[DIYbio] Re: BioRad ICycler Password or Service Manual

This thread is pretty old, but the first result I found on Google. If your iCycler brings you the error message "Heat/Cool test fault Operation not possible" there should be eight sensor temperatures at the bottom of the display (here is a video of it: https://www.youtube.com/watch?v=KO6D1jgCa9c). They should all lie in the same range. So if five of them show 0°C and three of them show 22°C you probably have five faulty temperature sensors or the wire to the temperature sensor is broken. If you have two iCycler, you can try to swap the Well Reaction Module between them and see if the error is still there. If not you can meassure the sensors with a multimeter on the connectors J5 and J19, which lie under the fan (you have to remove the housing for this). There are four sensors on each connector. So you in total you have five pins, one pin for each sensor and all four share one return wire. At room temperature the sensors should be around 12k Ohm. If it has a high-impedance, you found your faulty sensor circuit.

To fix it you probably have to screw open your Well Reaction Module or check your cable connections. Can't help you right now with fixing it, because I'm still wating for the screwdrivers I ordered to open the module...

Best of luck to you!

Lief