Originally Posted by IT Diva
Yes, . . . .
There's a really good way with an add-on PCB, but there's also a quick and easy way that yields acceptable results without having to run wires and plug into a 5V molex pin somewhere.
Here's copied from the "old" A6 thread with some additional information:
For the capable DIY'er . . .
While not as optimal a solution as the active component based solutions, this is a workable solution to the issue of having a PWM D5.
I've tried it on a single and a dual D5 setup and it works satisfactorily with pullups optimized for each case, and it's dead nuts simple, though not exactly elegant.
At issue is that the D5 needs a fairly "strong" pullup, (lower resistance) . . . while the A6 works best with weaker pullups, (higher resistance).
This setup uses the 12V available from the first 2 of the 4 PWM fan pins on each channel of the A6.
The Zener diode and larger resistor form a 5V regulated source that the smaller resistor connects the PWM line to.
The diode is a 5.1V Zener diode, and the larger resistor, the 1/2 W one, is a 560 Ohm, but 470, 680, 820, or 1K will work as well. 1K may be the easiest to find.
Be sure you have the Zener diode polarity connected as in the pic.
The smaller resistor, 1/4 W, is a 2.2K which I'd suggest for a dual D5 setup, but for a single D5, a 3.3K would be fine.
The smaller size, 1/6W or 1/8W are electrically OK, but the smaller physical size makes lead breakage more of an issue, so stay with 1/4W.
Everything shown is available from RadioShack.
Hope that helps,