I recently posted about the CGEM hand controller going blank. After speaking with Celestron tech support I discovered that this is not a rare problem with these HC's. It seems that if you live in an area with moderately high humidity you need to cover the HC with something to keep the humidity from invading the HC and shorting out the electronics. This is straight for Celestron. You can also attach a dew heater to the back or use a cover case for the HC. I found them at Scope Stuff. Needless to say I ordered a case for mine. Just a little info for all.