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Allen-Bradley 1756-L74 ControlLogix – Repair Service Available

Allen-Bradley 1756-L74 16 MB ControlLogix 5570 controller. NJT Automation offers mail-in repair for the 1756-L74 with a 1-year warranty; replacement pricing is available on request.

Mail-in repair available now. Returned with a 1-year warranty. Replacement pricing on request.

Allen-Bradley 1756-L74 ControlLogix 5570 controller, 16 MB – front view
Request Replacement QuoteRequest Repair QuoteEstimated $1,440.00
Part Number1756-L74
Price
On Request
Previously sold for $1,149.99 - $2,599.99 USDAvailability and condition determine final quote.
DescriptionControlLogix 5570 controller, 16 MB.
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
Included
1 year, full-function
2 years
+15% of product price ($172.50)
3 years
+25% of product price ($287.50)
View full warranty policy
Returns
90-day free returns. View return policy
Exchange

Send us your defective 1756-L74 after your purchase for a 10% core credit. We also purchase old or damaged parts outright.

Availability
Available Level 1

This part is available through our Level 1 supplier network. Request a quote to confirm quantity, price, and next-day shipping options.

Inventory Level 1 RFQ

Level 1 parts come from vetted US suppliers we have worked with for years. Each unit is checked before it ships, so counterfeits, repackaged items sold as new, and worn-out equipment do not reach you. Every part carries the same NJT warranty and return policy as our own stock.

Request QuoteLearn more about Inventory Levels
Repairs

1756-L74 Mail-In Repair Service

Estimated: $1,440.00

How the Process Works:

  1. Submit Your RFQ: Complete the request-for-quote (RFQ) form with your exact requirements.
  2. Receive a Quote: We respond ASAP - within 1 hour during business hours.
  3. Approve and Pay: Agree to the quoted price, and we will issue an invoice payable via credit card or your preferred method.
  4. Direct Shipping: Our normal shipping time is 3-5 business days, during which we thoroughly inspect and certify items to meet our high standards. If you request next-day air delivery, the item will be sent directly to you and arrive the following business day. Please note: These items are NOT available for local pickup at NJT Automation's location.

What We Offer

We source genuine parts from trusted U.S. channels and stand behind what we sell.
  • Our network has millions of parts ready to be delivered now.
  • Complete Transparency: Clear information on item availability.
  • Well-vetted components from trusted suppliers sourced from the USA.
  • Technical Support: Assistance, troubleshooting and hardware repairs.
  • Minimal Markup: The best sourcing service at a minimal cost.
  • Quick Delivery: Fast access to the parts you need to get your machines back up and running.
  • Dropship available • No branding on packaging

Part Number Decoder

ControlLogix 5570 controller
1756L74

16 MB ControlLogix 5570 controller.

1756
BulletinControlLogix: Rockwell Automation's chassis-based control platform (controllers, I/O, communication modules, power supplies and chassis).
L
Module typeLogix controller (CPU module).
7
GenerationControlLogix 5570: Logix5570 series (USB programming port, SD card, energy storage module).
4
Memory size16 MB of standard user memory.
Decoded from the Rockwell Automation catalog-number structure. Series and firmware revision are printed on the product label, not encoded here.

Physical Data

Weight and DimensionsWeight0.87 lb (0.39 kg)H × W × D5.7 × 1.4 × 5.7 in. (145 × 35 × 145 mm)
Weight0.39 kg (0.87 lb)
Typical unit weight
Dimensions (H × W × D)145 × 35 × 145 mm (5.7 × 1.4 × 5.7 in.)
Single-slot controller module
Shipping Weight0.92 kg (2.03 lb)
Estimated: unit weight plus box and packing material; bills as 3 lb
Shipping Box (L × W × H)12 × 12 × 8 in. (305 × 305 × 203 mm)
Smallest standard box fitting the product with 3 in. cushioning per side
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.

