I have an un-usual problem with some sort of electric charge on my gear. I need some advice on tracking it down. This is on an imaging setup on a concrete pier in my observatory, CGX mount, MN190 scope, ASI1600MM-C camera, Starlight Express filter wheel, MBeat 7 port powered hub, ZWO guidescope and ASI290 guide camera. Heater straps on the MN and guidescope are powered by a Kendrick contoller with source from a 12V battery. All other devices are powered by 12V from two AC/DC power supplies, except the Mbeat and USB3 cable extension which run off AC plug packs ( output 5V). The pier top plate is not earthed but this setup has been running for three years without any issues, and the mount (with different scope and camera) was out at Mangrove Mountain the night before without any issues.
When touching the focuser knob I receive a small shock (consistent with a 12v supply being applied somewhere), in fact touching any part of the gear, scope and mount I receive this small shock. This is not normal. This stopped my imaging last night because it also seems to affect the ASI1600 ability to download an image to SGP, with SGP going into a loop trying to download but failing to get anything. The CGX PWI mount control software running on the laptop failed at the same time with an 'exception error'.
Any ideas on how to debug this in the daytime?
I will take my multimetre out and try to measure the potential, and probably disconnect one power supply after the other, and one accessory after another. Has anyone had something like this happen?
