I have a Howtek 4000 in nice shape. I tested it with Silverfast demo and scsi to USB dongle. I got it to scan 2000 DPI but not 4000 DPI. I got an error and contacted Evan at Aztek:
"F702 error can certainly be caused by a hardware related issue. In particular rotation issues, either related to spinning at the incorrect RPM or detection of the RPM. The d4000 is not capable of scanning beyond 4” x 5” at 4k, so if you are doing so with Silverfast. Either make the crop size smaller or switch it over to 2k sampling.BTW, Evan is super cool and helpful as you can see from his reply.
There really isn’t much in the way of available on site service test software as it is super old and will not run on any modern computers. Your best bet is to look at the wire harness going to and from the boards in the scanner, try cleaning the contacts of all connectors and retesting to see if you can get it to scan properly. The drum encoder which is located right behind the large front pulley can sometimes get dust or dirt in it, it isn’t easy but you might be able to carefully remove the outer cover and blow it out with compressed air. Certainly we offer new replacements, however they are expensive (around $1,800 for the old large style that the 4000 has). Try the cleaning of the encoder as a last resort."
Anyway, I found something a little more ready to do and complete. I'll leave this to someone else's todo list.
It has the scanner, 2 drums, and the SCSI-USB dongle (works with WinXP). One drum was cut for 6x12cm, just tape your film to the drum and you scan only through the film, no fluids or acetate needed. The other drum is very nice. If I remember, there is no crazing at all on either. I can try to find my test scan if you want.
Pickup in Los Angeles or possible weekend delivery up to San Francisco. I'm planning weekend trip in the next week or 2.
If you really want pictures I can take some. If you really want it shipped somewhere, I may entertain.