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Amiga computer related discussion => Amiga Hardware Issues and discussion => Topic started by: steve30 on December 17, 2005, 11:46:48 AM
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I bought a GVP HD+ off ebay recently to use with my A500+. It doesn't work (I bought it as 'non-working') but I'm not sure what to do about it.
When I plug it in to the power supply and then to the computer, I can turn the HD on and nothing happens. The Power supply just makes a quiet humming noise, but the HD doesn't spin up, the fan doesn't come on and the LEDs don't light up.
It also makes the computer act a bit odd, regardless of weather the HD is switched on or not. It takes a long time to get to the kickstart screen, sometimes restarting it's self, and it won't boot off floppy. It just sits there trying to read the disk, however, when I remove the HD from the computer it works fine.
I think it could be the power supply that is fautly. I have tested it with my multimeter and I can't get any power out of it.
What do you think?
Might I be able to repair the Power adaptor or would I need a new one? If so, where can I get one from?
Thanks
Steve.
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Definitely sounds like a dead p/s. Why not just get the pinouts for the connector and hook both the gvp and the a500 up to a pc at or atx p/s? Then only one switch to turn the computer on. If the p/s has a monitor plug it'd power that too.
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That's a good idea. Thanks! I never thought of that.
I'll test the SCSI HD in my Mums power mac first though just to give me an idea of weather that's working. I think the SCSI connector in the PowerMac G4 is the same one as the HD inside the GVP thing.
Now I'll just have to find a suitable PSU.
What sort of power rating would be ideal?
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Or just modify the GVP so it draws power from the Amiga 500 instead. There is a guide somewhere on the net, but can't remember where....
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What do you mean?
Do you mean something like connecting the GVP to the A500 Power supply?
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The powersupply for the A500 isn't really powerful enough for that. I tried back in those days when I was using my 500 with GVP HD+. It worked but I had a lot of problems and the harddrive often didn't get up to speed so I had a lot of read and write errors.
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ATX PSU it is then.....
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Now I got the urge to go down the basement and get my old 500 and see if it still works!
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It is normal for the power supply not giving you any reading on a multimeter. The power supply has a so called sense-line, just like the A590. This basically means it won't switch on unless the A500 is on. It is a +5v line coming from the A500 switching on the power supply (that is why some of them do not have any power switches.
The switch on top of the A500HD8+, should that be the one you are refering to is not actually a on/off switch for the drive but more a disable/enable autoboot switch.
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I was wondering if it might only work when the amiga is switched on.
So if I put 5v down the 5v connector on the power supply would it turn on?
The power supply does make a sound though when it is switched on.
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No!! It has a special sense line which accepts 5v, don't use it's 5v output as an input.
To check if the power supply is the one to blame best bet would be to modify it to run off the A500's power and remove the hard disk. If it works it's the PSU, if it doesn't, well... Start looking further. You could also run the hard disk power from an AT power supply and leave the SCSI cable connected. Powering the drive from the A500 might just be asking a little too much, even for a 4.3A PS.
Here (http://members.iinet.net.au/~davem2/overclock/a500hd.html) is the site explaning how to modify your drive
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I know nothing about the PSU, but if it is the HD, then it should be fairly easy to just replace it. I personally ripped out a 850meg scsi HD from an old Macintosh and it worked perfectly fine in the gvp controller.
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It might be the HD, but when I plug it in, connect it to the computer and switch both on, it doesn't do anything. Niether the Power or HD lights come on, and the fan doesn't come on.
It does make the computer act a bit odd though, e.g. taking ages to get to kickstart screen, not booting of floppy (just reading the disk over and over again without actually doing anything), and sometimes restarting itself before getting to kickstart.
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Regarding that mod:
If I do that would it mean that the HD+ would get it's power from the amiga instead of getting it's power from the power adaptor?
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Nevermind. I got it working!
I did the mod and it didn't work. But that was because I didn't plug the HD into the computer properly.
So it was the power supply that was the problem.
I will get an ATX power supply and mod that I think some time.
Thanks for your help. :-)
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Yep, the switch on top of the HD+ box is only on/off for autoboot. Or rather, it disconnects the scsi bus entirely iirc... so if you boot up with it switched off you can't use any harddrive at all but the memory on the controller still works.
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I thought it was quite obvious that the autoboot switch was not an on/off switch. After all, it does say 'Game switch AutoBoot' which has nothing to do with On/Off.
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doctorq wrote:
Or just modify the GVP so it draws power from the Amiga 500 instead. There is a guide somewhere on the net, but can't remember where....
Here is the Mod. Self-Power A500 SCSI ControllerMod (http://members.iinet.net.au/~davem2/overclock/a500hd.html)
Works like a dream. Done it myself. :-D
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That's what I did.
I'll think I'll get an ATX power supply though as it will be good to be able to turn the HD off when I'm not using it.
It's just not right to have a fan spinning on an A500+.