Quote from: thesmokingman on February 01, 2016, 09:29:48 PM

Quote from: J4bberwock on January 30, 2016, 07:03:01 PM

Quote from: generalt on January 30, 2016, 06:37:49 PM

So I ordered a pair of DPS-2000BB from a server supply company and I finally got them yesterday. They sent me two Rev. 3 which I think to myself great under Rev. 9 so it should be good for the volt mod and all that fun stuff. Unfortunately when I plug the breakout board to the pair of PSU and connect the power cable I get absolutely nothing. I take the exact same setup, same power cord, same outlet and same breakout board and plug it into a pair of Rev S8M and it works perfectly. Has anybody else had any experiences with Rev 3? I could understand if one of the power supplies was dead, but neither of these power supplies powered on at all.

I believe I never got an older revision than s5 or s6. To try them individually, you can plug the bottom one to the dual breakout hoard. This way, even voltage adjust works with a single PSU.
The pinout for the PSU have to be the same on all revisions, or you'll have trouble on the servers. If the breakout board works with one revision, it'll work on all unless the very old revisions are using another pin combined with the one I use to turn on the PSU.
Or you may have 1 or 2 dead PSUs.

I purchased 32 of these PSUs from a dealer on eBay and they are all REV1-REV4 and they all work fine for me using the dual BB. The only issue I saw was at the highest setting, I was only getting 12.30~.40v. This was resolved by tweaking the internal VR501 pot an 1/8th of a turn to the left. Other than that, I haven't had any issues with my older REV PSUs. Mine all end with an "A" though as J4bberwock has mentioned, so that could also be an issue.

Near where you plug in the power cord, you should see two glass domes there with AC written under one and DC written under the other. Do you see either one (I think AC should light up first) light up when you connect the power cable? If not I would say you have bad PSUs. Out of the 32 I tested, the one bad PSU I did have would power up (green light for AC & DC), but would shut down when placed under load. Both the green light for AC and DC would go out, and the volts would drop down dramatically on the LCD display.

@J4bberwock - Could I have adjusted the external pot on your dual BB to correct the issue of the PSUs only putting out 12.30v? I only ask as I adjusted the small pot on the bottom left of the breakout board, but didn't notice a change in volts on the LCD screen or my multi-meter (I was turning the external pot to the left). As mentioned above, I manually adjusted the pot on the inside as I was afraid to keep turning the external one of the BB.

The external pot on the breakout board will only have effect if the PSU is from a revision that can be adjusted
I personally tested revisions from 6 to 10, and 6 to 8 are working. Can't remember if the S9 worked too.
Clockwise will give more offset from the stock value of 12.2v
Counterclockwise will reduce offset to a point you should reach close to stock value.
Setting the external pot in middle position without touching the internal ones should give you 11.8v undervolt and 12.8v overvolt