Allen-Bradley 1756-L61SEK ControlLogix Processor
Allen-Bradley 1756-L61SEK ControlLogix Processor. NJT Automation sources the 1756-L61SEK on request; send the part number for a replacement or repair quote.
Quote required. Request a quote below for pricing and delivery.

Actual NJT inventory photos
| Part Number | 1756-L61SEK |
| Price | On Request Availability and condition determine final quote. |
| Description | Allen-Bradley 1756-L61SEK ControlLogix Processor (ControlLogix Module). Key features: 2MB user memory, supports up to 250 controller connections, and includes a Secure Digital (SD) card slot. |
| Shipping | UPS Ground included | Next-Day Air and Worldwide Shipping available at checkout |
| Warranty | 1-year full-function warranty provided by NJT Automation. Warranty details
|
| Returns | 90-day free returns. View return policy |
| Exchange | Send us your defective 1756-L61SEK after your purchase for a 10% core credit. We also purchase old or damaged parts outright. |
| Availability | Sourced on request We do not have a 1756-L61SEK on the shelf right now. We can source one through our supplier network; request a quote and we confirm availability, price and lead time before you commit. | ||||||||
| Sourcing | Sourced through our Level 1 network of vetted US suppliers. Each unit is checked before it ships and carries the same NJT warranty and return policy as our own stock. Quotes within one hour during business hours; typical delivery 3–5 business days, next-day air available. Sourced parts are not available for local pickup. | ||||||||
| Repairs | 1756-L61SEK Mail-In Repair Service | ||||||||
Series & Revisions | Series A uses the 1756-BA1 battery; Series B uses the 1756-BA2. Firmware files are the same for both. Series notes: Studio 5000 keys on catalog number and firmware revision, not series; fit the correct battery for the series. | ||||||||
Intended Use | Designed for plant-wide discrete, process, and motion control applications. ControlLogix controllers run high I/O-count machines, batch and continuous process lines, and coordinated multi-axis motion from a single chassis, with redundancy and plant-network connectivity when the application calls for it. Typical homes are automotive and tire plants, food and beverage lines, water and wastewater, oil and gas skids, and large packaging systems. | ||||||||
Migration Path | Rockwell Automation has discontinued the 1756-L1, L55 and L6x controllers. Published successor for the ControlLogix 5550 / 5555 / 5560: 1756-L71 (ControlLogix 5570) or 1756-L81E (ControlLogix 5580).
A like-for-like replacement or a repair keeps the existing program, wiring and panel layout; a migration is a project. Both are listed on this page so the choice can be made on lead time and budget. | ||||||||
Physical Data | Weight and DimensionsWeight0.87 lb (0.39 kg)H × W × D5.7 × 1.4 × 5.7 in. (145 × 35 × 145 mm)
Product weight and dimensions are typical manufacturer-published values and may differ by series or option. Shipping box and weight are estimates for freight planning; the packed unit may ship in a different box. | ||||||||
Allen Bradley Information | Allen Bradley ControlLogix Controller 1756-L61SEK Key Features/Specifications: 2MB user memory, supports up to 250 controller connections, and includes a Secure Digital (SD) card slot. Technical SpecificationsLifecycle status
| ||||||||
| Category | ControlLogix | ||||||||
| Part Number | 1756-L61SEK | ||||||||
| Manufacturer | Allen-Bradley | ||||||||
Can the 1756-L61SEK be repaired?
Yes. NJT Automation repairs the 1756-L61SEK by mail-in: diagnostic evaluation, component-level repair and a functional test, backed by a 1-year full-function warranty.
NJT managed repair. No evaluation fee; no repair, no charge. Prepaid UPS label both ways, $650 minimum, rush available. 1-year full-function warranty included, 2- and 3-year options.
Compare quotes from independent repair technicians. Post your repair on RepairMode to receive competitive bids from experienced technicians. Each technician sets their own pricing and warranty.
Find a PLC repair specialiston RepairMode.com ↗Common failures
Failure patterns we regularly see on ControlLogix 5560 controller hardware like the 1756-L61SEK:
- Program lost on power cycle: battery (1756-BA1 / BA2) depleted, BAT LED red or flashing
- Battery-holder corrosion after a leaking cell
- Controller drops off the backplane intermittently: worn chassis connector or cracked board
- Front RS-232 serial port damaged from a hot-plugged programming cable
- CompactFlash (1784-CF64 / CF128) corruption: stored project does not load
Photos by NJT Automation; test videos from NJT or network repair technicians.
Still have questions?
Find answers to shipping, warranties, repairs, and more.