Testing a remote control receiver sensor

[selectaircon]

Is there any way I can test if a remote sensor is working?
I've been asked to look at a multi splt inverter where one of the indoor units is not responding to any command from the remote control.

The remote control works on the other indoor unit. There is a reset button on the remote but its still not working.

The manual button situated on the indoor unit does appear to work.

To confuse things further, its a six year old bespoke model that was commisioned by quite a large installation company on the Costa Blanca within Spain that no longer trades. Therefore, I can't get parts.

Basically, what are the most common faults for the receiver?

Mark

[AbsoluteWDJ]

1. Check the plug/wire from receiver onto indoor PCB.
2. Swap around with the receiver from the unit that works.

[frank]

Does the green light just slowly flash on the one that doesn't respond?

This happens if the indoor units 'Mode' doesn't match the 'Master' mode. i.e. if the master indoor fancoil is in cooling mode but the slave is in heating, the slave will just flash the green LED as it can't do any work until the outdoor is commanded to cooling mode.

[selectaircon]

Can't believe I didn't think of swapping the boards with the one that works (must be getting old). There are no LED lights when using the remote, but the green operation light comes on as normal when using the units manual button. I'll check the modes anyway.
Thanks Mark