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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: Vanfanel on July 04, 2017, 01:11:04 AM
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I decided to pull out my 1000 and hook it up for some old Amiga gaming goodness. This is the machine I grew up with. Had it since it first came out in 1985. Hooked everything up and it was working fine. Some of my game disks, not so much, but that can be remedied. I booted it up again to try a different one and now it won't load the Kickstart disk, that was indeed working just moments before. It does power on, and play the little boot up sound, but when it comes to reading the disk, it tries for about 2 seconds and does nothing. I also have no picture. If I leave the Kickstart disk out, I still have no picture, not even of the hand prompting for the Kickstart disk. Any clues as to what could be wrong?
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Well if you are comfortable with opening it up I would start with pulling the socketed chips out VERY CAREFEULY. Clean all the pins with good 99% isopropyl alcohol. I use an old toothbrush for this myself. Also, clean the sockets the same way. Let it all dry out and press the chips in and out a couple times. See if that helps.
You may also have a bad kickstart disk on top of something internally being buggered.
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Sounds like a dirty disk drive. I think that the game disks that didn't work earlier gummed up your disk drive. Your kickstart disk might be bad also. I would try cleaning the disk drive before anything else. It could be time to change the caps. I don't know about the blank screen though; I never had a 1000.
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The drive seems that it doesn't even attempt to read anymore, so perhaps there is something mechanically wrong with it. As said, could be from the old disks I tried to run through it. One thing puzzles me. Normally, if I start the 1000 without the Kickstart disk in DF0:, it will display a screen asking for the Kickstart disk. Now, it just goes to a black screen no matter what. Disassembly is no problem; I've already opened it before.
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Sometimes when you place a disk in drive that is old and degraded it will leave a residue on the drive head and make it inoperable. The only way to get the drive working again is to clean it with a proprietary disk style head cleaner. Happens to me all the time when checking old disks. The tell tail sign often is a lot of disk activity and nothing happening on the screen. Sadly the computer just hangs there no matter how many disks you put in. Get a disk head cleaner off Ebay and keep it by the computer. You should avoid using the drive till its cleaned as you could damage good disks. The trick is to keep the computer serviced and use frequently. Do not move around too much and avoid dusty environments.
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The drive seems that it doesn't even attempt to read anymore, so perhaps there is something mechanically wrong with it. As said, could be from the old disks I tried to run through it. One thing puzzles me. Normally, if I start the 1000 without the Kickstart disk in DF0:, it will display a screen asking for the Kickstart disk. Now, it just goes to a black screen no matter what. Disassembly is no problem; I've already opened it before.
Sounds like my Amiga 2000 until I replaced the motherboard. What happens when you disconnect the floppy drive (power and data cable) and try to boot? I don't know what it should do (if black screen is normal in that case), but if it asks for a disk at that point, then likely there's something electrically wrong with the floppy disk. If not, then maybe the motherboard or power supply.
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Sometimes when you place a disk in drive that is old and degraded it will leave a residue on the drive head and make it inoperable. The only way to get the drive working again is to clean it with a proprietary disk style head cleaner. Happens to me all the time when checking old disks. The tell tail sign often is a lot of disk activity and nothing happening on the screen. Sadly the computer just hangs there no matter how many disks you put in. Get a disk head cleaner off Ebay and keep it by the computer. You should avoid using the drive till its cleaned as you could damage good disks. The trick is to keep the computer serviced and use frequently. Do not move around too much and avoid dusty environments.
The thing is that there is almost no disk activity. The disk activity light is on for maybe 2 seconds and then it stops. It is not thrashing trying to read the disks. I'm well familiar with that symptom and I do have disk head cleaners here to use.
Sounds like my Amiga 2000 until I replaced the motherboard. What happens when you disconnect the floppy drive (power and data cable) and try to boot? I don't know what it should do (if black screen is normal in that case), but if it asks for a disk at that point, then likely there's something electrically wrong with the floppy disk. If not, then maybe the motherboard or power supply.
That is what I'm thinking. If I have to swap a drive, that's fine. If this machine is dead, well, I do have a whole spare 1000 I can use.
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Floppy I/O has connectivity to the CIA chips and Paula off the bat. Agnus gets involved with ChipRAM DMA, but start with the others first.
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Make sure monitor is setup to the right settings. Sounds odd but if you see no kickstart screen it may be on the wrong setting or inputs plugged in wrong. Sounds stupid, but I have 4 different monitors and I actually did this with an Amiga 2000 and found that no Display (stayed dark Grey) and after 45 minutes messing with it changed the monitor setting then bam there was Kickstart screen. After that then you can assess if drive is bad or disk is bad if that is the case
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Make sure monitor is setup to the right settings. Sounds odd but if you see no kickstart screen it may be on the wrong setting or inputs plugged in wrong. Sounds stupid, but I have 4 different monitors and I actually did this with an Amiga 2000 and found that no Display (stayed dark Grey) and after 45 minutes messing with it changed the monitor setting then bam there was Kickstart screen. After that then you can assess if drive is bad or disk is bad if that is the case
Good advice. However I had not changed any settings. One boot, it was displaying fine, a minute later, it was not. I've been lazy and haven't gotten around to diagnosing it yet.
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Floppy I/O has connectivity to the CIA chips and Paula off the bat. Agnus gets involved with ChipRAM DMA, but start with the others first.
Nope. It's Paula that gets the MFM data from the drive, and its Paula that synchronizes to the MFM data. The CIAs control the drive motor and the stepper, but receiving the data is up to Paula. The DMA channel, of course, is in Agnus. So yes, at least three chips need to be in operating condition to make disk I/O working.