Last Saturday our observatory had a nearby lightning strike, my PC, Esatto focuser, and SiTech mount controller are dead, my IP power switch no longer works and the display shows gibberish, my STT-8300 has a light that comes on when you apply power, but no fans. I have not yet tried to connect it to a working PC as I didn't have a spare with me at the time. I'm guessing the camera is fried, however I do have a spare identical camera to use. My main question is this, if I plug in my filter wheel/AO unit, if they were damaged as well is there a possibility they will damage the good camera? I have a spare filter wheel and AO unit as well, but I would like to know if my current AO/filter wheel are still good. I know this camera doesn't have much value, do you have any parts for these left to repair them? How much would a diagnostic charge cost if I sent it in? And slightly off topic, but if anyone has any suggestions on how to help prevent this down the road I would appreciate it. Interestingly my observatory partner as far as we can tell so far had no damage to his equipment at all. The only real difference is his pier is completely concrete while mine is steel then bolted to a concrete base in the ground. Our best guess is there was a ground charge that came up through the pier, my mount controller and DC power supply were mounted directly to the pier, and then the charge spread from there across the USB grounds? The only other damage we have found in the observatory is the ethernet connection on the PC that stays on 24/7 stopped working, but the PC itself seems to be fine. I do plan on trying to isolate more of the electronics from the pier but I see no real way to isolate everything without compromising rigidity. Thanks
Damage to the filter wheel / AO is unlikely unless this was a direct strike on the observatory. Most likely the USB port on the STT main board is blown. We no longer have a supply of replacement parts for the STT cameras. Replacing the USB chip is theoretically possible, but there may be other damage to surrounding components so I wouldn't give it a high probability of success. About the only thing we could do is transplant your sensor into a new Aluma CCD body. A direct strike on the observatory will probably destroy everything, but most strikes are indirect. A strike hits nearby and induces enormous currents into the ground, which can cause thousands of volts of potential difference across a short distance. If you have two pieces of equipment separated by a few feet, both connected to ground at their location, then you can get enormous currents going through the cables between them. Zap! The key to surviving an indirect strike is to have NO distance between the grounds of your equipment - bring all the grounds together at a single point. In the case of an observatory, this should be the pier. In my dome, the electrical connection comes in at the pier, and the electrical safety ground connects directly to it. Everything else is tied to that single point ground. Since I've taken that approach I haven't had (knock on wood) any lightning damage. My other piece of advice... if you're not going to use the observatory for a while, unplug all the cables.
Doug, thanks for taking the time to reply. I'm curious, and maybe I'm just not understanding, but how do you tie together a ground to a DC device that doesn't have a ground? Do you know of any resources I could read over that would help me better understand this? Since I have a backup STT camera I'll just switch to that, while transplanting the chip to an Aluma body sound interesting, I would have to wonder if that money would be better spent towards a CMOS chip instead? How much of an improvement are the Aluma electronics over the STT? Would my filter wheel and AO8 work with the Aluma?
Joshua, Even DC powered devices typically have a ground. In the case of an STT camera, the shell is ground. If all else fails, the DC minus side can be grounded. The Aluma is faster than the STT and makes very clean images. The AO just needs a different connector, but the filter wheel is mechanically different. There are pros and cons to CMOS cameras - you'll get different opinions from different people. The SONY sensors are the cleanest. If you want to switch to CMOS, my go-to would be the Aluma AC455.
