After about 18 months of usage, one of my cameras stopped panning properly. Upon further investigation I found this to be due to a mechanical problem. Inside the body of the camera, there are two small stepper motors that operate the pan & tilt function. On the shaft of each is a tiny plastic gear wheel which drives a toothed belt which drives another larger gear. The larger gear rotates a shaft that has a worm drive gear on it that drives a large segment gear that rotates the camera housing. What had happened was that the tiny plastic gear on the stepper motor shaft had cracked along it's radius. At the point of the split, the gap between the teeth on either side was wider than the gaps between the teeth on the belt and the belt snagged by the broken tooth and the stepper motor shaft was just rotating inside the broken gear. If the pan direction was reversed, the camera would pan a small amount until the belt snagged on the other side of the split in the gear.
I called Panasonic about this hoping that they could send me a couple of replacement gears. They didn't seem to know much and said that there were some gears on the parts list but they didn't know which was which! They gave me another number to call (1 800 833 9626) and told me that I would have to ask to have the service manual researched for this part. I did this and they called back the next day. They said that the tiny gears were not available separately and only came with the stepper motors. They said the tilt motor was $26-50 and the pan motor was $86-50 all plus tax & shipping!
After doing some research of my own on the Internet, I found that Panasonic have a web site where you can order the parts. If you look here and enter HX-HCM10 on the right hand side and press "List Parts by Model", you will see a list of available parts. There you can see the different gears & the pan & tilt motors. According to the web site both motors were $26-50, so I decided to order them online to see what I got! They have two different part numbers for each motor and it looks like the original parts have been replaced by newer items with a 1 at the end of the part number. The ones to order are PSWQ1HCM10M1 (tilt) & PSWQ2HCM10M1 (pan). When the motors arrived just a couple of days later, it turned out that the new motors have brass gears instead of the old plastic version. Clearly Panasonic must have had quite some trouble with these!
Both of the motors are in fact the same except that the tilt motor has a longer lead than the pan motor and they have different plugs on them. This means that you can't mix up the pan & tilt functions by fitting them the wrong way round. If you are planning to do this same job yourself, remember that the main camera board is heavily integrated with CMOS chips and electrostatic discharge precautions are necessary, so make sure you have a static safe work environment! The motors are quite easy to fit although there are some small fiddly parts.
Once I had the camera all together again, I tested it out. After one pan to the left, and one to the right it appeared to be broken again! I found that the rubber toothed belt had slipped off the top of the tiny brass gear on the pan stepper motor (or off the top of the larger plastic gear). Looking more closely at the old plastic gear I found that it had a flange on the top to prevent this possibility. Even though the newer brass gear in the motor is much longer, there is nothing to stop it riding up and slipping off the larger gear which has a flange to stop the belt falling off the other side! In order to solve this problem, I put a metal washer over the shaft of the worm drive gear so that it laid flat against the larger gear where the toothed belt sits. To keep it in place I applied some hot glue with a glue gun. This prevents the belt riding up the side of the gear. With that modification the camera continued to work fine. The new tilt motor didn't appear to have this problem. Out of three camera's, this is the only one of them has failed in this way. I may just be I lucky with the others or they are new enough to have the brass gears as standard as the one that failed was the oldest. Checkout the pictures below to see the details of the repair.