Atari TT PSU Repair
Posted: Wed May 08, 2019 8:19 am
Hi All,
I turned on my TT the other day and there was a loud bang from the machine which was the fuse blowing in the PSU. It blew up quite violently, glass shards everywhere. I took the supply out and examined it and I could see that there was some charring on the PSU connector that connects to the motherboard localised around the yellow wire, which I believe is the +12 volt supply.
I am going to try and fix the PSU and have ordered a new capacitor kit and will replace those when it arrives. I’ve also found that the diodes in the bridge rectifier at D1 and D2 are bad (continuity in both directions). I will next be checking the switching transistor and other suspects to try and bring it back to life.
I am unsure what caused the fuse to blow, but seeing as it looks like something on the 12 volt rail, I am assuming it might be the SCSI hard drive that has caused the failure. It was having difficulty spinning up on a few previous boot ups, but that’s my only reason for suspecting it.
Is anything else powered by the 12 volt rail? Do you think anything else in the machine might be dead, or would the fuse have protected the components?
If anyone has any advice about anything else I need to look out for, then I’m all ears!
Cheers
Mark
I turned on my TT the other day and there was a loud bang from the machine which was the fuse blowing in the PSU. It blew up quite violently, glass shards everywhere. I took the supply out and examined it and I could see that there was some charring on the PSU connector that connects to the motherboard localised around the yellow wire, which I believe is the +12 volt supply.
I am going to try and fix the PSU and have ordered a new capacitor kit and will replace those when it arrives. I’ve also found that the diodes in the bridge rectifier at D1 and D2 are bad (continuity in both directions). I will next be checking the switching transistor and other suspects to try and bring it back to life.
I am unsure what caused the fuse to blow, but seeing as it looks like something on the 12 volt rail, I am assuming it might be the SCSI hard drive that has caused the failure. It was having difficulty spinning up on a few previous boot ups, but that’s my only reason for suspecting it.
Is anything else powered by the 12 volt rail? Do you think anything else in the machine might be dead, or would the fuse have protected the components?
If anyone has any advice about anything else I need to look out for, then I’m all ears!
Cheers
Mark