Open-Box DS3800HUMB1B1B: Same Board, Inspected Before Listing

This unit is new-surplus stock whose original factory box has been opened for inspection — the board itself is the same DS3800HUMB Universal Memory Board (UMB) used throughout the GE Speedtronic Mark IV control system. The UMB is the panel's non-volatile storage card: its EPROM/EEPROM modules hold the site-specific application program and control constants that the <R>, <S>, and <T> processors of the Mark IV's Triple Modular Redundant (TMR) architecture load at startup. Because the whole panel depends on this program data, UMB issues can show up as broad, seemingly unrelated control faults rather than a clean "memory" alarm.

The board is built for quick rack service — a modular connector on one edge and retention levers on the other allow removal and reinstallation without disturbing neighboring cards. A single red LED and a toggle switch (used to place the memory modules into an erase/reprogram state) sit on the front edge. The board's 30 jumpers, single-pin connectors, and module sockets are organized into four quads (A, B, C, D), and pin numbering restarts in each quad — a referenced pin is meaningless without specifying which quad it belongs to.

Rule These Out Before You Replace the UMB

Because this board underpins the entire panel's program data, it is frequently blamed for faults that have a different root cause:

• A loose modular connector or unlatched retention lever after other maintenance — reseat and confirm before assuming a hardware failure.
• A failing individual EPROM/EEPROM module rather than the carrier board itself; since the program lives on the modules, they are normally transplanted onto a replacement board's empty sockets.
• Unstable or noisy rack power causing intermittent checksum alarms that disappear after a clean power cycle.
• An alarm actually pointing to a companion board rather than the UMB — the single front LED is a general status light, not a detailed self-test.

Work through these first; if the fault persists and follows the board, replacement is justified.

Understanding the 1B1B Suffix

DS3800 identifies the Mark IV board series, HUMB is the Universal Memory Board function code, and the trailing "1B1B" marks a specific hardware/firmware revision. GE produced the UMB across several suffixes that are not automatically interchangeable, so match the exact suffix on your existing nameplate wherever you can, or ask us to confirm before ordering. Our GE Speedtronic Part Number Decoder explains the general structure of these part numbers.

Also Stocked: Companion Mark IV Boards

The UMB works alongside other Mark IV DS3800 boards such as the DS3800HFPG Drive Control Board, DS3800HMPK Microprocessor/Regulator Control Board, and DS3800NDAC Analog Output Board, all available in our GE Mark IV DS3800 Boards collection. For a broader view of GE turbine control hardware across generations, browse our GE Speedtronic Turbine Control Boards collection, or see our Mark V vs Mark VI: DS200 to IS200 guide if your site is planning a migration off Mark IV.

Before You Request a Quote, Gather This

• The full part number with suffix (DS3800HUMB1B1B)
• A photo of your existing board's label/nameplate
• Turbine model/frame and confirmation your system is Mark IV
• Quantity required
• Your urgency/timeline

Request a Quote for This Open-Box Unit

This DS3800HUMB1B1B is new-surplus, open-box (original box opened for inspection), cleaned and tested, and backed by a 1-year warranty. We ship worldwide DDP (Delivered Duty Paid), accept purchase orders, and turn around quote requests within 24 hours. Submit a Request a Quote and we will confirm compatibility with your turbine and panel first.

General Information about the Product
Part Number	DS3800HUMB1B1B Mark IV DS3800
Description	DS3800HUMB1B1B by GE General Electric DS3800HUMB Universal Memory Board OPEN BOX
Condition	newSurplusNoBox Cleaned and Tested. With 1 Year Warranty.