I have an A1200D with a Delfina sound card and an Apollo 1260, which I have been running with the power supply that came with the Amiga. I knew the power supply is weak and could die one day. I had read that it's better to run from an A500 power supply (the light weighted version), which is more powerful.
I actually had an A500 power supply at home but it never really worked with my A1200. I couldn't understand why, because it works great with my A500. It's the light weighted version, which means it is more powerful than the power supply to the A1200. I did get some power to the A1200 with the A500 supply, but it refused to boot and I didn't get any image on the screen. Therefore, I just continued to run my A1200 from the A1200 power supply, hoping for the best.
A few days ago, I noticed that the icons on the Workbench screen got some weird garbage pixels in them. It didn't occur every time I booted my A1200 but about 50% of the time. After trying to reboot a few times, the computer could suddenly stop while booting and the screen remained black.
I suspected that the power supply might not give enough power, so I decided to take out the Delfina sound card and the turbo card to see if it helped. However, I never got that far, because after removing both the Delfina and the Apollo 1260, the computer refuses to boot.
I have disconnected everything now, even the disk drive, and I won't even get any signal to the monitor. Well, if I'm "lucky", I get something that is flickering, like if the monitor is getting a signal it cannot sync on. However, the power led is on and the hard drive is also getting power if i connect it to the mobo (but it's not booting). One thing I noticed yesterday was that if I press
, the power led goes dim and then on again. Something is apparently working.
I was first thinking that the power supply is failing. However, the A1200 power supply works great when connecting it to my A500. I tried again using the A500 power supply to my A1200, but since this didn't work before it would of course not work now either. Then I noticed that I actually have two A500 power supplies, but the fuse was broken on the other one. Just to try it out, I switched fuse between my two A500 PSU, just to see that it didn't solve my problems. I got exactly the same result.
So here I am, with a new Indivison AGA, three power supplies that evidently works well on my A500, and a nearly dead A1200 mobo.
I would be very quick declaring the mobo's death if it wasn't because it has never really worked with one of the A500 power supplies before. I don't remember now the exact behavior at the time, but I find it similar to what I see now. For all I know, the A500 power supply should be a better pick because it's more powerful, so I don't understand why it never worked with my A1200.
I wonder what the reason could be? Do I really have a dead mobo, or is it that none of my power supplies give enough stable voltage for the A1200? Still, they all work when I try them on the A500. Is the A500 less sensitive to unstable voltage?
It's an Escom mobo. I don't know if that gives some light to the story.
