FC-6

[Seeing Red]

Well I don't seem to have too much luck with these. I sent back two because of display issues. They were using the same display as the FC-5V1s.

Now I got this current one from a different vendor and found out a different problem. I've noticed this after seeing my AP15s don't run at the rated RPMs. I kind of ignored it since 1630 RPM is pretty close to the 10% tolerance.

The other day I plugged the fans into a molex connector and had the RPM sensor plugged into the controller. Now I notice the fans are running at 1750 RPM. This is because the highest voltage it outputs is 11V. I've checked this with a voltmeter on all four channels.

I've been too busy with work and putting my rig back together to deal with this so it's past the 30-Day warranty provided by the vendor. I know I can't return it to Lamptron for repair because their production facilities are in China and it would cost more to ship it than buy another one.

I guess I'm asking how I can fix this. I'm a recently graduated electrical engineer so if I could get a circuit diagram or the part numbers for the MOSFETs that would be great. I'm mapping out the traces, but this is taking forever.

[miahallen]

FB voltmod? Should be easy for you

[Spawne32]

Gonna look into it for you and get back to you to see what we can do.

[Seeing Red]

FB voltmod? Should be easy for you

In this case an FB voltmod wouldn't work since this controller doesn't use PWM control like the FC-2.

After looking at the PCB a little more I actually found that the circuit is a pretty simple form of power regulation. It just uses a potentiometer to regulate voltage across the gate of the MOSFET.

Using the voltmeter I could see the MOSFET is only outputting 11V after being fed a 12V signal to the gate. The way it's wired has me believe that this a p-channel transistor. After brushing up on my knowledge of MOSFET characteristics I now know that the Rds(on) value must be pretty large to account for a 1V drop across the transistor even on light loads of a couple Watts. I guess someone cheaped out somewhere and bought up some crappy MOSFETs. That's probably why all the faces of them were sanded off so no one could get a part number...

I can possibly find another transistor with some good characteristics and be able to pull more power through the unit. I don't think I have to beef anything else up to run this unit at a higher amperage.

Of course I'll hold off on any modifications until Spawne32 replies back.

[Spawne32]

I cant guarantee that the engineers are gona give the technical info I need to answer your question because the PCB is proprietary and they keep this stuff pretty secretive, but I will do my best, we may just replace the unit even with it being outside of warranty.

[Seeing Red]

Thanks for trying for me Spawne32. I can provide proof of malfunction if needed.

Too bad they just can't give me the part number of the MOSFETs on a FC-5. They grinded all the faces off those too.

[Spawne32]

Thanks for trying for me Spawne32. I can provide proof of malfunction if needed.

Too bad they just can't give me the part number of the MOSFETs on a FC-5. They grinded all the faces off those too.

they do that for infringement purposes

[Seeing Red]

Any news on this?

[Spawne32]

I did receive a response about this, it seems that the technical layout of the pcb is classified information. Im sorry that I cant help you further with this, im still pushing for a replacement however.