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Old 30 March 2020, 19:47   #21
Jake001
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I'll try playing with the micro switch and check the switches on the back.
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Old 31 March 2020, 22:00   #22
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Ok I got a better video which I'll have ready shortly but in the process I noticed that after inserting the disk the drive clicks but it's not trying to step forward it's actually stepping backwards.
Could this mean the sensor that checks if the head is at track 1 is bad/dirty??
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Old 31 March 2020, 22:32   #23
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[ Show youtube player ]
Here is the new video.
All the disks I have do the exact same thing.
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Old 31 March 2020, 23:04   #24
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Thanks for the clear video.

When there is no disk in, it will step in and out of track 0. This is what makes the familiar click sound of Amiga floppy drives.

It looks like the track motor is working, as we can see that it will seek to position track 0 when it powers up. And with a disk in it will try to read track 0, but fails three times. It probably cannot read track 0 because of one or more if it the following reasons:

- dirty disks
- dirty read head
- track misalignment
- read data disruption

What I can't see or hear in the video is whether the disk spins. The floppy drive LED comes on which is actually linked to the motor signal, but I can't see/hear the disk spins. Can you verify that it does start spinning when you put the disk in.
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Old 31 March 2020, 23:50   #25
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Yes the disk does spin.

I would think it would be either track misalignment or read data disruption as I have cleaned the heads and one of the disks which did nothing.

How would I fix that though?
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Old 04 April 2020, 08:24   #26
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To perform track alignment, or to prove that it has a problem reading disks, or writing aligned disks, I normally use Amiga Test Kit and X-Copy.

However, you obviously need to get these programs working in the first place, or test the drive on another working Amiga, or have another working drive to test with.

This is where the Gotek and/or having another working Amiga or working drive is of real benefit. Without any of that it is going to be very difficult to rule things out.
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Old 04 April 2020, 09:06   #27
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Same thing happened to me once. I cleaned a drive and thoughtlessly removed the zero track sensor. When I put it back together, it did the same as your drive. Turns out there was slight wiggle room how the track0 sensor can be placed. I loosened it a bit, moved it a millimeter up or down and tried again. Eventually I got it right enough. Worth a try before taking apart the heads...
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Old 04 April 2020, 09:17   #28
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For track alignment, you don't normally need to take apart the read/write heads.

You normally rotate the track motor itself, which will in turn rotate the worm gear and cause the read/write heads to adjust forwards or backwards depending on the rotation direction.

But yes, if the drive cannot find track 0 then this would be an issue. If you have a multimeter or logic probe then you could measure the _TRK0 signal pin - it should be LOW when it is on track 0.

Use the board layout and schematics to find where _TRK0 is.

http://www.amigapcb.org/
https://www.amigawiki.org/doku.php?i...ice:schematics
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Old 04 April 2020, 21:25   #29
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So I found an issue with the computer.
The Paula chip is only getting 1v.
And it appears that a lot of the caps are shot.
I'll be able to get replacements and replace them on Tuesday.

I'm not sure what the Paula chip does exactly so any info on that would be greatly appreciated.
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Old 04 April 2020, 21:42   #30
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Glad you've identified the issue.

Paula has several functions - sound being the most obvious. But Paula also handles the interrupts - so I'm surprised it boots to the Kickstart screen.

Paula also processes the reads from the floppy disk - hence why the floppy disk drive is not working.

If you haven't already done so, you should also check the voltage levels of the power supply.
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Old 08 April 2020, 04:08   #31
Jake001
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So the Paula chip is now getting 5 volts but I'm still having the exact same issue.
I checked to power supply as well and that works.
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Old 08 April 2020, 11:40   #32
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What did you do to fix the 5V issue?

If there was an issue with 5V then I would question everything. You need to test eliminate the socketed chips - this can only be really done by testing them in another known working Amiga.

This is when you also need a Gotek or another known working floppy drive to test and to get something like Amiga Test Kit running so that you can perform tests on the suspect drive - this is assuming this is the only issue you have and you can get another floppy drive or a Gotek to boot Amiga Test Kit.
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Old 08 April 2020, 18:38   #33
Jake001
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I replaced all of the 100uf caps across the 5v power.
I'll try adjusting the track 0 sensor next because that would be an easy fix.
Otherwise I'll check every thing I can in the computer.
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Old 12 April 2020, 20:04   #34
Jake001
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Ok so some good and bad news.

Bad news is I couldn't find the problem with the computer.
Good news is I got a fully functional A500 for around the same price from a guy nearby.
I will be returning the broken one for a full refund.
I just don't have the resources to fix it properly/efficiently.

Thank you all for the help!

- Jake
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