ScanMate 11000 Z-test hangs, drum doesn't lift, no focus activity

[pkr1979]

Hi all – I'm working on a ScanMate 11000 drum scanner and running into a problem when attempting the Z-focus test from the service menu.

When I select Z (Find focus automatically), the scanner responds with:

Seeking aperture 3 at position 457
Done
Waiting for drum to settle, with integrator enabled.
Drum speed is ok.
StartData : 160
Filling palette 0

At this point:

• The scanner hangs indefinitely
• The drum does not move up to the scanning/focus position
• No audible focus movement happens
• The service prompt >> does not return
• I have to power-cycle the scanner to regain control

I'm using Tera Term (also tested PuTTY) via USB-serial on a Win XP machine, 9600 8N1, flow control set to none. All other service functions work.

What I suspect:
It seems the scanner expects the drum to already be in scanning position before running Z, but it doesn't move automatically. Possibly it's waiting for a signal from the PMTs or a reflection it never receives because the drum is too low.

I can move the drum using option 1 in the menu (Z/P/L), but not after Z has been triggered – it appears locked. Unfortunately, the lid can't be opened while the scanner is in service mode, so I can't insert a scan target once Z has started.

Additional context:

• Lamps do turn on when Z is triggered
• Focus calibration in ColorQuartet has previously worked fine
• No ERROR light has ever flashed
• Running a white balance calibration (via ColorQuartet) did update PMT gain values from 255/255/255 to more realistic ones for most apertures – so it seems some internal adjustments are working correctly

Questions:

1. Is this Z-hang behavior normal? Should the drum be moved manually before calling Z?
2. Could this be a firmware or software quirk in this version of the service menu?
3. Has anyone seen this behavior before – and is there a known fix or workaround?

Any insight or tips would be greatly appreciated!