RAMPS 1.4 Heated Bed Wont Work, AT ALL

Hello everyone, so i ordered a RAMPS 1.4 board, Arduino mega etc to replace my MKS Gen board that broke. After setting the RAMPS board up the Heated bed wont heat up, at all The hot end and motors work fine. After doing some reading online i have measured the resistance of the bed and it's 2.8 ohms, however when powered no voltage is coming out of the heated bed terminal on the RAMPS. I've checked the polarity, marked on the bed it self and on the RAMPS board. Both are connected correctly. The fuses are not touching and feel cold, all 3 FETS also feel cold.

So why is the bed not working? Can anyone help? Thanks

Sounds to me like a bad FET. Try moving the heated bed to the FET that is working and if that works then there is something wrong with either the FET or the driver circuit.

you cant do this on a ramps

D8 is the only FET on the 11amp circuit. moving the bed to any other FET will blow the fuses

Turn out it was my mistake, like an idiot i forgot to connect the power from my PSU to the 11A terminal. Thanks for the replies anyways guys!

1) check you have 12v on D8+ pin with GND probe on either GND on the 4 pin power plug.
This should always be 12v as long as you have 12v on the 11amp plug. If its missing check the F2 (the larger of the two polyfuses)

2) If you have 12v above then either the mosfet behind D8 is dead or the control signal isn't reaching the mosfet to tun it on

This could be
1) misconfiguration of the firmware, what firmware are you running? pastebin the configuration and link it here
2) fault on your board (check continuity from the mega board D8 pin to the first pin of the mosfet, it goes threw a resistor)

You can bypass this mosfet for testing the bed (Don't try running it like this, it has no temperature control and cant' turn of the bed)
Remove the - wire from the d8 connector and connect it directly gnd on your power supply.
Turn on your power supply, while the power supply is on the bed will heat.