Hey folks,

Looking for some info on this board taken from a 15F7503 Alps drive out of a Model 70. It looks to me like someone has replaced the head stepper motor control IC and modified the circuit to match, but I'm not sure if this was a factory bodge or a custom
fix.
Anyone have one of these they can check and maybe get photos of, or know offhand?
Photo of the mess I'm looking at - https://photos.app.goo.gl/h67u8yzj8waWZM5b8

Cheers,
Nick

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

Can you remove the dust? Looking for color changes in components.

Blow the dust kittiez out of the 34 pin header leads.

Looks to have had rework in the upper right, note the green wires. There
looks to be discoloration, but they re-soldered things, so that's a firm maybe...

Huh. Maybe a good cleaning with Q-Tips and denatured/rubbing alcohol
would remove any conductive dust/grime.

On 12/13/2021 23:41, Nick Silvestro wrote:

Hey folks,

Looking for some info on this board taken from a 15F7503 Alps drive out of a Model 70. It looks to me like someone has replaced the head stepper motor control IC and modified the circuit to match, but I'm not sure if this was a factory bodge or a

custom fix.

Anyone have one of these they can check and maybe get photos of, or know offhand?
Photo of the mess I'm looking at - https://photos.app.goo.gl/h67u8yzj8waWZM5b8

Cheers,
Nick

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

I gave it a good clean and tried again, same thing - no head movement. Here's updated photos plus a close up of that rework. https://photos.app.goo.gl/1BnACbbykPYNsjS88

I also checked if the stepper was being driven at all. Both phases are constantly being given 2.3V DC, and it doesn't change when the drive begins to read at boot time, so I'm guessing this stepper driver is dead regardless. Might just try replacing it
and see. Would still love to see this board from anyone else that has this drive for comparison!

On Wednesday, December 15, 2021 at 1:07:24 AM UTC+11, Louis Ohland wrote:

Can you remove the dust? Looking for color changes in components.

Blow the dust kittiez out of the 34 pin header leads.

Looks to have had rework in the upper right, note the green wires. There looks to be discoloration, but they re-soldered things, so that's a firm maybe...

Huh. Maybe a good cleaning with Q-Tips and denatured/rubbing alcohol
would remove any conductive dust/grime.
On 12/13/2021 23:41, Nick Silvestro wrote:

Hey folks,

Looking for some info on this board taken from a 15F7503 Alps drive out of a Model 70. It looks to me like someone has replaced the head stepper motor control IC and modified the circuit to match, but I'm not sure if this was a factory bodge or a

custom fix.

Anyone have one of these they can check and maybe get photos of, or know offhand?
Photo of the mess I'm looking at - https://photos.app.goo.gl/h67u8yzj8waWZM5b8

Cheers,
Nick

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

I just realised I didn't give context to why I was looking for info here - this drive isn't reading discs and I noticed that the head stepper isn't turning at all. I've been able to manually move the screw so it's not physically restricted, which led me
to looking at the electronics side of things!

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

I'm still looking for some info on this. I found an almost identical board on ardent-tool - https://www.ardent-tool.com/8573/P70.html#ALPS_FP1T08D
However it looks like the circuitry in the bottom right of that image is slightly different than the one I have. The rest is basically identical, it just has a pin header instead of the flex pcb connector on this 15F7503.

I've scoped out a bunch of pins on the stepper driver, and it doesn't look like the input signals are actually getting there so it makes sense as to why the stepper isn't actually moving at all. I can't seem to find any info on the ALPS SC692 IC at all.

Anyone have any idea, or even the same drive that they could open up for photos and comparison?

Cheers!


On Wednesday, December 15, 2021 at 1:07:24 AM UTC+11, Louis Ohland wrote:

Can you remove the dust? Looking for color changes in components.

Blow the dust kittiez out of the 34 pin header leads.

Looks to have had rework in the upper right, note the green wires. There looks to be discoloration, but they re-soldered things, so that's a firm maybe...

Huh. Maybe a good cleaning with Q-Tips and denatured/rubbing alcohol
would remove any conductive dust/grime.
On 12/13/2021 23:41, Nick Silvestro wrote:

Hey folks,

Looking for some info on this board taken from a 15F7503 Alps drive out of a Model 70. It looks to me like someone has replaced the head stepper motor control IC and modified the circuit to match, but I'm not sure if this was a factory bodge or a

custom fix.

Anyone have one of these they can check and maybe get photos of, or know offhand?
Photo of the mess I'm looking at - https://photos.app.goo.gl/h67u8yzj8waWZM5b8

Cheers,
Nick

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)