Re: Mike's Old Tat
Posted: 08 Oct 2024 21:01
A1000 Continued
After a few days in a cupboard the new caps for the PSU arrived, so I fitted them (no signs of any leakage from the originals) and it made no difference - still a black screen on almost all bootup attempts. I pulled the Agnus and Denise chips to check them (with trepidation as Paula had already lost two pins), Denise had a corroded pin which snapped off so I soldered on a replacement, contact cleaner, reseat and still black screen.
I didn't want to remove the daughterboard if I could avoid it as the connections look very fragile, but was running out of ideas so removed it and sprayed contact cleaner in the sockets. I had a look around under it and spotted something shiny under the Paula socket, which turned out to be metallic so I removed that and put it all back together. It then started booting reliably.
Not being able to leave things alone I decided to try refitting the RAM expansion. The replacement floppy drive is longer than the original so it took a lot of fiddling about to make it all fit, but it did, and a test was successful so I put the case back on only to then fail to boot reliably from floppy.
The aforementioned slightly different floppy drive seems to be interfered with by the front fascia, "lifting" the disks slightly when fully clipped in, which causes the drive to go out of alignment. I couldn't get everything to fit properly with the expansion in, so reverted it all back only to find the drive STILL getting interfered with by the fascia panel.
A lot of fiddling about to get it in the right position is in my future, which is annoying as these drives appear to be known good replacements so I am likely missing something obvious. Still, at least it powers on reliably now.
After a few days in a cupboard the new caps for the PSU arrived, so I fitted them (no signs of any leakage from the originals) and it made no difference - still a black screen on almost all bootup attempts. I pulled the Agnus and Denise chips to check them (with trepidation as Paula had already lost two pins), Denise had a corroded pin which snapped off so I soldered on a replacement, contact cleaner, reseat and still black screen.
I didn't want to remove the daughterboard if I could avoid it as the connections look very fragile, but was running out of ideas so removed it and sprayed contact cleaner in the sockets. I had a look around under it and spotted something shiny under the Paula socket, which turned out to be metallic so I removed that and put it all back together. It then started booting reliably.
Not being able to leave things alone I decided to try refitting the RAM expansion. The replacement floppy drive is longer than the original so it took a lot of fiddling about to make it all fit, but it did, and a test was successful so I put the case back on only to then fail to boot reliably from floppy.
The aforementioned slightly different floppy drive seems to be interfered with by the front fascia, "lifting" the disks slightly when fully clipped in, which causes the drive to go out of alignment. I couldn't get everything to fit properly with the expansion in, so reverted it all back only to find the drive STILL getting interfered with by the fascia panel.
A lot of fiddling about to get it in the right position is in my future, which is annoying as these drives appear to be known good replacements so I am likely missing something obvious. Still, at least it powers on reliably now.