9810 question and offer

[dramsey]

(02-26-2014 08:11 AM)Tony Duell Wrote:  The HP9810/20 card reader is a lot larger and thus a lot less fiddly to work on than the ones in the handhelds, but I find it takes me longer because I do make the new roller hub. The reason I do that is that I am worried the new O-rings could slip sideways on the original hub, there is nothing to hold them. By turning a hub with a couple of grooves in it, I know the O-rings will stay in place.

I haven't had any problem with them slipping off yet; of course, these machines don't really get used that much. I've used the same technique (different O-rings) to repair an SR-60A card reader.

(02-26-2014 08:11 AM)Tony Duell Wrote:  The only part of the printer you can't really do anything about if it fails is the printhead. Every other part can either be obtained or repaired. So don't give up on this one. Apart from the gooey platen, what other problems does it have?

I really don't know, Tony. Since the printer parts were resting in a bath of Lovecraftian Chthulu-goop, I wasn't able to perform any tests. Although I know now that the driver board works perfectly since it's in my new 9810.

(02-26-2014 08:11 AM)Tony Duell Wrote:  It is one of my favourite HP's. I think I'll put the HP9830 first, then the HP9100, then this one. It's a very interesting design.

I have all of these machines. The 9830 was the one that was closest to "perfect condition" when I obtained it, although it had a problem in that it would not reliably write tapes. This was fixed with a board-swap from a dead 9865 external drive (sorry). It has the 9866(?) thermal printer on top, which means I never need to worry about anyone stealing it.

I notice the keyboard on the 9810 is one of those wherein pressing a key simply moves a metal disk close to a printed coil on the underlying PCB, presumably registering a key stroke through some sort of inductive coupling. I imagine this makes the keyboard very reliable mechanically, and I also imagine the supporting circuitry is kinda complex.