Server Powersupply mod


Active member
If +vref is the same level for all regulators I wonder if you might have to provide the +12v reg . with its own seperate +vref in order to increase its output only, to the desired 13.6 v, just an idea..


Staff member
Applying 12V to pin 44, 0V to 46, gives 2.5V on 45.

EDIT: Changing R34 from 910K to 1M did not alter anything.
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Active member
With LM324n, looks like if pin 5 goes low then output pin 7 also goes from high to low and pulls current through diode and 36k from pin 38 ? Wonder what is on pin 38 , maybe the main regulator.


Staff member
I was having a lot of trouble printing a new cover....

These all stopped printing with jammed filament about half way through the print.
In the process of the black PLA prints, I had to pull the hot end apart to remove the filament and found it was a bit loose. That was the problem, I hoped. But no!
So, maybe the black is the problem?
Well, you can see that changing to the grey did not fix it.

To do these prints, I have changed the slicer program used. The slicer is the program that converts the drawing .stl file into the .gcode the printer understands. This new version has a setting to keep the holes the correct size. Using the older version of the slicer, the holes turned out smaller that set so I'd fiddled the hole sizes to fix that. The setting in the slicer does the "fiddling" for me now. As a result of using the new slicer I may go and redo the old files.
Anyway, it turns out the problem with the print stopping looks to the the retraction setting in the new slicer. The retraction is the filament being pulled back into the printer a bit so there will not be melted filament oozing out while the head is moving and not printing.
Mr Google showed one cause of the filament jamming could be the retraction set too high. If it is, more heat gets transfered up into the cold part of the hot end eventually causing the filament to melt too early so causing a jam.
The retraction was set at 6.5mm and a change to 2.5mm fixed it :)

This version starts out with black for 3 layers, then I change to orange for a bit, then back to black.

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Staff member
A worthwhile simple mod on the R2Z-6400P-R 28Amp version is to unplug the two 12V fans and hook them onto 5V. I kust taped the connectors together, bent a couple pieces of wire (resistor lead) into U shapes so they plug both "12V" connections together and same for the 0V. Then soldered a length of hookup wire to these links and ran them to the PS 5V and 0V connections.
Now, the fans run quietly, instead of as sirens!


Staff member
I'm thinking of using some PVC down pipe for the case as it will be a lot easier and faster to produce. There will have to be a few adapters made to fit as the pipe is bigger the the power supplies, but here is the first "working" effort.
The front is similar to the earlier ones...

but being removable will make wiring a lot easier.


It fits ok, and will have screws in from the sides, top and bottom.


Staff member
Here it is all printed out.

There is a front, spacer and rear feet.

The spacer has air channels.

Feet can be fitted at the rear to level it.


I have not installed the 12V sockets as yet.

The fully 3D printed case may be neater but it takes a long time to print.
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Staff member
Here are the steps to wire it up to a connector that has been cut off the power supply cradle chassis.
First, the power switch and LED. Note the 220R resistor in line with the LED.

Next, the USB sockets. I have included a 5A Polyswitch, and no USB resistors.

Now to thea12V. I used Jaucar flat speaker wire as it is very flexible, and has a lot of copper.

The fans normally run on 12V and if you like sirens, you can keep it that way. I prefer a quieter supply so here are the steps to change to 5V operation.
First, take the PS top off.
The fans need to be unplugged. There will be white gunk that needs to be cut to free the plugs.
A couple of wire links bent to fit..

and the connectors wired together.
then secured with heat shrink or tape
Finally, with the top put back and the mounting sleeve fitted, the fan wires can be attached to the socket.

It works :)

( I used my soldering iron to "drill" screw holes in each side to hold the front on.)
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