GE Speedtronic IC3600 Spare Parts: Mark I, Mark II and Mark VI Control Card Reference Guide

The GE Speedtronic turbine control system is one of the most enduring automation platforms in power generation history. First introduced as the Mark I in 1969 and evolved through the Mark II, Mark IV, Mark V, and the still-active Mark VI platform, Speedtronic systems control gas and steam turbines across power plants, oil and gas facilities, and industrial energy installations worldwide.

Despite their age, Mark I and Mark II systems remain operational in a substantial number of facilities globally — and the IC3600 series control cards that power them are among the most searched-for legacy industrial components in the market. This guide covers the key IC3600 board types, their functions, and the Mark VI IS200 series boards, with direct sourcing links for each part number.

Industrial Partner  stocks GE Speedtronic IC3600 and IS200 series control cards for Mark I, II, and VI systems — including hard-to-find and discontinued boards. Browse GE Speedtronic parts or request a quote.

GE Speedtronic System Overview

Mark I and Mark II: The IC3600 Platform

The GE Speedtronic Mark I and Mark II systems use the IC3600 series modular control card architecture. Each card performs a specific logic, power regulation, relay driving, or I/O function within the turbine control system. The IC3600 cards are backplane-mounted in card racks and are directly interchangeable within their functional categories.

Although the Mark I and Mark II systems are fully obsolete from a manufacturing standpoint, they remain in active operation in many facilities due to their proven reliability and the cost of full system replacement. This means the IC3600 spare parts market remains active — and genuine replacement boards are increasingly difficult to source through standard channels.

Mark VI: The IS200 VME Platform

The GE Speedtronic Mark VI, introduced in the 1990s, replaced earlier systems with a VMEbus-based architecture using IS200 series boards. The Mark VI uses a modular rack containing a main processor card, VME communication interface (VCMI), and dedicated I/O boards. It remains the most widely installed current-generation Speedtronic platform in gas turbine and steam turbine applications.

IC3600 Series Control Cards — Part Number Reference

The following IC3600 series boards are among the most frequently searched and sourced spare parts for GE Mark I and Mark II Speedtronic systems:

Power Regulation Boards

•       IC3600EPSX1  —  N12 1.5A Voltage Regulator Card — regulates the negative 12V supply rail in Mark I/II systems

•       IC3600SVDC1  —  Servo Drive Control Card — controls servo valve drives in the turbine fuel control circuit

•       IC3600AVSD1  —  Analog Voltage Summing and Distribution Card

 

Input and Signal Buffer Boards

•       IC3600LIBA1  —  Input Buffer Card — buffers logic input signals in the Mark I/II control system

•       IC3600LINA1  —  Light Indicator Card — drives indicator lamps on the Mark I/II operator panel

•       IC3600LTGA1  —  Logic Trigger Gate Card — provides gating functions in the logic chain

•       IC3600LSOC1  —  Logic Selector Output Card

 

Relay Driver and Output Boards

•       IC3600LRDC1  —  Relay Driver Card — 100mA relay driver, one of the most common replacement cards in Mark I/II systems

•       IC3600SFKC1  —  Servo Function Control Card — functions within the fuel control and valve management circuits

•       IC3600KMRD9  —  Medium Duty Relay Card — used for contact output functions in Mark I/II control logic

 

Additional High-Demand IC3600 Boards

Other widely sourced IC3600 boards from Industrial Partner's inventory include the IC3600LSOC1 (Logic Selector Output Card), IC3600AVSD1 (Analog Voltage Summing), IC3600LTGA1 (Logic Trigger Gate), and the IC3600SVDC1 Servo Drive Control Card.

GE Mark VI IS200 Series Boards

For facilities operating GE Mark VI Speedtronic systems, the IS200 series boards are the primary spare parts category. These VME-format boards perform dedicated I/O, communication, and processing functions within the Mark VI control module rack.

IS200AEPAH1A — Analog I/O Board

The IS200AEPAH1A is a GE Mark VI analog I/O board used in Speedtronic turbine control applications. It handles analog process input signals and is one of the most commonly sourced IS200 replacement boards. Compatible with both simplex and triple-redundant Mark VI configurations.

531X171TMAABG1 — Mark V/VI Interface Board

The 531X171TMAABG1 is a GE Speedtronic board used in Mark V and transitional Mark V/VI control systems. It serves as a termination and interface board connecting field I/O signals to the control processor rack.

DS3800NFCB — Mark IV Regulator Board

The DS3800NFCB is a GE DS3800 series board used in Mark IV Speedtronic turbine excitation and control systems. It is widely deployed in older gas turbine installations and represents one of the more frequently sourced legacy GE turbine boards.

Why GE Speedtronic Spare Parts Are Difficult to Source

The IC3600 series was manufactured from the late 1960s through the 1980s. GE Fanuc (now GE Vernova) has long since discontinued production of these boards, and the authorized distribution channel for IC3600 parts effectively does not exist for new stock.

The same challenge increasingly applies to IS200 series Mark VI boards — as the platform ages and OEM support contracts expire, facilities find themselves needing replacement boards that are no longer available through GE or its authorized distributors.

What this means in practice: when an IC3600LRDC1 relay driver card fails in a running turbine system, the maintenance team cannot simply order from the OEM. They need a specialist industrial supplier with genuine legacy inventory, the capability to verify board condition before shipment, and the technical knowledge to confirm compatibility.

Industrial Partner  maintains active inventory of IC3600 series boards and IS200 Mark VI components for GE Speedtronic systems. Fast sourcing for urgent turbine maintenance needs. Browse Speedtronic parts or contact the team for urgent requirements.

Maintenance Guidance for GE Speedtronic IC3600 Systems

Handle All IC3600 Boards as ESD-Sensitive Components

Every IC3600 board must be handled with full electrostatic discharge precautions — grounded wrist strap, antistatic mat, and antistatic packaging for storage and transport. Even boards that appear functional can be damaged by ESD events that are not immediately detectable but cause latent failures under operating conditions.

Verify Board Revision Before Installation

IC3600 boards were produced across multiple manufacturing revisions. While most revisions are functionally compatible, some later-revision boards have component changes that affect their behavior in early rack configurations. When sourcing replacement boards, confirm the revision designation (e.g. IC3600LRDC1 vs IC3600LRDC1A) is compatible with your specific system revision.

Maintain a Current Card Inventory Register

For any facility operating a Mark I, II, or IV Speedtronic system, maintaining a complete register of every board type and quantity currently installed — along with at least one spare for each critical board type — is essential operational practice. The sourcing window for many IC3600 boards is narrowing as global secondary market inventory depletes over time.

Conclusion

GE Speedtronic IC3600 and IS200 series boards represent some of the most critical and hardest-to-source legacy spare parts in the power generation and gas turbine maintenance market. For facilities running Mark I, II, IV, or VI systems, proactive spare parts sourcing before a board failure forces an emergency procurement event is the only reliable strategy.

Industrial Partner maintains genuine IC3600 and IS200 inventory for immediate dispatch, with the technical capability to confirm board compatibility and condition before shipment.

Need GE Speedtronic boards urgently?  Browse IC3600 and IS200 Speedtronic parts at Industrial Partner or contact the team for same-day availability confirmation.