[Spindle motor problems] These motors are so-called 'electornically commutated'. Rather than having a mechncial commutator and brushgear like the mtoros you see in many books, they have (normally) 3 sets of windigns that are electronically controleld and sequenced in the right order nad at the right freqency to get the motor to turn. The position of the rotor/flywheel is detected by hall effect devies (magnetic sensors) on the PCB. If one hall-effect sensor or the drive to one set of windings is faulty, then the motor may well stop in a place where it can'r restart (in that there will be no drive to any winding when you try to start it). Of course once the motor has got going, the intertial of the flywheel keeps it going past the 'bad bit'. The motor is probsbly cvntorlled by a semi-custom IC. If you are lucky it will only be semi-cucstom, certainly in some of the floppy drives I've repaired, I've mamanged to get the motor cotnrol ICs as spare parts. Apparently they were used in VCRs for motor control too [1]. You migth try entering the numbers of an ICs near the motor widings and hall effect devices into datasheetarchive or similar to see if you can get data sheets,. If you find a 'burshless motor control IC' or simialr, it's a fair bet you've found th espindle motor driver chip. Then you can use a 'scope to see if it's getting inputs from the hall-eddect sensors and driving the coils properly. [1] Not quite the same thing, but the motor speed control ICs in my Canon CX printer have a pin labelled '33/45' in the data sheet. They were obviosuly designed for use in record player turntables... -tony

The plastic block is probsly what's called a 'slotted optoswitch' in most catalogues. Inside is an LED (sometimes vixible red, sometimes IR) and a phototransistor. Puting something opaque in the slot cuts the light off [...] It may be a stnadard problem... Perhaps the motor control IC was a bit underrated so it fails easil, or perhaps said IC was not particularly reliable anyway. Is there just one PCB in the drive, or is the spindle motor as separate board? Can you identify the spindle motor controller IC? If not, what ICs are on the board (and we'll see if we recognise anyof them)? -tony

Waht do you mean by 'platter'? Surely not the disk itseld? it's very possible that one of the PCBs, probably the upper one, is the spindle motor circuitry. If you are very lucky, it will be similar to the motors in other Sony drives of the period, and will have similar control circuitry. I think there are some photos of a 'standard' Sony drive (in bits) in by Flikr account (tonyduell). Do the parts look anythting like that? -tony

On Mon, Feb 7, 2011 at 7:21 PM, Terry Stewart <terry at webweavers.co.nz> wrote: What I'm reading from that one is... (MMI logo) MCI (c)1982 8402 Since it's made by MMI, I'm going to say it's a programmable device that Apple called an "MCI" with a copyright on the source file of 1982, manufactured the second week of 1984. That doesn't say what it _does_ but 20-pin PALs aren't unusual, not even ones from 1984. Perhaps you'll find a reference in a tech manual to the "MCI". I don't recognize the acronym in this context. -ethan

OK, I've seen those, and the others you mention in a later message.. I almsot recognise that drive. It's clearly based on the full-height single-head Sony that I know and love, and of which many exmaples have passed my bnech. The main logic board is different, and there must be other changes too, but it's similar. You should download and examine 'my' scheamtics for some of the HP 3.5" disk untis, for example the HP9121 (for the single-head drive) and the 9114A (for the double-head drive). I think some bits will be relevant The spindle motor is the upper PCB. It's clearly not the stnadard spindle motor becuaswe that has a 7 pin connector to ythe logic board nad yours has 8 pins (this is the connector along the front edge fo the logic board). I think the white wire at one end is 'extra'. I see from your later photos that you've removed the disk holder assembly. THis is one of the few things I know of that when you come to reassemble it you do not tighten the screws in a diagonal pattern 'like torquing donw the cylinder head on an engine'. It's better to do up the 2 screws on one side and then the 2 on the other. Anyway, npow that you've removed the disk holder, it's easy to get the motur out. First remvoe the little plastic senort arms that detect the disk and the write-protect hole. They're held on by E-clips, but they are aalos spring loaded, so hold them in place when removing the clip. Then lfit off the arm and the spring. The motor itslef is held down by 2 screws throguh the PCB (one looks very rusty in the photo). Takt those out nad lift the motor off the chassis. Now, there seem to be 3 ICs on the motor PCB, same as the standard one. tHe 2 SIL packages (black plastic strips with 9 pins in a row along the bottom edge) are a dual op-amp and the speed control PLL. The modifed DIL package at the front labelled TA7259 is the motor controlelr I've been mentioning. I hve checked, you can get a data sheet on that from http://www.datasheetarchive.com// I don't know how different the motro is from the standard one. My guess is that the extrra wire is for speed control (the standard motor runs at 600rpm always). It owuld be interesting to know what it connects to, and if there are any track cuts or modifications to the PCB. I notice the flexible PCB coming out of the top of th mortoe can -- that is the 'FG' (freqeucny gnnerator) coil and is used to sense the speed of the motor. The stnadard motor will run at the right speed if you jsut connect 12V to the +12V anf ground connection (get it the right way round, or you will eb replacing chips). The +5V line is only need for the sensors ad nteh motor-on control is taken to be on if it's not connected. I have no idea, alas, if the modified motor beahves i nthe same way. I also don't know how easy to convince the machin eto start the motor wit hthe drive partially dismantled (disk holder remocved). If you can. and can get the motor to run by flicking it round under these conditions, I wouild look at the mtoro coil outputs of the driver IC and the hall device inputs with a 'scope. You are looking for oen that looks 'odd'. FWIW, I've had these motors toally apart, I've replaced ICs and hall devices, I've also tapped out the bearings and replaced those. it is possible. The PQFP (swaure, flat} IC is a 4-bit microcontroller, custmm-programemd to control this drive. No, that's the data code. That's almost cvertainly a 20 pin PAL chip. No. The video amplifier is part of the read circuit (the head in this drive give a very low output signal, there's even a step-up transformer on the PCB -- that's the silver cylindrical can). The 75453 and UPa2003 are drives for the stepper motor, eject motor, and so on. Different, rather than earlier. The OA-D32V is the 'stnadard' drive running a ta constant 600 rpm and with an interface similar to a Shugart floppy drive, althpugh on a 26 pin connector with somewhat odd pinouts. The PCB is different because the Apple drive interface is different to the 'standard' one. Yes, unfortunately, you can't sense the signals directly (or at least I can't :-)). You need test gear to see what's going on. As I've said many times, the ONLY way to truely repair something is to understand how it should work and then to make measurements on the faulty one to see what it acutally is doing. And then to comapre what ouu measure whith what should be going on and thus deduce what has failed. -tony

