Thanks for the status on your project. I figured I would start new conversation since the original was “closed by solution”.
I am curious if you, Barry (@MicroChemist), or anyone else out there who has one of these microscopes have found a cable wiring diagram for the FXA / FXL control/power cable? I have a PSM-4A supply that I picked up on eBay a few months ago. Very interested if the cable you have is a straight-through type (pin-to-pin) between the connectors? If that is the case, I can build one to test the power supply.
I have an interesting conundrum here. I purchased a FXA from eBay for $250 in Dec '24. The seller shipped it to me in the most unprotected cardboard box, using old present wrapping paper as cushion filler. Was very disappointed when it arrived! Especially, since I was charged $165 for shipping. The “bio hazard” label on the box may have encouraged the shipping folks to expedite the box out of their eyesight as rapidly as possible. Note how the base of the instrument is protruding through the hole in the box.
Sure, I purchased it knowing it was a “Parts Only” unit and expected it would have its challenges. Had to start with something. Surprisingly, not much damage to the optics. The binocular assembly had a broken prism and there was some cosmetic damage to the selector buttons on the focus assembly. I found a replacement Binocular and another filter cassette because the original had some non-moving parts.
A month or two later, another FXA was posted for about the same price (different vendor, thankfully). It arrived with much better attention to packaging and shipping.
I know there are a lot of options for this model. These two have some differences between them including the base electronics interface panels. The first one shipped to me has a DB-25 connector for power input and a 4-pin circular for the Mercury Light Source Housing. But the second one is actually older and it has the SUMICON Rectangular Connector.
I like where this is going. I’d love to get mine working, like, really badly!
The PSM-1 unit and cable that I have (uselessly) are a straight through 1-1 connection through the SUMICON cable.
The 26 pins go from the PSU to the back of the scope with no funny-business.
When turned to face each other, 1 rings continuity to 1, 2 to 2 etc.
This means we actually don’t need old school SUMICON plugs, I’d actually be happy to terminate a more readily available 26pole terminal if we can’t get SUMICONS. (I regularly make wiring looms for comms and HV components and could definitely do a neat job but would need to alter the back of our scope bodies and PSU).
Alternatively we could make a straight through cable from the SUMICONS if we can find them.
The design of the power supply and microscope are integral components to each other. Without a schematic for both, it has been an interesting challenge to map the signals between them. There are feedback circuits from the microscope that unlatch safety circuits and switch source voltages in the power supply, as well as sense circuits on the power supply side that respond to signals from the instrument. Not an uncommon design feature, when distributing multiple voltage and current sources.
I have opened both units and have been tracing the signal paths between the boards. Unfortunately, an interface cable will be necessary to complete the survey. Ordered some connectors/crimp pins to construct a harness. They will be here in the next few days.
Yes, that is an excellent find with both M and F terminations and two shells. The scope does use the (M) connector and an (F) on the PSM-4a. So the kit you have found seems to be a good choice. The part numbers align fairly well with what I ordered. The only major difference is the connector shell type. The ones I ordered below have a CA(50) which is different in how it latches onto the stopper bracket. You may need to get a second stopper bracket to complement the kit. I would also recommend looking for a kit that contains the CA(50) variant.
I hesitated to post the part numbers until they arrived (today) to ensure I had ordered the correct ones.
I am using crimp pins, so I can reconfigure pin assignments if necessary. I have 24AWG multistrand wire and sheathing mesh from another project. Will be assembling the harness over the next two evenings, since my extended holiday is over and I return to work in the morning. Should have an updated wire diagram by Sunday.
Have you opened the PSM-1 unit, and looked at the board layout? Could you tell me the board manufacturer and nomenclature, please? The PSM-4a uses a SANDEN S-PS-0216 board and utilizes 33 of the 34 pins on the Control Connector. If the PSM-1 uses same board, there is a chance it could be converted to emulate the PSM-4a. I have been keeping an eye out for another PSM-4a, unfortunately, they are becoming scarce.
Honestly, I am not confident the one I have is functional, yet. The signals and source voltages are not what I had expected. Although, I suspect it might be due to the unbalanced circuits without being integrated with the scope.
