Fan wont run with PWM control

Using a Rumba cloned main board running on 12 volts with Marlin. Installed 12V cooling fan but it will not run from the PWM pins. Runs when connected directly to 12V such as from power supply or any any spare 12v pins but will not turn on when connected to the PWM controlled pins. I measure roughly 12v on the PWM pins when speed is set to 255 and measure no voltage when speed is set to 0. So i kow both fan and board are good.

Using this fan - [www.ebay.com] .

Havent found any info about this particular problem from scouring the net. Anybody run into this problem before?

you says "when connected to the PWM controlled pins" but are you sure?

It just sounds like its digital pin, ie on or off.

Figured it out. There is a row of 3 pins and a seperate row of 2 pins. I had to connect the + wire to the + on the row of 3 pins and the - wire to - on the row of 2 pins. Makes no sense to wire the board that way so im sure something isnt right in my pins.h or something but it works anyways.