Thread: computer not turning on, not sure if im powering it right

Originally Posted by cass944

ive got my computer completely asseblmed, i was using a 12V ac to dc converter in my house to test the computer. but i hook it up and not a hting happens. i checked with a volt meter to find that there is a good 12.43V going to the red wire and the same going to the white wire on my M1 atx.

any ideas on why nothing is happening. im sure i have the power switch wires hooked up correctly.

Yes, Voltage is not the only thing that matters when powering something, amperage is equally as important.

Tell us more about your setup please, but undoubtadly, if you are trying to power the carputers DC-DC with an AC-DC wall supply, it is too small and won't do it. I would suggest you stop also, before you have a fire.

The "wall wart" probably has a rating on it, like 12 volts, 1000 MA or something like that. That means 12 volts and 1 amp. You need about 15 amps or so to power your carputer. You will need a special DC power supply for that, something like this http://www.mfjenterprises.com/produc...rodid=MFJ-4322.

Michael

Originally Posted by cass944

ive got my computer completely asseblmed, i was using a 12V ac to dc converter in my house to test the computer. but i hook it up and not a hting happens. i checked with a volt meter to find that there is a good 12.43V going to the red wire and the same going to the white wire on my M1 atx.

any ideas on why nothing is happening. im sure i have the power switch wires hooked up correctly.

Did you connect the tiny "pc power switch cable" from the m1-atx to the mobo? No, I'm not talking about the big ATX connector, I'm talking about the one that replaces the power switch from a case.

If that's not it, you could test various pairs (not sure which ones) on the PC's side of the ATX connector to be sure the mobo is getting power.

Red wire? White wire? I'd take the blue pill..


Seriously though, can you give us a bit more to go on? Like are you testing this with everything hooked up? When you say a "good" 12v, is that measured from the black wire? I'm curious if you've got the ability to power that mobo from a standard PSU, just to test. Also, are you sure the ac/dc converter has enough current to push this whole thing? Is the M1 adequate for what mobo you're using?

Originally Posted by cass944

ive got my computer completely asseblmed, i was using a 12V ac to dc converter in my house to test the computer. but i hook it up and not a hting happens. i checked with a volt meter to find that there is a good 12.43V going to the red wire and the same going to the white wire on my M1 atx.

any ideas on why nothing is happening. im sure i have the power switch wires hooked up correctly.

Simple questio, so many possibilities.

Michael

sorry guys, i shoudl have included some more info. i think the first response answers my question. I didnt know so many amps were needed. my AC dc adapter only puts out 1200ma so im by far not getting the amps i need. I just wanted to see if i could get it going without having to go outside and hook it up to the 12v source in my car. but i guess i will just try that.

wait now i have another question. the AC DC converter i was using is the wall plug that came with my touchscreen. so if i hook my touchscreen to my 12v source in my car will there to TOO much amperage? seeing as how the lcd runs off 1200ma?

Originally Posted by cass944

wait now i have another question. the AC DC converter i was using is the wall plug that came with my touchscreen. so if i hook my touchscreen to my 12v source in my car will there to TOO much amperage? seeing as how the lcd runs off 1200ma?

No, amps and voltage are different. A device will only use as much AMPERAGE as it needs no matter how many are available, as long as it is available on the supply, you are good. VOltage on the other hand, for the most part, must be EQUAL, or you will blow the device, so don't give something that needs 5 volts 12, it will fry the device.

Michael

P.S. You could always just use a regular AC-DC Computer power supply to check that everything (except your DC-DC ps) works in the house before you go outside, and to do all your loading and stuff.

Originally Posted by cass944

wait now i have another question. the AC DC converter i was using is the wall plug that came with my touchscreen. so if i hook my touchscreen to my 12v source in my car will there to TOO much amperage? seeing as how the lcd runs off 1200ma?

Slow down. You're going to break something. You need to read a LOT more on this forum. Please read the power supply FAQ.

1) Your touch screen will only draw as many amps as it needs. You probably want to run the touch screen from DC the power supply, it's much cleaner power.

2) How many watts is your power supply? watts = volts x amps. it's about 12V, so amps = watts/12. If you have a 90W power supply it will need at LEAST 90/12 = 7.5A of input. It needs more thant that because it's not 100% efficicent. For a 90W DC-DC supply, I'd use something like a 10A DC power supply. This is NOT a simple AC-DC converter wall-brick cell-phone charger thing. It's much bigger and heavier.

I still don't see a post with specs. Please post the exact equipment you're using.

ok here are some pics.
my custom touchscreen setup for my vw gti



the thing i was hooking to my m1 atx because im an idiot



the computer