OK – answering my own question. The B unit has a bigger fan than the OEM “A” unit. The attached photo shows the old one on the left and the new one (already connected) on the right.

As it was, the OEM did not fit very well either. It was *very* difficult to get it out of the case.

To get the new one in I decided to cut off piece of the circuit board, remove two of the screws holding the fan on and file down one corner of the PM unit.

The result is shown in the last photo where some white space is left so you can see how it fits. It is quite impossible to mount the PM unit on top of the PCB, as both the -A and B versions are the same height as the enclosures. I have no idea how uRad was able to get the PM unit in there originally.

It has been running for a bit over ah hour now and looks like it will be OK.

Regards
Ken

Yes.

But your picture is out of date. The sensor you can buy today does not fit. And whoever assembled my unit originally simply jammed the sensor on top of the board.

Modifications I show in my photos will allow using the new sensor without forcing it.

But, basically, you have a problem with the current production run.

Ken