Marked DS3800DEPB1A1B, this board is the excitation power card in GE's Speedtronic Mark IV DS3800 line. The trailing 1A1B identifies a specific revision within the DEPB family, and this listing is a used example that has been cleaned and tested and carries a one-year warranty.

The DS3800DEPB1A1B excitation power board explained

Unlike the turbine-sequencing and protection cards people often picture when they hear Speedtronic, the DEPB works on the excitation side, associated with the LCI (Load Commutated Inverter) exciter equipment that supplies the generator field. Its physical layout is distinctive: a fixed 20-pin ribbon cable forms the permanent tie into the drive, and five 10-pin ribbon connectors branch out to the excitation circuitry around it. Connector IDs such as JA-RUN, CAL1B and JB-COM appear on the ribbon headers, and two trimmer resistors plus a handful of terminals provide calibration and component mounting. It is an ESD-sensitive card and should be handled accordingly.

Diagnosing an excitation fault without guessing

When the excitation system misbehaves, the board is only one suspect among many. Before ordering a replacement, spend a few minutes ruling out the surroundings:

• Power in: verify the supply feeding the exciter and drive is present and stable. A sagging rail can look identical to a board failure.
• The 20-pin ribbon: make sure it is fully home in its socket, with no gap that would indicate partially engaged pins.
• The five 10-pin cables: confirm each is on the correct header and none were swapped during prior work.
• Calibration parts: check that the trimmer resistors have not been turned and that no terminal component is cracked or scorched.
• Neighbors: compare notes with the companion exciter boards and the shared power supply.

A methodical pass through that list routinely finds a cable or supply problem masquerading as a dead DEPB.

Why the 1A1B group code matters when you order

The number decomposes cleanly: DS3800 is the Mark IV board series, DEPB is the excitation-power function code, and 1A1B is the group/revision suffix. That final suffix is the part that changes between otherwise similar cards; the safe practice is to match the group code to the board being removed, or to ask us to confirm whether a 1A1A and a 1A1B are interchangeable for your panel. Do not assume they are. The GE Speedtronic Part Number Decoder breaks down every field so you can read a full number with confidence.

Boards that work alongside the DEPB

Because the DEPB is part of a broader DS3800 excitation set, it is commonly seen with the DS3800DECA LCI exciter control board and other DE-series cards sharing the same rack and supply. Confirming you need the DEPB function specifically — not a neighboring exciter card with a similar number — prevents a costly mismatch. See related stock in the GE Mark IV DS3800 Boards collection and the broader GE Speedtronic Turbine Control Boards catalog.

Request a quote on this board

To turn your inquiry around within 24 hours, tell us:

• The exact part number and suffix (DS3800DEPB1A1B).
• The revision and any codes on the board label — a photo speeds things up.
• The turbine, exciter, and Mark IV panel the board belongs to.
• Quantity and urgency, including whether a unit is offline.

Request a Quote and we will respond within a day. Orders ship worldwide on DDP terms, purchase orders are accepted from qualified customers, and we can flag compatible revisions if the 1A1B is temporarily hard to source.

General Information about the Product
Part Number	DS3800DEPB1A1B Mark IV DS3800
Description	GE General Electric DS3800DEPB1A1B DS3800DEPB LCI Excitation Control Board
Condition	used Cleaned and Tested. With 1 Year Warranty.