Restoring an IBM AT 5170

[Maverick1978]

@Mikey99, Was that 386 upgrade from an inboard? Wanna part with it? Might be interesting to have a 2-in-1 machine, so to speak!

@Paul, I'll double-check the drive jumper settings. So far as the cabling, the cables are original IBM and are labeled with Drive letters. It's definitely on a hard drive cable.

@tezza, I've been through your site on a few different occasions, and had seen your restorations on both the IBM AT and C= SX64 (which, sadly, I haven't even had time to open mine and blow out any dust before powering on!) - great site, and informative. I'm glad that you decided to chronicle your adventures

@floppies_only, I don't have the original manuals or diskettes with my AT, unfortunately, though I'm on the lookout for them. I downloaded an image of the AT diskette from a site I found in a Google search as well as a bootable-diskette with GSETUP on it. I wrote both out, but opted for GSETUP for the GUI interface, and most especially because all of the drive types were displayed and you can cycle through them.

@modem7, I'm not hearing the spindles turn in the drive. I hear the read/write head moving during initialization and that's about it. How would one go about lubricating these? I've never had an MFM drive apart - have never even removed the logic boards. I just know that this thing gets almost too hot to touch very quickly. I expect a drive to be warm, even hot - just not too hot to touch.

 

[mikey99]

@Mikey99, Was that 386 upgrade from an inboard? Wanna part with it? Might be interesting to have a 2-in-1 machine, so to speak!

No, It was just a clone 386-25 motherboard, and unfortunately I left the batteries in the AT and it leaked electrolyte
on the MB. The 386 MB still works but the clock wont retain its setting when you power off the system. Probably
just a corroded land but haven't had time to troubleshoot that.

 

[paul]

I just know that this thing gets almost too hot to touch very quickly. I expect a drive to be warm, even hot - just not too hot to touch.

Measuring the current draw on the 5 and 12 V lines would be useful.

 

[modem7]

@modem7, I'm not hearing the spindles turn in the drive.

Okay. I enterpreted your "With that said, I'm definitely getting some noise out of the HD now, which is good." as the spindle turning, even if not properly turning.

I hear the read/write head moving during initialization and that's about it.

Odd. The drive's logic board normally won't move the heads until it knows that the spindle is up-to-speed. And the board knows that from sensors. Even the ST-412 drive in the 5160 does that.


On the assumption that the spindle isn't turning, have you heard of head stiction? It's where the heads become stuck to the platters. Quite common. Search these forums for techniques that can be used to detach the heads from the platters. Observe the warnings - too much force can result in damage.

How would one go about lubricating these? I've never had an MFM drive apart - have never even removed the logic boards.

FOR ST-4038 ONLY

WARNING: In the procedure that follows, the spindle will be revealed. If the problem you have is head stiction rather than lack of lubrication, manually forcing the spindle to rotate could rip the heads off their arms.

To prevent static damage to semiconductor devices, use anti-static procedures during the following.

1. Turn drive upside down.

2. Remove the 4 Torx screws (T-10) that secure the logic board.

3. Orientate the drive so that the front is towards you (e.g. connectors for control/data cables at rear).

4. On the right side of the logic board is a 22 pin plug/socket (like the type found on 3.5" diskette drives). Remove the plug from the socket. To facilitate that action, move the logic board to the left as far as it comfortably goes.

5. The previous step allows the right side of the board to be raised by about a centimeter. Raise the right side by that amount so that it clears the metal frame.

6. On the right side of the logic board, there is an 8-pin plug/socket. Now that the right side of the board is slightly raised, remove the plug from the socket.

[ Note: the right side of the board is now free and can be raised up to a few centimeters. ]

7. On the left side of the logic board is a 34 pin plug/socket. Remove the plug from the socket.

8. On the left side of the logic board is a 6 pin plug/socket. Remove the plug from the socket.

9. The logic board is now free. Put it in a safe place.

[ One end of the spindle is revealed. You'll see a flat copper bar that connects the center of the spindle to the drive chassis. It's purpose is to ground the spindle (well, make the spindle the same potential as the chassis). ]

10. Remove the spindle grounding bar (one Torx screw of size T-7).

11. On the end of the spindle that you can see, there are two small holes near the center. Those holes are where I would inject liberal amounts of (non-conductive) liquid lubricant. I would then tip/turn the drive through various orientations to ensure that the lubricant gets into the crevice that leads to the bearings.

12. Leave drive alone (upside down) for many hours before reassembly. That allows time for the lubricant to get where it may need to get to. Probably good to place drive on something that will catch any leaking lubricant.