Dell RM112 235W 80+ Gold PSU

PSUs: The source of DC power for all components in the PC & often a big noise source.

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drees
Posts: 157
Joined: Thu Jul 13, 2006 10:59 pm

Post by drees » Wed Jul 14, 2010 3:47 pm

Nice mod - looks tempting to replace my Pico PSU with - the brick mine came with makes a horrible noise when the fan spins up which happens whenever the CPU gets to full load...

Looks like you can find them for $34/shipped on eBay - pretty inexpensive, too!

Robaird
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Location: Florida

pin out

Post by Robaird » Thu Jul 29, 2010 6:41 am

For those on the fence interested in more information, I can also confirm that these PSUs follow conventional wiring colors so you can use standard atx pinouts (search google--I like the ones at pinouts DOT ru & helpwithpcs DOT com & wikipedia; I'm not allowed to post url's yet, sorry)--with a couple of caveats discussed a few paragraphs down.

You should probably be able to use an old 20 or 24 pin connector (and wires cut to the appropriate length for the case). I say 20 or 24 pin because although 24 pin is ATX 2.x, apparently most ATX 2.x motherboards will still accept the older 20 pin configuration. The extra 4 pins are for additional power demands. But this is not a psu for a Core i7 or i9 system with a good graphics card (not even an efficient ATI 5850 or Nvidia 460). You may also need to do some a little extra soldering for extra sata connectors etc.

Now for the caveats. This psu, being rated for 235 watts, was not really designed for a true 24 pin plug so there are a couple of wires missing--which should not be a problems unless you are really pushing the amps on those particular rails. I don't have the psu in front of me, so I don't remember if it is missing a 3.3 (orange) or 5 volt (red) wire. As I did not realize the Intel Jetgyser motherboard could use a 20 pin plug until after I did the soldering, I just soldered two wires onto one of the existing psu wires so I would have enough to fill all the pins. Of course, I'm still limited to the same amount of amps on that rail, but there is no way I'll ever come close to using it up with the system I built (see earlier post).

There are a couple of other wires you will not have--but these are not needed. They include, if memory serves me correctly, the white wire for pin 20 (totally optional, used for old atx 1.2 or earlier mbs) and the 3.3 sensing wire (brown) that cohabits with the orange wire on pin 13. Just cut the brown wire on the atx plug you salvage from somewhere and you will be fine. I have my computer running non-stop and have never had a single power or other problem (including no ground faulting or similar problem described by another poster).

For those with limited soldering experience (as I had before this project), cut the atx connector to leave a little more wire as you will need for your case (if I remember correctly, I probably left about 7 inches because I had a very small case). Then slip on some heatshrink tubing (I used 1/8" diameter adhesive lined tubing, which I cut to 1" lengths), strip wire about 1/2" and bend the ends of the striped wire to make 1/4" "U's", slip the corresponding ends from the atx connector and psu and twist each end to make a mechanical joint just in case your solder (and adhesive shrink tubing) fail; tin the tip of your soldering iron with some solder (I used 60-40 Rosin Core Solder for the whole job), solder by staking the twisted wires on top of the soldering iron, and placing the solder on top so the heat conducted through the wire melts the solder--if you cheat and heat the solder directly, called cold soldering I believe, you risk the soldering breaking loose--but for those that can't resist the temptation, the mechanical connection will probably save you). If it doesn't seem to be working, you probably forgot to tin the tip of the soldering iron--which makes it much more heat conductive. Then use the solder iron (below the tinned tip) to carefully and quickly melt the shrink wrap down--being careful not to come in contact with the wires, which will quickly melt away exposing the wire and creating short, shock, and fire hazards.

Once you do 20+ wires, you won't be a complete novice anymore! (probably took me an hour for the first 2 wires--b/c I hadn't tinned the tip; and an hour for the remaining 22 wires). It's not a big project if all you do is change the atx connector, add some sata connectors, and leave the case and fan stock.

chinna_n
Posts: 82
Joined: Fri Mar 31, 2006 3:49 pm
Location: Seattle, WA

Re: Dell RM112 235W 80+ Gold PSU- Now it is Silver

Post by chinna_n » Thu Dec 23, 2010 8:56 am

Few days ago I bought this power supply and It seems Dell changed the certification for this Power supply. Now it's label says silver, otherwise it is exactly same as what is shown in this thread. Though I do not see a date stamp anywhere, it looks like more recent model.