Its been great watching the progress of this topic... I pulled out an old photo of my room from I think 1989 when I owned a Lisa (aka Mac XL) http://www.atarimuseum.com/misc/curt-room-nov_1989.jpg Curt terry stewart wrote:

I wish I'd kept it.... There was a guy, I think in Queens that (according to him) bought out all of the Lisa parts that were headed for scrap... I kinda believed it because when I went over to his house, it was just desks with Lisa's all over them, all up and running.... (Sun Remarketing???) Not sure, its been a long time. I remember buying a bunch of Parallel cards, some localtalk connectors and the Mac/XL rom upgrade (I think) and the Mac/XL OS diskette set from him. I did a lot of desktop publishing work for a small company that did "For Sale by Owner" weekly publications, did everything in Quark Express, that was a lot of fun... I miss the old Lisa... it was a great computer and I got a lot of use out of it. Curt Terry Stewart wrote:

Ok, more progress and some interesting data.. I managed to remove the clip so I could get to the pins, partly assemble the drive and plug it into the Lisa I don't have a scope at the moment. I borrow one occasionally but right now it's with its owner. What I did then was measure the voltages on the pins when the drive was showing the following symptom.... 1. (disk detect) switch is off but drive spins when on. 2. Switch is on and drive spinning 3. switch is off, (and drive will not spin on switch on) 4. Switch was on and drive not spinning What seemed to differ between 1+2 (spin) and 3+4 (no spin) was pin 6 (c-phase drive output terminal), pin 7 (b-phase drive output terminal) and pin 9 (a phase drive output terminal). Where the motor refused to turn with the switch on, these values were almost zero (with switch on or off). When the motor DID turn on switch on these were around 12v (again with switch on and off). There is more. If I measured the voltage (switch off) and slowly rotated the wheel manually values on the three pins stayed mainly at 12v. but occasionally dropped to zero for a few degrees of turn, then quickly back to 12 as I rotated. In a 360 deg rotation, there were four of these "dead" (0V) areas at right angles to each other (approx 3, 6, 9 and 12 oclock). Whenever the wheel was positioned so the voltage was zero on these pins, switching the drive on had no effect. When it was 12v, the motor sprang into life when the disk detect switch was pressed. Certainly this would seem to fit into Tony's theory. However, I'm not sure what phase drive outputs really mean in this context.? From the data above is it enough to conclude this is a damaged chip? Or could it be the motor windings themselves? I've taken voltage readings on all of the chips, but these three drive output terminal pins are the only ones that show any difference with respect to the "spins" or "doesn't spin" status. What do you think? Terry ----- Original Message ----- From: "Terry Stewart" <terry at webweavers.co.nz> To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk at classiccmp.org> Sent: Thursday, February 10, 2011 9:23 PM Subject: Re: Apple Lisa 2/10 - Progress

Ah, so it clips under the chassis too... Was there any heat-sink compound (white gunge) between them> I would assume it's soldered to the tabs, If so, you don't need to link them together, they are internallty linked inside the chip. -tony