The DS3800DEPB1A1A is an excitation power board from GE's Speedtronic Mark IV (DS3800) generation of printed circuit boards. It does not run turbine sequencing, fuel staging, or protection logic; its label places it on the excitation side of the turbine-generator package, tied to the LCI (Load Commutated Inverter) exciter equipment that energizes the generator field. This listing covers a used board that has been cleaned and tested before it ships.

Where the DS3800DEPB1A1A sits in a Mark IV machine

In a GE Speedtronic Mark IV system the triple-redundant control cores <R>, <S> and <T> issue the commands that regulate generator excitation, while a board like the DEPB lives downstream in the exciter power stage that conditions and distributes that energy. The card carries a permanently attached 20-pin ribbon cable that seats it into the drive rack, plus five 10-pin ribbon connectors — often marked with IDs such as JA-RUN, CAL1B and JB-COM — that link it to the surrounding excitation circuitry. Two trimmer resistors and a small group of component terminals allow the board to be calibrated to the installation. Like every DS3800 card it is static-sensitive, so handle it by the edges with proper ESD precautions.

Prove the board is the problem before you order

Excitation faults are deceptive. A loss-of-field alarm, an exciter lockout, or an unstable field-current reading can originate anywhere in the chain — the exciter power bridge, field wiring, fuses, the shared power supply, or a companion board — well before the DEPB itself is to blame. Work outward from the simplest causes first:

• Confirm that incoming power to the drive and exciter is present and within tolerance.
• Check that the fixed 20-pin ribbon is fully seated; a ribbon that has crept loose imitates a dead board. Press firmly and look for any gap at the connector.
• Verify the five 10-pin ribbon cables are on their correct connectors and were not swapped during earlier maintenance — five identical-looking sockets make this a frequent false alarm.
• Inspect the two trimmer resistors and the component terminals for signs they were disturbed, and scan the board for heat discoloration or damaged parts.
• Compare against the neighboring excitation boards and the shared supply before you condemn this card.

Only once those items check out should you treat the DEPB as the failed component.

Decoding DS3800DEPB1A1A: function letters and group code

The part number breaks into three meaningful pieces. DS3800 identifies the Mark IV printed-circuit-board series; DEPB is the four-letter function code for this excitation power board; and the trailing 1A1A is the group/revision code that pins down the exact hardware variant. When you replace the board, match that trailing group code to the card you are removing or confirm compatibility with us — a 1A1A and a 1A1B differ only in the final group digit, usually a minor revision, but it is worth verifying. For a full walk-through of the scheme, see our GE Speedtronic Part Number Decoder.

Related excitation-side boards

The DEPB is one of several DS3800 DE-series excitation cards. It is frequently cross-referenced with the DS3800DECA LCI exciter control board, and it shares a rack and power source with other excitation components — which is precisely why confirming the correct function code (DEPB versus a neighboring DE card) matters before you buy. Browse the wider family in our GE Mark IV DS3800 Boards collection, or step back to the full GE Speedtronic Turbine Control Boards range.

Details that get your quote answered in 24 hours

To match the right board quickly, send us:

• The complete part number including the group suffix (here, DS3800DEPB1A1A).
• The revision printed on the board label — a clear photo of that label is ideal.
• The turbine and exciter model, plus the Speedtronic (Mark) generation the board serves.
• Quantity needed, and whether this is for a unit that is down or a shelf spare.

Request a Quote and our team replies within 24 hours. We ship worldwide on DDP terms, accept purchase orders from qualified accounts, and can advise on cross-compatible revisions when your exact group code is scarce.

General Information about the Product
Part Number	DS3800DEPB1A1A Mark IV DS3800
Description	GE General Electric DS3800DEPB1A1A DS3800DEPB LCI Excitation Control Board
Condition	used Cleaned and Tested. With 1 Year Warranty.