I've wanted an A3000 for a while and I've finally managed to get one.
Its an early one with the cardboard box around the PSU and the motherboard has the identification 0280,0000 Iss A. Unfortunately the serial number sticker is missing so I don't know exactly what I've got. The A3000 schemaics that are available are marked 0180,0000 so I assume its not one of the very first.
I knew there was battery damage but the rest of it seemed in fairly good nick.
I've removed the battery and repaired the area around it. The zero ohm resistors were falling apart and the ROM sockets and keyboard sockets were very green so I've replaced the ROM sockets and cleaned up the keyboard ones as best I can since they are becoming unobtaineum. I have tried making my own by cut and shut on smaller connectors but not confident enough in my work to put them in yet. There were also a couple of broken traces which I've fixed.
The PSU seems fine, chucking out about 5.2V so I tried firing it up ... and ... nothing, not even a beep.
I have a Postbox so hooked it up using IanJeffray's suggested connections but no joy, I just get a succession of READ statements with just one byte read.
I assume the ROMs are RiscOS 2 as they are 28pin 831000s. Does the Postbox work with OS 2?
I'd like to upgrade to OS 3.11 but reading "RISC OS 3 software upgrade fitting instructions" it says no hardware mods are required for an A3000 but that machines with cardboard covers over the PSU
I've checked power to the major chips and they seem fine at around 4.85V except for the ROMS which came in at about 2.4! That's not going to help.
Could some of the decoupling caps be bad?
Its an early one with the cardboard box around the PSU and the motherboard has the identification 0280,0000 Iss A. Unfortunately the serial number sticker is missing so I don't know exactly what I've got. The A3000 schemaics that are available are marked 0180,0000 so I assume its not one of the very first.
I knew there was battery damage but the rest of it seemed in fairly good nick.
I've removed the battery and repaired the area around it. The zero ohm resistors were falling apart and the ROM sockets and keyboard sockets were very green so I've replaced the ROM sockets and cleaned up the keyboard ones as best I can since they are becoming unobtaineum. I have tried making my own by cut and shut on smaller connectors but not confident enough in my work to put them in yet. There were also a couple of broken traces which I've fixed.
The PSU seems fine, chucking out about 5.2V so I tried firing it up ... and ... nothing, not even a beep.
I have a Postbox so hooked it up using IanJeffray's suggested connections but no joy, I just get a succession of READ statements with just one byte read.
I assume the ROMs are RiscOS 2 as they are 28pin 831000s. Does the Postbox work with OS 2?
I'd like to upgrade to OS 3.11 but reading "RISC OS 3 software upgrade fitting instructions" it says no hardware mods are required for an A3000 but that machines with cardboard covers over the PSU
Does anyone know what this means and what else has to be done to these early machines to upgrade to OS3?"are not suitable for user upgrading. It is therefore essential that the upgrade be undertaken by a recommended Acorn Dealer or Service Agent".
I've checked power to the major chips and they seem fine at around 4.85V except for the ROMS which came in at about 2.4! That's not going to help.
Could some of the decoupling caps be bad?
Statistics: Posted by rodders — Sun Apr 06, 2025 5:54 pm