Recently I identified and solved two problems with SD-320 and SD-321 disk drives as used in the Epson QX-10 and TF-20 (and probably TF-15). Both are caused by dried out grease, and require disassembly and re-assembly of large part of the drive. One it the problem the diskette will not insert completely. About one cm the disk is stopped. Sometimes using extra force will help. As side effect the diskette isn't actively pushed out on eject. The other one is the diskette is not ejected when the PUSH button is pressed. The lock mechanism is not released and remains visible, locking the diskette. With some force the lock can be forced down (QX-10) or left (TF-20) freeing the diskette. Issue one is caused by dried out grease on the 'ejector' that is pushed back when a diskette is inserted and produces the force to eject it later. As a side effect, it enables the Push button. The ejector slides over the bottom of the drive chassis and is kept in place by two fixed bolts. It is the grease around those bolts that create the problem. Issue 2 is caused by sticky grease in a mechanism that frees the diskette lock. This mechanism, coupled to the PUSH button double action mechanism, unlocks the ejector by tipping the safety lever when the PUSH button moves out. In my case, exercising the mechanism a bit made it work again. It is quite complicated, and I stopped trying to grok it soon after it started to work again. The Epson QX-10 Technical Manual part 1 contains a description of the mechanism, part 2 the disassembly/assembly instructions for the SD-321. The SD-320 also has a Head Load selenoid, but the same procedures can be used. fjk, 2013-05-11