Miniscribe 8425 doesn't turn on

[musicforlife]

I have got this card within another 5150 PC but it doesn't power up, or to be more exact, doesn't start to spin. When powering up, there's no sounds coming out and there's only the red led blinking constantly in specific pattern loop (rapid blinks, rapid blinks, longer blink). Is there anything I could fix it? I also tested different power sources and computers.

 

[modem7]

... and there's only the red led blinking constantly in specific pattern loop (rapid blinks, rapid blinks, longer blink).

That sounds like one of the error codes that some Miniscribe hard drives display.

At [here] is a manual for the Miniscribe 8425. Chapter 10 of that manual (within, search for "10.2MESSAGE READOUT") describes how to translate the LED flashes to an error code, and lists a crude meaning for each error code.

I suspect that the error code you see, will be between 0 and 4 (inclusive). For example, maybe if there is a RAM error, the drive displays error 0 in a loop, never going further to the point of commanding a start of the spindle motor.

Is there anything I could fix it?

Using the pointed-to information, what is the error code ?

 

[Fastopen]

If you can upload a video with the LED blinking code we can help you, as modem7 says. Attending to your written blinking may be:
Code 2 - Interface chip diagnostic failure
Code 3 - Write Fault latch will not reset

The first thing I always do is to dissasemble PCB and try to help spinning motor to rotate, because if your drive was stopped several years, motor can be stucked. (this is not te best option, but I recover many miniscribe's with this). The last one I've repaired has the same sympthoms like yours, but in this case there is a resistor near 6 pin spindle motor conector that was completely broken. I've changed it and drive return to life.

Regards,

 

[dmuntz]

I'm going to hijack this old thread for a related issue. 8425 is telling me 1101, which is "Seek error during bum-in or recal." The drive makes mostly "correct" noises. I can see the stepper stepping, and watch it seek back and forth a couple times before it throws this error and gives up. So, having watched it do a good imitation of successfully seeking, any thoughts why the drive might be reporting failure? I'd expect a different error if it were unable to find track 0, but maybe there's something else it looks for on the media to determine whether a seek worked? BIOS reports 1701 (obviously), and the drive doesn't appear available to the low-level format program (debug g=c800:5). Oh, also of note, this drive has something I hadn't seen before, which is the stepper motor has an 'arm' attached to it that moves between what appears to be a sensor of some sort. Sensor is labeled "KT2625" "4063303" "8641" (last one probably date code). Looks like it has wiring for an emitter/detector pair, but can't get a good enough look at it to tell if it's optical. Maybe the drive is just blind...

 

[modem7]

Oh, also of note, this drive has something I hadn't seen before, which is the stepper motor has an 'arm' attached to it that moves between what appears to be a sensor of some sort. Sensor is labeled "KT2625" "4063303" "8641" (last one probably date code). Looks like it has wiring for an emitter/detector pair, but can't get a good enough look at it to tell if it's optical.

Seagate ST-412 example, and describing text, at [here].

BIOS reports 1701 (obviously), ...

Yes, the drive won't be signaling to the controller that it is 'ready'.

I'd expect a different error if it were unable to find track 0, but maybe there's something else it looks for on the media to determine whether a seek worked?

If the 8425 used a servo positioning mechanism, maybe, but according to [here], it uses a stepper motor.

Considering a stepper motor, other positioning logic could be used in the self-test.
For example, imagine failure of test 6 in the following fictional example:

Test 5 - Cylinder 0 (track 0) switch

Step 1: If cylinder 0 switch not activated, step out until the cylinder 0 switch activates. If not activated after [drive's cylinder count] steps, trigger 'track 0 switch' error.
Step 2: Step in 1 time (i.e. heads expected to then be over cylinder 1)
Step 3: Verify that the cylinder 0 switch is no longer activated. If not as expected, trigger 'track 0 switch' error.
Step 4: Step out 1 time (i.e. heads expected to then be over cylinder 0)
Step 5: Verify that the cylinder 0 switch is activated. If not as expected, trigger 'track 0 switch' error.

Test 6 - Long stepping test (now that we have very good confidence in the cylinder 0 switch)

Step 1: Step in 20 times (i.e. heads expected to then be over cylinder 20)
Step 2: Step out 5 times (i.e. heads expected to then be over cylinder 15)
Step 3: Step in 100 times (i.e. heads expected to then be over cylinder 115)
Step 4: Step out 115 times (i.e. heads expected to then be over cylinder 0)
Step 5: If cylinder 0 switch not activated, trigger 'seeking' error.