I've started seeing the cooler temperature creep colder over the course of several hours when controlled and viewed from TheSkyX Pro. This occurs independent of setting a small or large temperature differential. For example, setting a desired -30C might result in proper temperature regulation for an hour, and then BOTH the set temperature, and the camera temperature creep up to -34C an hour later with correspondingly higher cooler power levels. In the first instance of discovering this, an unattended session showed 100% cooling power in the morning, with the set and actual temperatures bottomed out around -45C as I remember. This STT8300 is of 2008 vintage, running the original power supply. Serial #T15070693.
I agree with Bill. The camera does not just suddenly decide to change it's cooler set point. This sounds like a software bug or system problem. What exact version of TSX are you running? e.g. TheSky Version 10.5.0 Build 13311 - 32-bit or 64-bit ? What about SBIG Driver checker? version 4.05 And the sbigudrv.dll shown by the SBIG Driver Checker? e.g. 5.1.1.0 If you use the Firmware tab in the SBIG Driver Checker, and Get Firmware Version from Camera, is it current? Try running the camera with other software, such as CCDOps 5.66 or MaxIm DL Pro 6.29, and check the behaviour.
