My case of repairing NeXT magneto optical drive

Started by yusukeito, September 10, 2020, 05:23:39 AM

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yusukeito

Hello community.
I have two NeXT 5-inch 256Mbytes MO drives.
Finally. I have got working one MO drive by repairing and combining two drives.
I will share my experience here.

1st drive: Produced in 1989, builtin early NeXT Computer(68030 by default. Now upgraded to 68040)
2nd drive: Produced in 1990, builtin late NeXT Cube (non Turbo 68040 model)

Before repairing:
1st drive: Not recognize disc.
2nd drive: Causes kernel panic. Has empty q error.

First, I replaced electrolytic capacitors on digital, analog and spindle board.
Here is my parts list of the capacitors.
  • ECE-A1CKS470 (47u 16V)
  • ECE-A1CKS100 (10u 16V)
  • ECE-A1AKS220 (22u 10V)
  • UMA1H010MDD1TP (1u 50V)
  • ECE-A1HKS2R2 (2.2u 50V)
  • ECE-A1HKS3R3 (3.3u 50V)
  • UMW1V100MDD (10u 35V)
  • UMW1V220MDD (22u 35V)

The service manual is available at:  http://www.nextcomputers.org/NeXTfiles/Docs/Hardware/NeXT%20Magneto%20Optical%20Service%20Manual.pdf
And also I replaced blue tantalum capacitor(10uF) on the spindle board with 10u 16V electrolytic capacitor.
For replacing capacitors I use desoldering gun.

After recapping. I attempted testing. But with not luck on any drives.
Next, I combined some modules of the two drives.

I figured out:

  • Spindle board of 1st drive is wrong.
  • Digital Analog board of 2nd drive is wrong.
  • Laser module(bottom case) of 2nd drive is wrong.

So I removed a spindle board from 1st drive and place spindle board from 2nd drive to 1st drive.
Finally I got working 1st drive.

Working video:
https://twitter.com/novi_/status/1303726619819876352?s=20

Removed caps(left) and new caps(right):
IMG_1681.jpg

Two drives(left is 1st, right is 2nd):
IMG_1683.jpg

Rob Blessin Black Hole

Hello : A very impressive project :) Best regards Rob Blessin
Rob Blessin President computerpowwow ebay  [email protected] http://www.blackholeinc.com
303-741-9998 Serving the NeXT Community  since 2/9/93