Datasheet

Datasheet available for download
Generated from product specifications; not an official Allen-Bradley datasheet. For an official datasheet, contact Allen-Bradley or an authorized distributor.

Similar Part Numbers

  • 1756-L72 Memory size: 4 MB of standard user memory
  • 1756-L73 Memory size: 8 MB of standard user memory
  • 1756-L75 Memory size: 32 MB of standard user memory

Allen Bradley Information

Technical Description
16 MB ControlLogix 5570 controller.
Technical Specifications14 parameters from manufacturer-published specifications
Controller familyControlLogix 5570
User memory16 MB
I/O memory0.98 MB
Tasks32
Controller connections500
Embedded communication1 × USB (network access via 1756 communication modules)
Digital I/O, max128,000
Analog I/O, max4,000
Memory card1784-SD1 (1 GB SD, included)
Energy storage1756-ESMCAP energy storage module (no battery)
Backplane current800 mA @ 5.1V DC
Power dissipation2.5 W
Chassis slots1
Weight, approx.0.25 kg
Typical manufacturer-published values for this catalog number; confirm against the current manufacturer documentation before specifying.

Alternate Part Numbers

1756L74
CategoryControlLogix
Part Number1756-L74
ManufacturerAllen-Bradley

Previously sold 1756-L74

6 sold

NJT Automation has supplied and shipped 6 1756-L74 ControlLogix 5570 controllers since 2024; request a quote and we will source another from our supplier network.

Sold
6 since 2024
Price range
$1,150 – $2,600, median $1,800
By condition
Unused surplus (5)$1,500 – $2,600
Series
B × 5, A × 1

Unused surplus 1756-L74 ControlLogix 5570 controllers have sold for $1,500 – $2,600, typically around $1,800.

Allen-Bradley 1756-L74 Unused surplus (new old stock) - previously sold by NJT AutomationSold

2020 Allen Bradley 1756-L74 Ser B ControlLogix 16MB Processor Sealed Surplus

$2,599.99 USD

Unused surplus (new old stock)

Request Quote
Allen-Bradley 1756-L74 Unused surplus (new old stock) - previously sold by NJT AutomationSold

Allen Bradley 1756-L74 /B 16M ControlLogix 5574 Processor - 2024 Sealed Surplus

$2,099.99 USD

Unused surplus (new old stock)

Request Quote
Allen-Bradley 1756-L74 Unused surplus (new old stock) - previously sold by NJT AutomationSold

2022 Allen Bradley 1756-L74 Ser B ControlLogix 16MB Processor - Sealed Surplus

$1,799.99 USD

Unused surplus (new old stock)

Request Quote
Allen-Bradley 1756-L74 Unused surplus (new old stock) - previously sold by NJT AutomationSold

Allen Bradley 1756-L74 /B ControlLogix 5574 16MB Controller - Open Box

$1,799.99 USD

Unused surplus (new old stock)

Request Quote
6 sold on eBay

Can the 1756-L74 be repaired?

Yes. NJT Automation offers mail-in repair for the 1756-L74, including diagnostic evaluation, component-level repair, and functional testing.

NJT Managed Repair

One vendor. One warranty. NJT manages the entire process.

  • 1-year full-function NJT warranty, with 2- and 3-year options available
  • Rush service available for production-critical repairs
  • No evaluation or diagnostic charges
  • No repair, no charge
  • "Unrepairable" is not an option
  • Pre-paid UPS shipping label provided for sending your unit in
  • $650 minimum repair charge, shipping included both ways
Get an NJT Repair Quote

Looking for another option? For lower-cost repairs or if you prefer to work directly with an independent repair specialist, compare bids through RepairMode. RepairMode providers operate independently and set their own pricing and warranty terms.

