ive installed a new mobo ATX but can't get it to run at all I don't know if ive installed the front panel plugs correctly It calles for PWR/SLP plug on the header which i don't have, didn't need with the old mobo.
Not enough information. Please post motherboard info, power supply info.
As for the power connectors on the motherboard read the manual it will tell you how to plug it in.
These days mobos have two power connectors:
1. ATX, which can be 20 or 24 pins (if I remember correctly) If you have a 24 pin connector on the mobo but only 20 pins on the supply you can still use it you just have to leave four pins empty.
2. Core voltage which can be four pins or eight pins and is also backward compatible. That means you can plug the four pin cable into the eight pin motherboard connector, just have to get the key shapes lined up correctly.
As for the front panel plugs, I'm assuming you mean the power button / hd led / power led and reset button connector.
Generally the power button is two pins and can be wired either way. Same with the reset switch. With the LED headers generally they are two pins and you have to put them on the right way (white or black wire is usually ground and colored wire is positive voltage).
But you don't have to have the switch connected to turn on the mobo. Assuming you have both power connectors installed correctly (you need them both, bad things might happen if you don't), then all you have to do is use a #2 pencil to short between the pins that are labelled "power switch". You can use other things but you have to be careful to only short those two pins. Its been a long time since I've used a #2 pencil, I guess there's a chance it won't work.
This is just guesswork. Give me more info and I'll have more specific suggestions.
