I have two HP DPS-1200FB-1 Platinum and after soldering the 1K, 1W resitor, I tested each one but they are not working.
When I plug the power cord , the fan starts spinning very quietly but the LED is off and the voltage is around 0.08V.

I followed the following threads :
http://studio939.blogspot.pt/2016/01...ystem-for.html

http://www.rchelination.com/setting-...-power-supply/

Any help will be much appreciated.

Thanks in advance,

Luis

Same as this mod?
https://github.com/raplin/DPS-1200FB

Rick

Originally Posted by rampman

Same as this mod?
https://github.com/raplin/DPS-1200FB

Rick

Hi Rick,

Not quite exactly.

I want to build one 24V Power source using this two power supplies in series.

All of the hacks/mods I've seen so far are using the normal DPS-1200FB, however I am using the DPS-1200FB-1 Platinum which have a greater efficiency.

As of my understanding, after soldering the resistor the power supply should work and output 12 v, which is not my situation.

I'm testing each power supply at a time, but unfortunately without any luck so far.

Luis

Hi Luis.

I recently modded a dps-750 that is almost exactly the same as the dps-1200. I followed the same advice you did and used a 1K 1W resistor and nothing happened. In order to trigger the power supply to turn on I had to use a 330 ohm 1W resistor.

Hope this helps.

Originally Posted by rcja

Hi Luis.

I recently modded a dps-750 that is almost exactly the same as the dps-1200. I followed the same advice you did and used a 1K 1W resistor and nothing happened. In order to trigger the power supply to turn on I had to use a 330 ohm 1W resistor.

Hope this helps.

Hi rcja,

You are right , it should be a resistor value problem.
I shorted the resistor (same as put a wire between pin 33 and 36) and both power supplies start working.

I assume i had to use a resistor to limit the current below 100mA.

I will try with one 330 ohm resistor and I'll post the result.

Thank you,

Luis

Tell me please, I put a resistor, the LED blinks, the power is on, but the fan is spinning very poorly. How to solve this problem?

I think the fans only come on when the PSU gets super hot - my DPS-1200FB works like that - they really come on when it heats up.

Does anyone know which one of the pots adjusts the voltage? They are not the same (see attached pic) as the HeliNation ones - the original DPS-1200FB has three pots and the "DPS-1200FB-1 A" has 5 pots... so which one adjusts the voltage?

If you are not sure what value resistor is going to work, get a trimpot resistor of 1k to 2k, like this:

https://www.ebay.co.uk/itm/2k-ohm-Po...-/183045473909

Short the middle lead and one end of the resistor together and use it to find the correct value required.

Don't use one of those multiple turn type trimmers, it's too fiddly for this application and the precision isn't necessary.

You can either leave it in place, or substitute it with a fixed resistor of the same value.

How can I figure out what pot raises the voltage? I don't feel like doing this by trial and error. Is it even a good idea to raise the voltage on this PSU model?

I figured it out by trial and error - for anyone else who's using this same PSU, it's pot number 4 from the left and I got max Voltage to be 12.53V on one PSU and 12.60V on the other - so not quite perfect and the charger will buck-boost towards the end of the charge, but it's close enough. These PSUs do seem to run cooler than the non-94% efficiency ones which I have.

Oh, and 330 Ohm 1 Watt resistor is enough to power them on.

Originally Posted by prokyon

I figured it out by trial and error - for anyone else who's using this same PSU, it's pot number 4 from the left and I got max Voltage to be 12.53V on one PSU and 12.60V on the other - so not quite perfect and the charger will buck-boost towards the end of the charge, but it's close enough. These PSUs do seem to run cooler than the non-94% efficiency ones which I have.

Oh, and 330 Ohm 1 Watt resistor is enough to power them on.

Hi prokyon, I think you might have mistook what I was on about.

The trimpot I was referring to, was to be mounted in the place where the 1W fixed resistor normally goes.

The purpose of that is so you could adjust it, until the PSU reliably turns on. Whatever you end up with, is the 1W resistor value you choose, then substitute that for the trimmer.

The purpose of that, is so you don't have to keep changing resistors until you find the right one, saving time and heat damaging the solder pads.

As for increasing the output voltage, I have two Revolectrix PL8 chargers that run on anything between 10V to 32V DC. I prefer to run them up to 24V DC, leaving a bit of "headroom" instead of at near enough their maximum input voltage. I do this for reliability and safe operation of the (expensive) chargers.

I have left my HP DPS's at their original output voltages, again for reliability, IMO there is no need to wring every possible volt out of them. When you increase the output voltage, you are also approaching the maximum limits of some of the electrolytic capacitors. Should the output voltage have a spike, that transient could damage the electrolytic and tantalum capacitors if it exceeds their maximum operating voltage. They don't take to kindly to over voltage conditions.

Hi Guys... I'm having this Issue... I use a jumper from Pin 33 to 36, and the PSU is enable and I can get 12.34V but when I conect my charger I try to charge a 6S 5000 mAh battery at 10 amps (2C) but the charger doesn't goes over 7.4 AMPS... Any Idea on how can I raise the Amps???

Originally Posted by PoncioPilot

Hi Guys... I'm having this Issue... I use a jumper from Pin 33 to 36, and the PSU is enable and I can get 12.34V but when I conect my charger I try to charge a 6S 5000 mAh battery at 10 amps (2C) but the charger doesn't goes over 7.4 AMPS... Any Idea on how can I raise the Amps???

What charger?

Hi,

I got a HP 1200FB A with a Breakoutboard atx64p6-n02 ver003 and the problem is ;

I plug the power outlet;
The LED on the PSU doesn't turn on;
The Watt display on the Breakout board doesn't show anything;
The LED on the brekaout board blink green,red,bleu......
The fan on the PSU turn a little bit
The GPU connected to it doesn't turn on ;(

I have tried 3 different PSU with 2 different breakout board = same result.

Thank you in advance for your help

Today I played with my pair of DPS-1200FB-1 PSU. So I tried a 1K resistor, it would not turn on, then a 750Ω (the two most common resistances I found people using in my search last night), same, nothing out the main output. Then I grabbed my resistor decade box and connected up with a ammeter.

Open 3.1v 0mA
1k 0.58v 0.5mA
800 0.54v 0.57mA
600 0.34v 0.57mA
500 0.29v 0.59mA
200 0.12v 0.62mA
100 0.06v 0.63mA
0 0.001v 0.65mA

My two power supplies turn on at 500Ω or lower, indicating it needs under 0.3v to trigger the turn on. As can be seen there is very low power and a wire works fine.

When the main output is off, the 12V standby (SB) and the 5V output(s) on the bottom of the connector are on.