Find a PLC repair specialiston RepairMode.com ↗

Common 1756-L74 failures

Failure patterns we regularly see on ControlLogix 5570 controller hardware like the 1756-L74:

  • Front USB port failure: Studio 5000 will not connect over USB
  • Scrolling status display blank or unreadable
  • Backplane communication faults from bent chassis pins after repeated module swaps
  • Program lost on power cycle: energy storage module (1756-ESMCAP / ESMNSE) failing to hold the controller through a save
  • Solid red OK LED (nonrecoverable major fault) that returns after clearing

Repair or replace?

ReplaceReplace the 1756-L74 if it will not boot, shows a solid red fault light, or has lost its program. Another ControlLogix 5570 controller takes the same program: download it, match the firmware, and the line is running again. Stick with the exact 1756-L74. The suffix sets the 16 MB memory, so a near match is a different unit. We source the 1756-L74 on request, so weigh that lead time against a repair turnaround.
RepairRepair the 1756-L74 when the fault is in the power section, a port or the status display rather than the processor core, or when the controller carries a firmware revision or validated project you cannot easily re-flash onto a different unit. Most 1756-L74 units reach our bench with one of two symptoms: “Program lost on power cycle” or “Solid red OK LED (nonrecoverable major fault)”. Already swapped it out? Repairing the failed 1756-L74 turns it into a tested spare on the shelf for the next failure. Our estimated $1,440.00 repair of the 1756-L74 includes full-function testing and a 1-year warranty.

Request a Repair Quote

Text photos of the faulty unit and the symptoms to (414) 331-5954.

Start Your Repair Today

All product photos were taken by NJT Automation. Test videos originated from either NJT Automation internally or from repair technicians within our network.

Still have questions?

Find answers to shipping, warranties, repairs, and more.

The Allen-Bradley 1756-L74 is a 16 MB ControlLogix 5570 controller.
The 1756-L74 is available in Unused surplus / Refurbished / Used condition. We can quote this part in unused surplus, refurbished, or used condition depending on availability and your preference. Specify your requirement in the RFQ.
At NJT Automation, 6 1756-L74 ControlLogix 5570 controllers have sold since 2024 for $1,150 – $2,600, with a median of $1,800. None are in stock at the moment; request a quote for current pricing, or have your ControlLogix 5570 controller repaired for an estimated $1,440.
This 1756-L74 is sourced on request, so sourcing and quote timelines apply. Request a quote and we'll confirm availability and lead time. Many parts can be sourced within a few business days through our Level 1 supplier network.
Yes. UPS Next Day Air is available at checkout for the 1756-L74 ControlLogix 5570 controller. Place your order before 5:00 PM Central on a business day and your in-stock item ships the same day for next-business-day delivery.
Yes. Once your 1756-L74 has been sourced and is ready, free local pickup is available at NJT Automation, 2122 N Prospect Ave, Milwaukee, WI, during business hours.
16 MB of standard user memory.
NJT Automation

NJTAutomation

Industrial Electronics

Supply & Repair, Milwaukee WI

(414) 331-5954EmailRequest a quote

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Product Condition & Warranty

Products sold by NJT Automation may be surplus inventory, discontinued models, older series, or units with earlier manufacturing date codes than those currently available from the OEM or its authorized distribution network. As NJT Automation is not an authorized distributor, manufacturer warranties, support programs, and other OEM services may not apply. Any warranty provided is solely that of NJT Automation, where applicable.

Firmware & Software Licensing

Certain programmable logic controllers (PLCs), drives, HMIs, and other electronic products may require firmware to operate. While some products may include firmware, NJT Automation makes no representations or warranties regarding whether firmware is installed, the firmware version or revision level, its compatibility with your application, or its licensing status.

NJT Automation does not provide, obtain, transfer, or license firmware on behalf of customers. We make no representation regarding your ability or legal right to obtain, download, install, or use firmware from the OEM, its authorized distributors, or any other source. It is the customer's sole responsibility to ensure compliance with all applicable End User License Agreements (EULAs), software licenses, intellectual property rights, and other terms governing the acquisition, installation, and use of firmware.

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