I have the above installed and sadly the on/off switch no longer works. Can this be replaced “simply” and if so would anyone care to suggest a shop to do it? Is there a direct plug in replacement for this unit?
Thanks
Replacing the on-off switch is a no-brainer, but are you sure it’s really the switch and not, for example, a blown fuse within the unit, or a broken wire on the connector, or anything else? Need to diagnose the problem first.
The switch no longer powers the unit to on and there is no feeling of the button leaving the “indent” when rotating. How does one diagnose the possible fault(s)?
Do we still have anyone in UK that will repair?
You mean the pot+switch? They are mostly chinese. You can test it by putting a meter on the switch. I have a KR87 at home and will take a look.
Fenland_Flyer wrote:
The switch no longer powers the unit to on and there is no feeling of the button leaving the “indent” when rotating
The part in question is a potentiometer with switch. The maintenance manual for KR87 lists it as 031-00353-0000, but I’m sure it would also have a non-aviation model number, which would be cheaper and easier to get. This is what it looks like:
One needs to get close-up and google the numbers. Everybody and their dog in China makes these, or something very similar. There is obviously no need for the same PCB pin spacing; it can be wired-in.
The pot in mine is actually marked 00353-0000 so looks like a King custom part. A google on
switched potentiometer 00353-0000
digs up several hits, including one at $85. And this curious one.
There are some on Ebay which look very similar.
I’ve uploaded the KR87 MM here and that will tell you the pot value.
Peter wrote:
I’ve uploaded the KR87 MM here and that will tell you the pot value.
It won’t. It’s listed as S401/R413 in the drawing, but only as S401 in the BOM, which says 031-00353-0000 and nothing else.
True; just done OCR on that PDF. But you can measure the pot.
Curiously I could not find the pot or the switch in the MM circuit diagrams.
This is a photo showing key dimensions
Looking at the knob size (about 7mm dia) I would expect the pot shaft to be 1/8" or 3mm.
