I have a few of these HD drives out of SEs, Classics, LCs... and they all seem to be perfect in terms of logic.
I've attached some scans I did on a good working MFD 75W 01G and that may be useful to other people trying to pin point issues with this drive.
From what I can see all my non working drives send the correct signals to the heads, main motor spins speed seems to be correct as the step motor is triggered at the correct frequency.
That all leads to conclude the logic circuitry is working perfectly and the issue is head alignment or something to do with heads.
Then tried to manually re-align the track 0 sensor in 0.05mm intervals (using a micrometer) and no success.
So I am wondering, if there ever been an alignment floppy and software for these drives?
Scan 1 Copy 4.pdf
Scan 1 Copy 5.pdf
At work we use 3M 8810 for chips with bare dies like that. It will probably hold, but won't be great, even if you use strong thermal adhesive. Those screw type heatsinks aren't very common nowadays so you might be out of luck re-using the original parts.
In combination with the thermal tape, I'd recommend getting a more modern heatsink with integrated clip, something like this (or check enzotech, as an alternate vendor): https://www.radianheatsinks.com/ez-snap-clip/
Hmm yes, I guess they are very rarely gold-plated. Either way, I don't think the layer of flux would be good for connectivity. We will look into what can be done about this, but as far as we can tell, good contact is being made.
No, this is a separate issue, and yeah, the patch will be required for System 7.5 unless someone can tell me what the specific issue, and then maybe I can patch a fix into the IIsi base ROM.
Here's a question: is there an approved method of detecting what hard discs are attached to the Lisa, or at least a method that is known to work? If worst comes to worst I will have a look at the boot ROM source, but it slightly scares me.
And it does look tempting, but 91 pieces and some really small SMD...
I'm not there yet... ;-( (Even tho that little voice inside my head is telling me to go for it.. But he's the same voice that told me there was no way VHS would win and I should buy Beta, so I don't generally listen to him anymore..)