A590 harddisk distortion

[Speelgoedmannetje]

Hello all,
The display of my Amiga 500 had some distortion in it. As things worsened over time, I thought it was something nearby that was distorting it. But I found out now that the harddrive is to blame, and I think it's primarily the psu that is to blame, because the harddrive itself runs perfectly, no errors/slowdowns whatsoever. Has any one has any experience with this?

[Speelgoedmannetje]

What exactly is the "distortion?" Is this seen on a CRT (electromagnetic) or a TFT/LCD/LED?  Does it improve the further you move the PSU away?  Have you checked the voltages of your PSU?

"So many questions, so little time."

I've moved the psu far away from the good ol' 1084S monitor but the picture did not improve at all. The distortion shows dark and bright horizontal stripes in the picture.
I'll still have to check the voltages.

[Speelgoedmannetje]

Not sure what you mean by "distortion", but here's a couple suggestions for you if you suspect the A590 PSU is causing you trouble:

1 - Convert your A590 to use motherboard power:
http://members.iinet.net.au/~davem2/overclock/a500hd.html

However if you're going to do this I'd recommend getting one of those MechWare SCSI card readers or a SCSI-to-IDE bridge plus an IDE-to-CF adapter, so you you can use low-power CF cards.

Hm, that sounds like a nice idea..

2 - Get this adapter from AmigaKit and an old PC PSU:
http://amigakit.leamancomputing.com/catalog/product_info.php?cPath=39&products_id=901

Well, I looked into that but I don't think that's really suitable for the A590. The A590 psu has a 'power sense' line and this one does not. It would mean the A590 is continuously switched on instead of being switched on/off by the Amiga. I wonder if I can make an ATX psu react to that 'power sense' line.

[Speelgoedmannetje]

Is the video distortion there when you remove the A590 from the system (A500 alone)?

The distortion is gone completely if I remove the A590. Even if I have the psu turned on near the monitor.

Have you added some kind of acceleration to the A500/A590 setup?

Well, I got the standard Commodore A501 memory upgrade (of which I recently replaced the battery)

[Speelgoedmannetje]

Still not really clear what you mean by "distortion"

Eh, noise in the picture (not in sound though, as far as I can hear it).

but if you have your entire system hooked up to a power strip you can just turn it all on or off that way - no need to fuss with the "power sense" line.  

Aw well, I just want it to be working neat again.
It's my precious, you know?

[Speelgoedmannetje]

distortion could be caused by several things.
RFI -http://en.wikipedia.org/wiki/Radio-frequency_interference
and using Ferrite_bead is used to suppress it. - http://en.wikipedia.org/wiki/Ferrite_bead
but by moving the pwr supply away not helping it is more an indication of a ground loop.
http://en.wikipedia.org/wiki/Ground_loop_%28electricity%29
Plugging computer, hard drive and monitor to the same outlet should cure it if that is what is causing the problem.

Yes a ground loop is what it looks like, but it has not always been there, it gradually occurred, sometimes, sometimes not, sometimes faint, but eventually continuously. Maybe some thing that made it short circuit?

Btw. I've had some difficulty connecting the A590 a while ago. It did spin up and then it began to spin fast, and locked up the Amiga (black screen, no guru), I had to clean the edge connector and seat it really well to make it work again.