In another thread, Avlin casually mentioned the Gentle Typhoon PWM mod. What PWM mod? I asked. Oh, the one where you add a PWM control wire to the fan's PCB board, where the fourth solder spot is. He was referring to the new highspeed GT's, but he claimed the mod worked on all GT's.
So I took my sole highspeed GT, an AP-30. I did this to it:
I had a bit of black wire with a fan terminal on it. I daubed it with white (after all, I didn't expect this to work). I removed the RPM reporting line from its 3-wire plug. I soldered my black-and-white wire onto the fourth solder spot. I plugged both wires into a 4-wire plug.
Lest you think I have fancy equipment, here's my soldering iron:
Yup. That's a wedge tip.
Here's the PCB:
Here's a closeup:
You can see the resin splattered everywhere.
So I plugged it into my rig. What a shock! The fan went up and down with the heatsink fans (I have three fans connected to this
, so I get to have three PWM fans running from the single PWM cpu header).
Next, I wanted to see the rpm's. So I unplugged the fan that reports its rpm's to the fan header. Then I unplugged the AP-30 from the non-rpm PWM socket, but not from Molex. It immediately went up to 4200 rpm or so. I'm lucky I didn't get bit. When I plugged the modded AP-30 into the cpu-fan socket, I got this:
WhooWEE! I now have an official PWM AP-30!!!
Back downstairs. Plug the soldering iron back in. Pull out AP-14 #6 - one of my sleeveless AP-14's. Oh boy, I'm thinking. This will be great.
Alas. I found this:
No room for a fourth wire. Ah well. You can put lots of AP-15's and under on a single Voltage-regulated fan header. I'll have to be satisfied with that.
But we now have confirmation that the PWM mod works on highspeed Gentle Typhoons. Thank you Avlin.
Edit: I got around to testing mine in detail, now that the PWM mod is in place. At 12v the fan runs at 4440 rpm (spec: 4250 rpm). With the PWM line grounded, the rate falls to 1180 rpm. Pretty cool.