exxos's Atari, Amiga & retro forum

Just curious: Where is the -12V rail?
On the Falcon PSU I have a blue wire +12V, four black wires for GND and three red wires for +5V. So... :?:

I also was quite uncertain with the low voltages on the +12V rail.
Did a recap (plus rectifier) with the exxos package. Before I had 11.4V, after recapping it drops a bit to 11.28V!

But after reading this thread everything seems to be ok. 8-)

There is never any proper regulation on the 12V rail. So the voltage is all over the place.

-12V is generated (like on the ST's) on the MB itself..


EDIT:

The lower voltage after recap is because the ripples and spikes are lower. So your meter before was reading more peak voltages and higher ripple. After recap, the peaks and ripple is less, so your meter measures less (which is a good thing) .

As exxos had noted before, these supplies need to be loaded to give a proper indication as I discovered with my Phihong supplies from the Mega STe and TT, not so much with the ST supplies I have recapped as I recall, but the Phihong will give erroneous results if not properly loaded. So I learned a new thing because of that!