Jump to content

VAXstation 3100 Maintenance Guide

From RetroTechCollection
Model 30 with the cover off, showing the battery pack and its cable to the system module (DEC, EK-285AA-MG-001, Figure 4-21)

Routine care of the VAXstation 3100 covers its siting, the rechargeable battery that keeps the console settings, the power supply, and the field-replaceable units inside the system box. DEC's VAXstation 3100 Maintenance Guide (EK-285AA-MG-001) describes the Models 30 and 40; the Models 38, 48 and 76 use the same enclosures and power supplies.[1][2]

The system box contains a mains switching power supply with capacitors charged to mains voltage. Unplug it before removing the cover. The monitors are separate CRT units covered by their own DEC service guides; see CRT Discharge Procedure before opening one.[3][2]

Siting

[edit | edit source]

DEC's checklist for the Model 40:[4]

  • Keep air moving around the unit so heat and dust do not build up, and keep the vents on each side of the system unit clear.
  • Do not stand the system unit on its side, since that blocks the vents and can overheat it, and do not put it directly on the floor.
  • Keep it away from heaters, photocopiers, direct sunlight and abrasive dust, and keep food and drink away from it.
  • With a TZ30 tape drive fitted, keep the room between 15.5 and 32 °C and the relative humidity between 40% and 80%.
  • After moving the equipment in from the cold, let it reach room temperature before switching on.

The system unit adjusts itself to 100–120 V or 220–240 V mains.[5][6]

Opening the system box

[edit | edit source]
  1. Switch the system off.
  2. Remove the two cover screws at the back.
  3. Slide the cover forward and up off the system box.

[7] Wear a static wrist strap and use a static mat when handling the FRUs. Do not unplug the keyboard, mouse or tablet with the power on. DEC treats the LK201 keyboard as a single FRU and says not to remove its keycaps or take it apart.[3][8]

NVR battery

[edit | edit source]

The nonvolatile RAM holds the default boot device and flags, the keyboard language, the time and date, and the battery's own charge status. It is backed by a rechargeable 5 V battery pack, DEC part 12-19245-00, held in a holder in the system box and cabled to the system module.[9][10][11]

A low battery shows in the power-up summary as "? D 0050 0000.0005". The pack charges whenever the system is on; DEC's figures for a full charge vary within the same manual, from about 17 hours of running to 24 hours and to at least 25 hours of continuous power for a new pack.[12][9][11] If the low-battery code has not cleared after an hour of continuous running, DEC says to check the battery cable, then replace the battery and let it charge.[9]

To replace the pack: remove the cover and the drive mounting panel, disconnect the battery cable from the system module, and lift the pack out of its holder.[11] If the old pack shows any leakage, check the board and the holder around it; see Battery Explosion, Capacitor or Corrosion Damage.

Power supply

[edit | edit source]

The Model 30 (and 38 and 76) use the H7821 supply; the Model 40 (and 48) use the H7822. Restorers report leaking electrolytic capacitors in both. Checks, output voltages, removal and the capacitor lists are on VAXstation 3100 Power Supply Guide.[10][2]

System module and memory

[edit | edit source]

The system module (KA42-A on the Models 30 and 40, part 54-17312-01) carries the CPU, the NVR circuits and the Ethernet ID ROM. If the module is replaced, move the Ethernet ID ROM from the old module to the new one, with its notched pin 1 the same way round, taking care not to bend its pins. When refitting the module, feed the connector end through the openings in the rear of the box first, push it back to engage the connector ground tabs, then snap it onto the locating standoffs.[11][10] Memory modules are MS42 types of 4, 12 or 16 MB.[10]

