About a year ago, I bought my longtime dream scope. A CPC 1100 Deluxe. I already had some AUX bus accessories to go with it: a 4x Dew Header Controller, Focus Motor, and StarSense Autoalign. Everything worked just fine together with a hand controller. Then I discovered that Celestron announced StarSense Autoguider, the thing I always wished Starsense Autoalign would be. I had a shut up and take my money moment and preordered it. My StarSense Autoguider arrived in mid-July. I updated firmware to make sure my gear was compatible, connected everything, and was greeted by errors 16/17 and a mount that started slewing and stopped responding to the hand controller. Basic troubleshooting revealed that my scope worked properly only if I left one AUX device disconnected. I sought help here and filed a support ticket with Celestron in late July.
My experience with Celestron customer support was interesting. I didn't expect them to be as responsive as they were. We went back and forth by email for a while looking at different cables and power supplies with no effect. Then one day I received a phone call from Celestron, indicating that I had made it to a higher level of their customer support. They sent me a hand controller with a custom firmware to fix what they had observed as a problem elsewhere, which didn't fix anything. Eventually they asked me to send in my CPC and AUX accessories for their engineers to properly investigate the problem. Recalling some horror stories I saw here, I reluctantly agreed. I boxed everything up, putting my CPC in the original shipping box with foam inserts and took it to the UPS store in late August.
I had semi-regular updates on their troubleshooting process, but they were struggling to recreate the problem. One day in September they asked for a conference call with their engineers. I agreed, walked them through how I set everything up, answered their questions, and asked some of my own. Eventually, one of their engineers decided to plug in a second hand controller (5 external AUX devices), which triggered error 16/17 and the mount slewed off failing to respond. With a way to re-create the issue, they went off to figure out how to solve it. Of the things I learned that day, two stick out in my head. First, their equipment is relatively insensitive to input voltage as it's designed to run off batteries and survive drooping voltage. Everything is behind a DC-DC converter. They also bothered to explain the CPC "whine" as an unfortunate artefact of the DC-DC converter in the mount operating at an audible frequency. Second, Celestron makes extensive use of the AUX bus internally. One example of this is the CPC mount's internal GPS receiver which is also an AUX bus device.
From there, it was more intermittent status updates until one day in mid-October. I received a phone call from Celestron. I was informed that their engineers had identified hardware changes to the CPC motor control board to resolve both an impedance mismatch on the AUX bus as well as resolve some incompatibility issues with newer AUX devices. They offered me a gift for allowing them to tinker with my scope, as well as a free cleaning and collimation. The options for the gift turned out to be somewhat unimpressive, and I chose their OIII filter. About a week later, my scope was finally on the way home.
I was excited to get my CPC back in late October, but that experience was far more disappointing than I imagined. When I saw the UPS driver almost drop the box out the back of the truck, I knew my scope had a rough ride. The box, my original shipping box, now having enough miles to need its first oil change, looked rough and its contents rattled as well. I opened it to discover the corrector's dust cover had been loose in the box and had battered the corrector. The scope was dirty internally, a far cry from the pristine example I sent in. When I connected my AUX devices and powered it on, my error 16/17 issue was fixed, but the azimuth axis had been damaged and it no longer slewed smoothly. I contacted Celestron, provided photos of the damage and video of the UPS driver almost dropping the box from a security camera. I explained that while UPS mishandled the scope in transit, they didn't make it dirtier or fail to secure the dust cover. Neither maksing tape to secure the dust cover, nor new packing materials are expensive compared to the $5100 scope and man hours to repair it. After some back and forth, Celestron offered to take the scope back for repairs on them. Not having packing materials anymore, I was instructed to leave it up to UPS on how to pack it. The UPS store was baffled that Celestron did not have a shipping crate or better instructions. I paid for shipping and packing, and thought I was waving goodby to the scope for good in early November.
About a week later, Celestron informed me they received the scope back, and that the UPS store had failed to adequately pack the scope leading to further damage. I was given no estimate on time to repair, only assurance that my scope would be restored to like new condition. From there, it was near radio silence. With the holidays approaching, I knew it was unlikely that I would be getting the scope back by the end of the year. In early January, I asked what the status of my scope was. I was considering pointing out that it was more their scope now than mine since they'd had it for longer than I had at that point, but I didn't. A few days later, I was informed that my scope was repaired and awaiting cleaning. About a week later it was on its way back to me. It arrived in a new box, with new packing material, and the corrector dust cover had been masking taped on. All of that made me smile. It's somewhat worse for wear, but they did indeed return my scope to like new condition.
In total, the experience took two weeks shy of 6 months to get fully resolved. I was impressed with Celestron's customer service and glad they stuck with me through the entire ordeal. Even more impressed they implemented some of my recommendations when my scope was shipped back. My lesson learned is that I will de-fork my CPC before either sending in the mount or OTA for service. The entire ~70lb assembly is too awkward to effectively protect for shipping without a hard shipping crate. Unfortunately, the two captive screws on my focus motor are too stripped now to allow for reinstallation and appear to be unique enough that replacement difficult. Also, my dew heater ring on the corrector wasn't correctly indexed to allow for it to be plugged in with the aluminum Celestron dew shield in place. Annoying, but not deal breaking.
For the quality of the fix for the original error 16/17 problem, I'm impressed. Not only is my original issue solved, but I no longer have occasional CPWI disconnect issues which I was assuming were a fact of life previously. For others experiencing the error 16/17 issue with a CPC and several AUX bus devices connected, there is an official fix.
