TT PSU problems

Repairs & upgrades.
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Steve
Posts: 58
Joined: Fri Sep 15, 2017 11:49 am

TT PSU problems

Post by Steve » Sat Apr 14, 2018 3:24 pm

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

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exxos
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Re: TT PSU problems

Post by exxos » Sat Apr 14, 2018 5:25 pm

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..
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Steve
Posts: 58
Joined: Fri Sep 15, 2017 11:49 am

Re: TT PSU problems

Post by Steve » Sun Apr 15, 2018 4:55 am

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: 58
Joined: Fri Sep 15, 2017 11:49 am

Re: TT PSU problems

Post by Steve » Sun Apr 15, 2018 10:00 am

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

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