Minolta DiMAGE Scan Elite II

[ttyr2]

I bought a used Minolta AF-2920 off of ebay in untested condition for use with my beige G3/MacOS 9.2.2. I knew it was a gamble.

When I received it, there was no sign of power other than a very brief motor noise when power was supplied and the power button turned on. Being as how there was no returns and no guarantees, I opened it up and found one of two thin ribbon cables disconnected. Once I plugged that back in, the status light on the front started working.

Currently the power LED blinks about once a second and each time it is turned on the scanner carriage servo inside turns a couple of degrees and then stops. After that, it doesn't do anything and never completes initialization. Likewise the scanner software doesn't detect the scanner.

I looked over all the capacitors with a good light and magnifying glasses and didn't find any that were obviously leaking or corroded.

Some of the documentation talks about a locking screw or pin that locks the scanner mechanism but I couldn't find it, and I'm able to gently turn the servo and move the mechanism with the power off with no binding.

Not having a schematic, I checked a couple of spots that were marked VCC and saw 5VDC to ground. That's as far as I got probing around.

What do you guys think?

 

[ttyr2]

Did some more diagnostic work today. What I think is the mirror scanner carriage underneath appears to move ok. If I pull the stepper motor (it has a worm gear that locks the carriage), move the carriage a bit, put the stepper back in and power it up, the carriage moves until it trips the flag sensor, so I think that part is good. Back on top of the unit, I was looking at the scanner strip transport assembly. That motor moves a couple degrees on power up and then stops. Even if I crank that mechanism a ways so the flag sensor (separate from the sensor on the bottom) is not obstructed and power it up, the carriage doesn't reset. I noticed the small circuit board that is soldered to the sensor was tweaked a lot, like bent probably 10deg or so from square with the sensor. I straightened it and did a basic LED test on the emitter and it appears good (infinite resistance one direction, .987v the other direction). I read online that my cell phone should see the LED light as purple when the sensor is powered up. I'm going to try powering the sensor back up and so a voltage reading on the phototransistor when I move something in and out of the slot.

There are no markings on the sensor so I'm not sure how to source a replacement. I thought about gambling on buying another dead/parts scanner just to rob the sensor out of it.

 

[ttyr2]

On further reflecting, and tinkering, the upper carriage does move and resets, so I think the flag sensor on that part is ok.

When I launch VueScan, it tells me to close the door on the scanner. I click ok, then hear the scanner reset (or move the carriage), and then it stops, blinks 5 times rapidly in a pattern, and VueScan locks up. I've emailed the log file to VueScan for assistance.

 

[ttyr2]

Skip forward a couple of days. While it was working at first, the stepper motor that drives the scanning carriage is now NOT turning the screw that moves the carriage. It turns out the plastic coupler is cracked on the end and the allen screws are not able to grab the motor shaft.

I think that drive was working originally, I went off on other tangents fixing things, and when the scanner started to actually scan a negative, that coupler finally broke loose. I just assumed that the scanner mechanism was moving and failed to notice that it had stopped moving. For now, I'm going to try heat-embedding a small metal wire ring in the end of the coupler to reinforce the area. I think it will be strong enough to do the job. It's made out of acetal or nylon, neither of which are easy to glue, so a mechanical solution is best. I haven't been able to find a plastic replacement for that part, only metal.