Cami Research M4 Cable Tester Teardown
I wanted a Cami Research M4 Cable Tester for personal use. I have a M3 and had an M4 on my watch list for some time this one popped up on the feebay and it was reported as dead. These m4 cable testers are sought after by personal users and business as they are exceptional in their capabilities. A lot of tech’s like my self use our personal test equipment in the shop.
What Is the CAMI Research M4?
If you’re not familiar with the M4, it’s one of the most capable cable testers on the market. These aren’t the average $30 continuity checkers you find at a hardware store or the $500 aliexpress specials. The M4 is a professional-grade, modular cable testing platform used by manufacturers, defense contractors, aerospace, electronics technicians, and hobbyists (when they find them on the secondary market) who needs to verify complex wiring harnesses and cable assemblies with precision.
A brand New M4, you’re looking at roughly $4,500-$5500 for the base M4 unit. The price is not listed CAMI is one of them companies ya have to call and ask. What do they say? If you have to ask ya cannot afford it. The AEX Add-on modules run around $1,300-$1,500 each, and the adapter sets add another $300 to $400 per connector type. I have a post on the Cami Research Adapter PCB Footprint so you can make your own. If you have the pinmap or build options. A fully loaded M4 system can easily push well past $10,000 for testing common cables. These are not impulse purchases they’re capital investments.
Which is exactly why the used market for them is so active, and why a “dead” unit at a fraction of that price is worth a serious look. Sometimes the liquidators don’t even actually power them up they just list them as dead or untested.
Here is the Ebay Listing Screen Shots! Bonus this one has the M4-AEX and some boards with Microsoft printed on them?? Will need to research these!!
Description Noting this has issues. “Unit Does Not Power On?”
(Cami Research CEO Christopher E. Strangio in his own words states he don’t like the idea of buying these used and broken fixing them and making a profit) that is a massive FTC Violation will they ever enforce it? probably not! Cami CEO’s intent is to “close off business opportunity for independent repair shops” directly describes what Strangio is doing that the FTC policy on deceptive trade practices are there to prevent.
Cami Research has this anti right to repair statement on their site now… 100% yea we violate the law!
RCW 19.415.010(11) defines “Owner” as: “an individual or business that owns or leases digital electronic products purchased or used in this state.”
The obligation for original manufacturers to make parts, tools, and documentation available applies to products “first manufactured, and first sold or used in Washington, on or after July 1, 2021.” So the coverage question isn’t just about who owns the product now, but whether the product itself meets the geographic/temporal nexus when it first entered commerce in Washington state. I will be making another request if denied another report to the AG’s office with full evidence of manufacture date and the date it entered WA State.
June 02 2026 Box Arrived.
Box was rather large.. and Cottie Kitty Cat had to make it hers as Always.
Lets unbox it and take it apart see what all the secrecy is over the internals of the device compare it to the M3U and attempt to back up the firmware (Most Likely Locked). I am sure cami Research will black list the serial numbers of this unit.
Item was very well packaged… top notch seller.
Regardless I am a little bummed out that the thing powered on and passed the self tests? So no repair content.
I will still e-mail Cami Research and ask to buy a few of the posts they prob will not sell them all else fails can have them machined or 3d print some.
Internal Photos.
Main Board
MCU is the same Sill Labs 8051F342 that is in the M3U (FPX)
I will be doing a live stream on the backup of the attempted firmware backup of the Cami Research Cableeye M4!
Cami Research M3Z M4 AEX Expantion Board Revision 6.1
The Microsoft Boards? Not Sure what system or product these are used for?
CAMI Research Right to Repair Score: D-
No Schematics, No Bill Of Material, No Service / Error Code Description, No Calibration Tools For After Repair Calibration, CEO Said He Don’t want shops or customers repairing Second Hand Units! Reason why Not a “F” is when given an error code told what part failed but it took a lot to get that.
Last Updated on June 3, 2026 by Steven Rhine