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Lisa Video, ProFile power issue, NiCad Leak fixes, etc.

Started by AlexTheCat123, May 27, 2021, 07:23:35 PM

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rayarachelian

#30
June 02, 2021, 09:41:11 PM
Quote from: D.Finni on June 02, 2021, 07:55:24 PM

Sure, but first you'll have to finish writing the emulator and fix all of its bugs.  :P :P

*ducks and runs*

It is open source, you can submit patches via pull reuqests. :)
You don't know what it's like, you don't have a clue, if you did you'd find yourselves doing the same thing, too, Writing the code, Writing the code

AlexTheCat123

#31
June 03, 2021, 08:43:19 AM
The EPROM finally finished programming after around 12 hours or so, but the problem with MA8 is exactly the same with the new chip. I guess it's just a matter of waiting for the 6504 to arrive from China now. The good news is that I just got a broken 5MB ProFile in the mail that I can try to fix in the meantime. The power supply is dead, so I'll try to test the rest of the electronics with an ATX power supply just to see if it works at all.

rayarachelian

#32
June 03, 2021, 09:47:51 AM
Quote from: AlexTheCat123 on June 03, 2021, 08:43:19 AM
The EPROM finally finished programming after around 12 hours or so, but the problem with MA8 is exactly the same with the new chip. I guess it's just a matter of waiting for the 6504 to arrive from China now. The good news is that I just got a broken 5MB ProFile in the mail that I can try to fix in the meantime. The power supply is dead, so I'll try to test the rest of the electronics with an ATX power supply just to see if it works at all.

Actually that might be a good hack - if you could take photos of the ATX power supply and connection to the ProFile board, etc. could make a good HOWTO/Wiki article "Replace ProFile Power Supply with ATX PS", etc.
You don't know what it's like, you don't have a clue, if you did you'd find yourselves doing the same thing, too, Writing the code, Writing the code

AlexTheCat123

#33
June 03, 2021, 12:26:45 PM
QuoteActually that might be a good hack - if you could take photos of the ATX power supply and connection to the ProFile board, etc. could make a good HOWTO/Wiki article "Replace ProFile Power Supply with ATX PS", etc.

That's a good idea! I can take some pictures once I get everything fully connected and working. I gave the controller board the 5V and 12V that it needs from one of my ATX PSUs and tried powering it up without the hard drive connected (the drive has some problems). There's processor activity and after around 20 seconds the Ready light blinks three times, then pauses, and blinks another two times. I'm assuming this is some sort of error code related to the disk not being connected, but I couldn't find any documentation anywhere to support this.

The hard drive itself seems to have trouble spinning up. I tried spinning the motor on the bottom of the drive manually to free it up and now it at least tries to spin, but it goes really slow and the TIP120 transistors that drive the motor get very hot. Thinking that maybe the grease in the motor is just dried up, I used a hair dryer to heat up the motor and after a few minutes of the hair dryer it spun up just fine, although it was a good bit slower to get up to speed than the ProFiles that I've seen on YouTube. I was goint to let it run upside down overnight to redistribute the grease inside the motor, but then I discovered that as the motor cooled off again and the effects of the hair dryer wore off, the drive would slow down and eventually stop. One of the driver transistors popped when this happened, but I fortunately have some replacement TIP120s. Now I'm scared to try again without somehow lubricating the motor in fear that another transistor will blow. Does anyone know how to solve a problem like this? Is there a way that I can lubricate the motor?

rayarachelian

#34
June 03, 2021, 08:00:33 PM
Quote from: AlexTheCat123 on June 03, 2021, 12:26:45 PM
The hard drive itself seems to have trouble spinning up. I tried spinning the motor on the bottom of the drive manually to free it up and now it at least tries to spin, but it goes really slow and the TIP120 transistors that drive the motor get very hot. Thinking that maybe the grease in the motor is just dried up, I used a hair dryer to heat up the motor and after a few minutes of the hair dryer it spun up just fine, although it was a good bit slower to get up to speed than the ProFiles that I've seen on YouTube. I was goint to let it run upside down overnight to redistribute the grease inside the motor, but then I discovered that as the motor cooled off again and the effects of the hair dryer wore off, the drive would slow down and eventually stop. One of the driver transistors popped when this happened, but I fortunately have some replacement TIP120s. Now I'm scared to try again without somehow lubricating the motor in fear that another transistor will blow. Does anyone know how to solve a problem like this? Is there a way that I can lubricate the motor?

