Psu Fix Tutorial, You wanted it... You got it Options

[Arjun]

Damn, you beat me too it . I ordered a broken PSU just to do this haha. Good job though!

[liqwidsky]

There's a couple little tricks you can do if you're having trouble. Take your #1 philips and look down on below the edge of the black plastic housing. You'll see a screw that looks just below the edge. There will be screws there. If you have the smaller plate on the left (I'm sorry this is so vague... I'm at work right now.) then on that smaller plate there's two screws. The one on the right is the one you want to unscrew. This will allow the psu to come away from the heat plate. The heat plate is what's stuck and is very easy to extract once you have the pcb out of the way since you don't have to be careful anymore. Also, something I didn't put in my tutorial: Under the big heat plate there is a thermal diode. It is what causes the 3 red quadrants and your psu led to turn red. If you are sure your psu is going to be properly cooled you can unattach that from the heatplate. It will NEVER read a reading of too high floating in air. The downside is, if your psu isn't properly ventilated it will cook and possibly cause fire so this is strongly discouraged. The fuse is right next to the AC power in. It can easily be replaced.

Edit: The stuff that is holding it is like a yellow plastic substance with some kind of porous adhesive. It can't be a very good conductor and if I remember correctly it is seperating the heat duct from the actual psu. simply getting that out of there is an improvement imho.

Thanks. That was really vague but I figured it out; turns out there was a screw holding it in that connects to a bracket screwed into the heatsink. I was leaving it in so I wouldn't put stress on the joint soldered into the pcb but that sucker has to come out. I'll post some detailed pics later of the entire psu. The fan is a Delta model # BFB0412HA if someone wants to research it and see if a replacement with higher cfm is available.

[Mick Garvey]

OMG you dont know how bad I want to see those pics!

[BCfosheezy]

Thanks. That was really vague but I figured it out; turns out there was a screw holding it in that connects to a bracket screwed into the heatsink. I was leaving it in so I wouldn't put stress on the joint soldered into the pcb but that sucker has to come out. I'll post some detailed pics later of the entire psu. The fan is a Delta model # BFB0412HA if someone wants to research it and see if a replacement with higher cfm is available.

lol that's what I said to do

[liqwidsky]

Did you re-assemble your psu without the yellow plastic material? It looks like it's necessary for electrical isolation of that section but there has to be a better non-conducting heat transfer material than that. Oh and that is one huge fucking capacitor in there... 220v/820 microfarads, enough to completely fuck your day up.

[BCfosheezy]

Did you re-assemble your psu without the yellow plastic material? It looks like it's necessary for electrical isolation of that section but there has to be a better non-conducting heat transfer material than that. Oh and that is one huge fucking capacitor in there... 220v/820 microfarads, enough to completely fuck your day up.

Yeah that capacitor could easily be used as a defibulator. Anyways no I didn't put any of that insulation back. I saw no need for it. There was nothing that needed electrical insulation.

[liqwidsky]

Yeah that capacitor could easily be used as a defibulator. Anyways no I didn't put any of that insulation back. I saw no need for it. There was nothing that needed electrical insulation.

Are you sure? I don't think the manufacturer would put that insulation in if there wasn't a reason for it. I'm very nervous about connecting those two sections even though they both seem to be ground, according to my multimeter there is no direct connection between them. But you did it and there wasn't any problem?

Edit: I just measured the voltage when power is connected: In standby I'm getting 67v AC across those two sections, when the xbox is on it's at 51v AC.

Be careful man.

This post has been edited by liqwidsky: Dec 21 2005, 05:26 AM

[BCfosheezy]

Are you sure? I don't think the manufacturer would put that insulation in if there wasn't a reason for it. I'm very nervous about connecting those two sections even though they both seem to be ground, according to my multimeter there is no direct connection between them. But you did it and there wasn't any problem?

Edit: I just measured the voltage when power is connected: In standby I'm getting 67v AC across those two sections, when the xbox is on it's at 51v AC.

Be careful man.

They are seperated by an insulator known as air. My AS5 is touching both to the heat duct. Probably if AS5 didn't have as much electrical resistance it would cause a short. I'll come up with a better way to do this. Yeah they put that pad there to prevent shorts... but it also insulates heat. Safety first but I'm still going to find a way to safely cool this thing.

[liqwidsky]

They are seperated by an insulator known as air. My AS5 is touching both to the heat duct. Probably if AS5 didn't have as much electrical resistance it would cause a short. I'll come up with a better way to do this. Yeah they put that pad there to prevent shorts... but it also insulates heat. Safety first but I'm still going to find a way to safely cool this thing.

Remember AS5 is non-conductive but it is slightly capacitive, not a pure electrical insulator.

Right now I'm looking for some inexpensive non-conducting thermal tape that would conduct heat better than the yellow plastic garbage but still act as a reliable insulator.

[liqwidsky]

After doing some research the thermal tape turns out to be a bad idea for this application. Now I'm leaning toward using a thermal adhesive like this one to bond the plate that's screwed in (the one with the thermistor attached to it) to the sink it's screwed into, making sure there is no electrical contact by clamping in a multimeter during the gluing process and possibly using some very tiny spacers. Of course the screws will be tossed since putting them back in would ruin the electrical isolation and the plate would now be "permanently" glued on. Then it would be safe to use AS5 on the top of the plate.

Oh and I got a nice little 51v shock while I was being careless comparing the heat output of those two sinks... I touched them both at the same time with 2 different hands, current went straight through my heart. Good times...

I also did a little experimenting with the potentiometer next to the fan leads, it's variable from 10 ohms - 4.3k ohms (original setting was ~2k ohms) but fan voltage stayed a fairly steady 4.5v no matter what value the pot was on.

This post has been edited by liqwidsky: Dec 21 2005, 10:28 PM

[liqwidsky]

Good news. After I posted that the fan runs at 4.5v, I looked at the bottom of it and noticed it's actually a 12v fan. So I hooked it up to a 12v power source (spare pc powersupply) and it blows a shitload more air, but of course the noise output is much higher. Not sure what it will sound like with the psu re-assembled but the only problem now is finding a 12v lead to hook it up to and I'm not sure what will happen if I disconnect the 4.5v lead connected to it now.

Edit: Found the 12v lead.

This post has been edited by liqwidsky: Dec 21 2005, 11:32 PM

[leorimolo]

pixs

[TheSandman87]

could SOMEONE please get a camera....tho i love the play by play walk-thu

[SuDDeN]

"shakes head in disbelief"
"begins to sob uncontrolably"

Why must you make us sufer with all of this talk about the internals of the PSU "Power Brick" and still not post any pics?

Argh - PLEASE PLEASE PLEASE answer me 1 question:
if you are looking top down on the unit in a rectangle view where the amber light is facing to the right side.
Where is the fan located and positioned? Is it blowing towards the LED from the left side or is it running across the width? Which direction is the air flow?

Please at least give me this Christmas Wish!?!?


Thanks,
Rob

[liqwidsky]

Haha alright I promise I'll post pics today. I was going to wait until I finished modding it but that could take a while since I have to order some supplies.

To answer Rob's question about the fan, it's a blower-style fan mounted against the top of the plastic housing above the wall plug opposite the led. There's a piece of aluminum that creates a thin air channel from one side to the other (it's about as tall as one of those circular holes in the intake or exhaust area), and in the middle of this channel there's a heatsink screwed into the aluminum piece, which gets blown on by the fan and takes most of the heat out of psu, towards the exhaust above the led. The aluminum channel is then coated with a ton of thermal compound on the other side where it makes contact with two thick pieces of aluminum surrounding the psu components, with the hottest components bolted directly onto these pieces.