Frequently Asked Questions

Q: What does the I'M OK LED sequence indicate?

A: The yellow I'M OK LED should turn on briefly, turn off briefly, and then remain on after the board is energized. An incorrect sequence warrants checking the Berg jumper positions and the seating of the PROM devices on the attached DMPK or DMPL daughterboard.

Q: What should be checked if the Memory I/O display does not appear?

A: Check the initialization status and follow the documented diagnostic procedure for the printer connection and RAM_PROM_TEST_FAILURE_DATA output. The required supporting cards differ depending on whether the HMPK uses a DMPK or DMPL daughterboard, so confirm the installed configuration before troubleshooting.

Q: What should be verified before replacing the board?

A: Confirm the complete part number, DS3800HMPK1J1J, and inspect the board's daughterboard configuration and jumper positions. The supplied information does not establish interchangeability with other DS3800HMPK variants; do not assume that a similar model is a direct replacement.