TT PSU problems

Repairs & upgrades.
Post Reply
Steve
Posts: 2729
Joined: Fri Sep 15, 2017 11:49 am

TT PSU problems

Post by Steve »

Hi,

My TT PSU seems to be outputting 7.5v from the red wire, and 0v from the yellow on the molex connector. This is whether the PSU is connected to the machine or not. I also measured 7.5v on some components on the motherboard. I think this must be a problem, as my machine isn't working.

Any advice on fixing it? It has already been re-capped and worked for many months before this happened.
Or can I buy something modern to replace it?

Thx

Steve
User avatar
exxos
Site Admin
Site Admin
Posts: 24182
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: TT PSU problems

Post by exxos »

PSU of course needs to be tested under load of resistors. But I fear if its outputted 7.5V onto your machine then it could have killed it :(

I would check with scope and make sure you are not seeing peak voltages with your meter. May be bad soldering on output capacitors..
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Steve
Posts: 2729
Joined: Fri Sep 15, 2017 11:49 am

Re: TT PSU problems

Post by Steve »

Oh the machine boots in some situations. It only boots if I press the reset button, and it will only boot if the fast RAM isn't installed. Otherwise it just locks up on the atari logo.
Maybe ill post some high res pics of the PSU. By the way I only have a multimeter for testing.
Steve
Posts: 2729
Joined: Fri Sep 15, 2017 11:49 am

Re: TT PSU problems

Post by Steve »

I'm gonna send my motherboard and psu to germany for testing :)
Post Reply

Return to “PSU (power supplies)”