Sadly I've not had to do this with ProFiles, just a couple of Widgets which did start spinning up properly after that. I don't know if you'd need to open it up to lubricate it or not, or you might have to open up just the motor, not sure.

* http://www.minuszerodegrees.net/manuals/Seagate/Seagate%20ST506%20-%20Service%20Manual%20-%20May82.pdf might help?
* https://stardot.org.uk/forums/viewtopic.php?t=6954
* https://www.vcfed.org/forum/forum/genres/pcs-and-clones/29157-st-225-longevity?p=361534#post361534

The ST225 one mentions using a single drop of 3-in-1 oil, maybe that would work for the ST506?
You don't know what it's like, you don't have a clue, if you did you'd find yourselves doing the same thing, too, Writing the code, Writing the code

AlexTheCat123

#35
June 04, 2021, 09:00:38 AM
I just fixed the problem and now it spins up without the transistors overheating, but the method that I used was hilariously stupid. I figured that it just needed to be spun for a while to loosen things up, so I rigged up a contraption using my dad's drill press, a hole saw, and a roll of electrical tape (don't worry, the electrical tape, not the hole saw, was the thing that actually touched the motor) that would spin the drive for me. I let it run for a few hours and the spindle motor felt a lot easier to spin afterwards. I tried powering it up and it spun up much quicker than with the hair dryer and now the transistors are running much cooler. It's really loud, so I'm going to let it run upside down for a few hours to redistribute the grease and quiet it down and then I'll reconnect the analog and controller boards and see what happens. After all of this work getting the spindle motor to spin, I sure hope that the drive is good!

AlexTheCat123

#36
June 04, 2021, 10:42:34 AM
I connected the drive to the controller board and fed everything the correct voltages from the ATX power supply, but the ready LED still does the three flashes, pause, and two more flashes thing that it did with no drive connected after it waits around 20 seconds for the drive to spin up. I'm assuming this is an error code of some sort, but I can't find any documentation on it, so what does this mean exactly?

rayarachelian

#37
June 04, 2021, 01:25:58 PM
Congrats on the motor spinner you've rigged up.

Wondering if maybe you missed a cable or if something's loose? You saw that 3 blink error before when you powered on without the drive present...
You don't know what it's like, you don't have a clue, if you did you'd find yourselves doing the same thing, too, Writing the code, Writing the code

AlexTheCat123

#38
June 04, 2021, 01:46:44 PM
QuoteWondering if maybe you missed a cable or if something's loose? You saw that 3 blink error before when you powered on without the drive present...

I've checked and reseated the cables and they all look fine, but I'm still getting those blinks. The stepper motor for the heads isn't moving at all, so maybe there's something wrong with the circuitry that drives it?

patrick

#39
June 05, 2021, 05:18:23 AM Last Edit: June 05, 2021, 05:20:37 AM by patrick
Quote from: AlexTheCat123 on June 04, 2021, 10:42:34 AM
I connected the drive to the controller board and fed everything the correct voltages from the ATX power supply, but the ready LED still does the three flashes, pause, and two more flashes thing that it did with no drive connected after it waits around 20 seconds for the drive to spin up. I'm assuming this is an error code of some sort, but I can't find any documentation on it, so what does this mean exactly?

The Ready LED just indicates the state of the /PBsy pin. The controller does not provide any fault codes.

After Reset the controller waits 18 seconds for the spindle motor to spin up and tries to read the spare table. If this works, all 0x2600 block are read one after another.


You can disconnect the controller cable and leave only the motor connected. Then move the step motor manually while the spindle is running.  This should not require much force and should not generate unusual noises. Move it back to its parking position is at the outside, far away from the track zero sensor, before stopping the spindle.

Never move the heads when the drive is not spinning at nominal speed!

