Tempest Transformer Bad?

rcranetx

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Testing tempest power supply at the main connector gives me higher than normal voltages across the board. 36 is 56, 10.3 is 18 etc. I've replaced the bridge and tested with another big blue. Just can't get voltages right. Lowest I can get 5V via the pot is 6.5V which is no good for the main board.

Have you had a tempest transformer go bad? I always ready read that if a transformer went bad, you'd definitely know it.
 
It's normal for the 10.3 volt source to be higher, especially unloaded. That said, I normally see it around 14 or so. Are you sure that your AR-II board is good?

Also, what is the voltage you get at the wall? Higher input voltage gives higher output voltage.

-Ian
 
Ian,
Thanks for the quick reply. Forgot to mention that I also replaced most caps and the VRs on the ARII as well. I can try a different power source.
 
Also try cleaning the edge connector pins. Sometimes they need to be replaced if the +5 or return line are to corroded.
 
Some power bricks have a multiple connector. This setup allows you to connect to different currents. 220 and 110. It this option is present on your brick, the one you want is the yellow connector for standard U.S. current 110volts.
 

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Yep, its there. The other day the machine was shook and went dead (was working 100%). Upon closer examination, 20V 32A fuse was blown. Every since I replaced it, its been this behavior.
 
Unplug everything and lift the brick up off the floor of the cabinet, make sure you have no loose connections. Or wires touching. Try not to short out big blue.
 
Alright, I'm a total dumb ass. Something so simple I am obligated to beg for your forgiveness. Too repay for this transgression, I'm going to ship one can of deoxit to whoever can guess what was wrong.
 
The common stuff stuff I've found wrong on the Atari power brick:
Most common 1) a Bad bridge capacitor 2) Bad big blue 3) Bad connectors on the bridge capacitor
 
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All new fuses. Remember, all my voltage readings were high...
 
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