removed metal casing from psu, now how to ground it? (sits in a lego case)

Hi all,
I built my HTPC out of legos. it's pretty cool, but to fit it all in my "case", I had to remove the steel casing of the psu. I wanted a small footprint.
as you know, there is a ground wire that screws into the metal casing. well, that is gone now, so what do I ground that wire to? when I try and power on, the fan spins a split second and then nothing. I tried connecting it to the back of where the power cord connects, the ground post. no dice, same results. tried soldering it to a motherbaord screw hole. same results.

not really sure what all to do here....I want this sucker operational so I can post some oooh and aahhh pics!

Look on the bottom of the PSU's circuit board to see where the copper makes contact against the case. Usually at least one of the mounting holes will be immediately surrounded by copper, and you can attach a ground lug and nut & bolt there. But be really careful because that copper is often right next to copper that carries current, sometimes even at high voltage, and the lug or nut could short out if it turns the wrong way. For example, most PSUs have a pair of small disk capacitors soldered between that grounding copper and the 120VAC lines right next to it.

Another thing to watch for is that some PSUs have separate grounds for the AC side and the DC side and leave them unconnected to one another. This is no problem when the PSU is inside its case and in contact with a metal computer case, but otherwise you probably want the DC ground (goes to all the black power wires) to be connected to the AC ground.

better not be all multi-colored, i always hated when my lego creations turned out that way.

Any Pics? I'd like to see that PSU case.

DuckDodgers said:

Any Pics? I'd like to see that PSU case.

Click to expand...

So would I!

I just might post mine.

steve

I'd be concerned about eloctrocution myself. The PS uses house current. 110 or higher. I suspect that your case is metal...

mortimer said:

I'd be concerned about eloctrocution myself. The PS uses house current. 110 or higher. I suspect that your case is metal...

Click to expand...

I'm pretty sure his case is plastic. My LEGO case is plastic. I don't think LEGO is making any metal bricks, but it sounds like a good idea.

But, my LEGO case has 3 metal cased PSUs in it, it isn't quite a tiny HTPC, even though it does have my only TV tuner inside. (And, a ton of other stuff)

steve

pics!!

mortimer said:

I'd be concerned about eloctrocution myself. The PS uses house current. 110 or higher. I suspect that your case is metal...

Click to expand...

110 is voltage, not current.

hi guys, yeah I owe pics, but I have been finishing up my main rig. almost done....
this is project #3 out of about 8jillion.

Who in the world would have thought of making a case out of LEGOs? Didn't you ever grow up?

steve

well it worked for a second. two of the four screw holes are ringed with grounding strips. I soldered a wire to the first hole, ran it to the second, where I also soldered teh existing ground to. It booted up,sat in bios, and when I came back, it was powered off. there was also a dull squeal from the psu. unpluggin and replugging, the light goes back on, but as soon as I hit the power button, half a spin of fan, and nothing, then the squeal. sometimes when I plug in the cord, it squals immediately.

HELP! so close, yet so far.

Is there any way you could a PSU with the case on it? I've always had my PSUs just as a standard PSU. Didn't pull it apart.

If you need to, stick it halfway out the back, and build a wall around it with LEGOs. I have found that a normal PSU is just the right size,to fit through a hole in a LEGO wall

Double sided sponge tape is your friend!

Post some pictures.

Also, try with a cased PSU, to make sure the PSU is still alive.

steve

Have you tried screwing it to where the PCB screwed to the case? I am looking at a dead PS right now and there is solder around the hole for grounding, that would be equivilent to screwing it to the case.

with all the messing around with it that you have been doing, have you put the PSU back together yet to make sure it still actually works?