AlexTheCat123

#40
June 05, 2021, 11:09:56 AM
QuoteThe Ready LED just indicates the state of the /PBsy pin. The controller does not provide any fault codes.

After looking at the ProFile schematic and the disassembly of the Z8 code yesterday, I started to realize that. I guess it's just trying and failing to read the spare table and the three flashes just happen to be the behavior of the /PBsy line in this situation.

QuoteYou can disconnect the controller cable and leave only the motor connected. Then move the step motor manually while the spindle is running.  This should not require much force and should not generate unusual noises. Move it back to its parking position is at the outside, far away from the track zero sensor, before stopping the spindle.

I tried this and it seems to move fine without any resistance or weird noises.

I decided to probe the two ULN2074B chips that drive the stepper on the controller board and discovered that, while all four inputs to the the chips have activity on them when the ready light is flashing, only one of the four outputs going to the stepper has any activity on it. After swapping the two chips around, the single good output moved with the chip, so I'm guessing that one of the ULN2074s is completely dead and the other has only that one working output. I ordered new chips from Mouser that should be here on Monday or Tuesday, so hopefully that will fix the stepper problem.

rayarachelian

#41
June 05, 2021, 11:30:22 AM
Quote from: AlexTheCat123 on June 05, 2021, 11:09:56 AM
I decided to probe the two ULN2074B chips that drive the stepper on the controller board and discovered that, while all four inputs to the the chips have activity on them when the ready light is flashing, only one of the four outputs going to the stepper has any activity on it. After swapping the two chips around, the single good output moved with the chip, so I'm guessing that one of the ULN2074s is completely dead and the other has only that one working output. I ordered new chips from Mouser that should be here on Monday or Tuesday, so hopefully that will fix the stepper problem.

Oh sorry. But I'm very glad you can still find a replacement, and glad you've found it.
You don't know what it's like, you don't have a clue, if you did you'd find yourselves doing the same thing, too, Writing the code, Writing the code

AlexTheCat123

#42
June 06, 2021, 07:53:56 AM
While waiting for those chips to come in the mail, I directed my attention to the ProFile's power supply. The fuse was blown and I'm assuming this happened because the hard drive drew too much current since it couldn't spin at all when the eBay seller turned it on to test it and they said that it powered on for a few seconds before the PSU died. I replaced it with a new one, connected the PSU to a load (a dead Macintosh SCSI hard drive since I didn't want to accidentally fry the ProFile if it didn't work), and it powered up just fine! All the voltage rails looked great, but around a minute later, one of the dreaded RIFA safety caps blew up, blew the fuse, and now the whole house smells terrible. I should have replaced those caps before even turning it on, but at least it's an easy fix. Using the original power supply will be much easier and cleaner than the horrendous setup I have right now with the ATX PSU.

rayarachelian

#43
June 06, 2021, 10:40:34 AM
Quote from: AlexTheCat123 on June 06, 2021, 07:53:56 AM
All the voltage rails looked great, but around a minute later, one of the dreaded RIFA safety caps blew up, blew the fuse, and now the whole house smells terrible. I should have replaced those caps before even turning it on, but at least it's an easy fix. Using the original power supply will be much easier and cleaner than the horrendous setup I have right now with the ATX PSU.

Ouch! Sorry.

I guess I should recap my ProFiles also. They've never been recapped, so those "RIFA The Destroyer" caps are likely due to pop. Thanks for the reminder.
You don't know what it's like, you don't have a clue, if you did you'd find yourselves doing the same thing, too, Writing the code, Writing the code

AlexTheCat123

#44
June 07, 2021, 05:17:06 PM
Great news! I got the new ULN2074s for the ProFile in the mail today and after I installed them, the head stepper came to life and started performing the surface scan! The scan seemed to finish successfully and the ready light stayed on solid like it should. I plugged it into the Lisa and the ProFile came up under the "Startup From" menu, but it gave an error 84 when I tried to boot from it. This seems to mean that the boot blocks are damaged, so I'm assuming that I can just reformat it once I get the floppy drive working and then reinstall LOS and have everything working fine, right?
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