Fluke Microscanner Pro remote unit

[Ranayna]

Hi everyone,

i have a faulty Fluke MicroScanner Pro.
The unit was in service for now many years, and apart from once breaking a pin on one of it's RJ45 plugs, it worked flawlessly over the years.
But now it developed an error that caused quite some extra work. Because it always showed an error on two wires  It took me quite some time to realize that not my crimping skills failed, but the tester 

I was not able to get the error on a picture, but it showed a fault on pair 3/6. Not open, just "Fault" with 3 and 6 blinking.

I took apart the remote unit, an immediatly, even before i saw the fault, i *smelled* it:


That poor resistor got *toasty*. I assume that the unit was connected to non-Standard Power over Ethernet. Otherwise i have no idea what could have caused that.
After i removed the resistor, the error on the main unit changes to "Open" at 3 and 6.

Now i have no idea though what value the charred resistor had. If i just short it, the main unit shows a short between 3 and 6.
Since the other resistors are all different, i strongly suspect that i need a specific value as replacement.
I also do not want to tinker too much with different values, because the pads and a trace directly below the resistor are already lifted.

I was not able to find teardown pictures of the remote unit, let alone schematics. Any ideas what that value could have been?

[Ranayna]

No one? I guess i will have to start tinkering

There is only one thing i can be sure of: The value has to be different than R1, R3 or R4, so that the main unit can detect a switched pair.

Next assumption: Since R1, R3 and R4 are all in the E24 decade, i think R2 likely is as well.
Further assumption: Since R1 is low, something suggests that R3 might also have been low.
Final assumtion: There is some logic in those values.

Concluding, i suspect that 300 Ohm might be a value worth trying...

[2N3055]

MAybe this can help?

https://www.eevblog.com/forum/projects/reverse-engineering-the-fluke-wireview-identifiers/

[Ranayna]

I found that topic while searching for schematics. These remote units look very different, and they also serve a different purpose than mine.
And while the Microscanner Pro has similar identifying remotes available, i do not have these, so i cannot compare.

I totally missed the Question about the Microscanner 1 on the last page though. Sadly unanswered

I will fiddle around with values this or next evening. But i do not have a 100 meter ethernet run available to properly test the values.