VAXstation 3100 Model 30 and 40 FRUs (DEC Table 4-1 and Appendix H)
FRU DEC part Removal (Model 30)
System module KA42-A 54-17312-01 Section 4.2.9
Memory module MS42-AA, -AB, -BA, -CA Section 4.2.8
SCSI/SCSI or ST506/SCSI MSC module 54-17445-04 or 54-17314-02 Section 4.2.3
8-plane graphics coprocessor 54-17282-01 Section 4.2.7
Battery pack 12-19245-00 Section 4.2.10
Power supply H7821 (Model 30), H7822 (Model 40) Section 4.2.11
RZ22 or RZ23 disk, TZ30 tape, RX23 diskette RZ22-E, RZ23-E, TZ30-AX, RX23-AA Sections 4.2.4 to 4.2.6

[3][10]

For the drives, see Hard Drive Maintenance and Repair and Floppy Drive Repair.

SCSI and Ethernet terminators

[edit | edit source]

The power-up tests report an error if the ThinWire Ethernet port is not terminated or the standard Ethernet connector is left open, so keep the terminators or loopback connectors in place.[12] The external SCSI port uses a 68-pin connector with a DEC pinout; it is SCSI-1 single-ended, not wide SCSI. Malte Dehling publishes a replacement terminator design using a TE 786555-7 connector and two Bourns 4611X-104-221/331 resistor networks, as an alternative to DEC's terminator 12-29635-01.[13]

[edit | edit source]

References

[edit | edit source]
  1. ↑ DEC, EK-285AA-MG-001, p. 88, section 4.1.
  2. ↑ 2.0 2.1 2.2 Malte Dehling, "DIGITAL VAXstation 3100 PSU Repair", GitHub repository README, github.com/mdehling/vs3100-psu-repair. Supplies by model; capacitor problems. Community source.
  3. ↑ 3.0 3.1 3.2 DEC, EK-285AA-MG-001, pp. 90 to 91, section 4.2, Tables 4-1 and 4-2. FRU list, static precautions, monitor guides.
  4. ↑ Digital Equipment Corporation, VAXstation 3100 Model 40 Owner's Manual, EK-266AA-OM-001, January 1989, p. 2-1, "Choosing the Right Location" (File:VAXstation 3100 Model 40 Owner's Manual (EK-266AA-OM-001).pdf).
  5. ↑ DEC, EK-266AA-OM-001, p. D-1, Table D-1. Input voltage.
  6. ↑ Digital Equipment Corporation, VAXstation 3100 Cover Letter, EK-393AA-CL-001, December 1989, p. 3 (File:VAXstation 3100 Cover Letter (EK-393AA-CL-001).pdf). Automatic voltage adjustment.
  7. ↑ DEC, EK-285AA-MG-001, pp. 91 to 92, section 4.2.1. Cover removal.
  8. ↑ DEC, EK-285AA-MG-001, p. 106, section 4.2.12. Keyboard.
  9. ↑ 9.0 9.1 9.2 DEC, EK-285AA-MG-001, p. 24, sections 2.5 and 2.5.1. NVR contents; low-battery procedure, 24-hour charge.
  10. ↑ 10.0 10.1 10.2 10.3 10.4 DEC, EK-285AA-MG-001, pp. 246 to 247, Appendix H, recommended spares list.
  11. ↑ 11.0 11.1 11.2 11.3 DEC, EK-285AA-MG-001, pp. 103 to 105, sections 4.2.9 and 4.2.10 and Figure 4-21. System module, Ethernet ID ROM, battery pack; at least 25 hours to charge a new pack.
  12. ↑ 12.0 12.1 Digital Equipment Corporation, VAXstation 3100 Maintenance Guide, EK-285AA-MG-001, February 1989, pp. 9 to 10 (File:VAXstation 3100 Maintenance Guide (EK-285AA-MG-001).pdf). Low battery and Ethernet termination messages; about 17 hours to recharge.
  13. ↑ Malte Dehling, "VAXstation 3100 SCSI Terminator", GitHub repository README, github.com/mdehling/vs3100-scsi-terminator. Community source.
Retrieved from "https://wiki.retrotechcollection.com/index.php?title=VAXstation_3100_Maintenance_Guide&oldid=21786"