Startup of server PSU "N7K-AC-6.0KW"

[Gady159]

Now i came with idea that i could try connecting random digital pins to groud (not short, like 100ohm resistance to prevent short circuit currents) idk if its good idea but maybe i could find that pin faster... or it can be 2 pins at the same time and i will never find it

[reklm]

do what Thunderbolt said it is safe and it worked for him.

[Gady159]

Yes, sorry Thunderbolt... i somehow completely missed your comment about your testing method..

I will try tomorow and i write update here

[Multi-kv]

There is some great information on the rcgroups-forum:

Overview Server-PSUs:
======================
https://www.rcgroups.com/forums/showthr ... r-Supplies

general procedure to find PSon and PSkill:
==============================================
https://www.rcgroups.com/forums/showthr ... r-Supplies

https://www.rcgroups.com/forums/showpost.php?

I had some success with the procedures described here. You can measure resistance between ground and each PIN on the backside and conclude its possible function. Its still guessing so you must be cautious and use at least 500 ohm or 1k resister to bridge pins. Good luck!

[Gady159]

Hi,

So i measured all pin resistance aganist GND and then power PSU on and measure each pin voltage aganist ground

Its seems there are mostly 3,5V logic and one pin 12V which can be +12Vstby

Should i try now method testing with 1k resistor? problem is that i dont know from which pin i should take 3,5V for testing

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[Gady159]

I can first try 3,5V pin pulling down by 1K to GND and then reverse pulling UP 0V by 1k to some 3,5V pin (supply?)

[Gady159]

Yeeeeees guys i did it !!!!

So i follow instructions and i excluded every 0V pin and connected 470R resistor to GND and i was able to find exact pin which turn PSU to the standby mode.

After turning on switch on front panel PSU (50V will turn on)

So i make it (to my surprise very fast)

Thank you guys all of you a lot.

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[Multi-kv]

Congrats for your success - glad we could help here.
Typically its a pin with 1 - 10k resistance to gnd that you have to bridge.

Now you can try adjusting the output voltage - but this is much more difficult in most cases.

[Gady159]

Yes, thanks all of you..

I suppose there will be some IC or O-AMP with feedback with resistor divider which i would need to change to fool PSU to think there is still good voltage at the output . But there can be problem with that, there are two supplies somehow matched so they could give same current to the load (some current sharing).

Sometime i will definetly look at that, now am glad that PSU works

[Thunderbolt]

Yes, thanks all of you..

I suppose there will be some IC or O-AMP with feedback with resistor divider which i would need to change to fool PSU to think there is still good voltage at the output . But there can be problem with that, there are two supplies somehow matched so they could give same current to the load (some current sharing).

Sometime i will definetly look at that, now am glad that PSU works

für my 48V PSUs i found the 2.5V reference and made that adjustable, that safer since it does not change the gain of the feedback loop and you can regulate down to 0V if you find and disable the undervoltage shutdown