Also, the fan inside is not ADDA anymore. It is AVC DS08015B12M which is rated at 12v 0.48A 32.1CFM. This became noisy fan (though it is running very slow) in my build. I need to check if I can get away without this fan and provide some airflow from main 120MM fan.
Last edited by chinna_n on Wed Dec 29, 2010 8:48 am, edited 1 time in total.

chinna_n
Posts: 82
Joined: Fri Mar 31, 2006 3:49 pm
Location: Seattle, WA

Re: pin out

Post by chinna_n » Sun Dec 26, 2010 9:04 am

Robaird wrote:For those on the fence interested in more information, I can also confirm that these PSUs follow conventional wiring colors so you can use standard atx pinouts (search google--I like the ones at pinouts DOT ru & helpwithpcs DOT com & wikipedia; I'm not allowed to post url's yet, sorry)--with a couple of caveats discussed a few paragraphs down.

You should probably be able to use an old 20 or 24 pin connector (and wires cut to the appropriate length for the case). I say 20 or 24 pin because although 24 pin is ATX 2.x, apparently most ATX 2.x motherboards will still accept the older 20 pin configuration. The extra 4 pins are for additional power demands. But this is not a psu for a Core i7 or i9 system with a good graphics card (not even an efficient ATI 5850 or Nvidia 460). You may also need to do some a little extra soldering for extra sata connectors etc.

Now for the caveats. This psu, being rated for 235 watts, was not really designed for a true 24 pin plug so there are a couple of wires missing--which should not be a problems unless you are really pushing the amps on those particular rails. I don't have the psu in front of me, so I don't remember if it is missing a 3.3 (orange) or 5 volt (red) wire. As I did not realize the Intel Jetgyser motherboard could use a 20 pin plug until after I did the soldering, I just soldered two wires onto one of the existing psu wires so I would have enough to fill all the pins. Of course, I'm still limited to the same amount of amps on that rail, but there is no way I'll ever come close to using it up with the system I built (see earlier post).

There are a couple of other wires you will not have--but these are not needed. They include, if memory serves me correctly, the white wire for pin 20 (totally optional, used for old atx 1.2 or earlier mbs) and the 3.3 sensing wire (brown) that cohabits with the orange wire on pin 13. Just cut the brown wire on the atx plug you salvage from somewhere and you will be fine. I have my computer running non-stop and have never had a single power or other problem (including no ground faulting or similar problem described by another poster).

For those with limited soldering experience (as I had before this project), cut the atx connector to leave a little more wire as you will need for your case (if I remember correctly, I probably left about 7 inches because I had a very small case). Then slip on some heatshrink tubing (I used 1/8" diameter adhesive lined tubing, which I cut to 1" lengths), strip wire about 1/2" and bend the ends of the striped wire to make 1/4" "U's", slip the corresponding ends from the atx connector and psu and twist each end to make a mechanical joint just in case your solder (and adhesive shrink tubing) fail; tin the tip of your soldering iron with some solder (I used 60-40 Rosin Core Solder for the whole job), solder by staking the twisted wires on top of the soldering iron, and placing the solder on top so the heat conducted through the wire melts the solder--if you cheat and heat the solder directly, called cold soldering I believe, you risk the soldering breaking loose--but for those that can't resist the temptation, the mechanical connection will probably save you). If it doesn't seem to be working, you probably forgot to tin the tip of the soldering iron--which makes it much more heat conductive. Then use the solder iron (below the tinned tip) to carefully and quickly melt the shrink wrap down--being careful not to come in contact with the wires, which will quickly melt away exposing the wire and creating short, shock, and fire hazards.

Once you do 20+ wires, you won't be a complete novice anymore! (probably took me an hour for the first 2 wires--b/c I hadn't tinned the tip; and an hour for the remaining 22 wires). It's not a big project if all you do is change the atx connector, add some sata connectors, and leave the case and fan stock.
Hi Robaird,

Thanks for providing good details. This was really helpful when soldered ATX connector. BTW I also soldered Molex to support HDDs using 21-24 PIN which are not being by my mother board.

Chinna

BillyBuerger
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Re: Dell RM112 235W 80+ Gold PSU

Post by BillyBuerger » Sat Jan 08, 2011 7:26 pm

Small 24 Pin to 20 Pin ATX Converter Adapter for HP Slimline

Oh wow, it looks like someone actually makes an adapter for the small ATX power connector on the RM112 now. It's listed under HP but I believe HP and Dell use the same connector. I might have to pick one up just to to make sure. I was also eyeing the RM110 which is a larger PSU than the RM112 but still uses the small connector. I can tell it's not standard ATX still in size but I can't find anything that specifies the exact size. Will the two holes line up at least?

chinna_n
Posts: 82
Joined: Fri Mar 31, 2006 3:49 pm
Location: Seattle, WA

Re: Dell RM112 235W 80+ Gold PSU

Post by chinna_n » Wed Jan 12, 2011 11:01 pm

Very good find. Wish it was found before I soldered 30+ wires...

Oh well I saved $15 for 2 hours of my work... :lol:

okashira
Posts: 4
Joined: Sat Mar 12, 2011 10:16 pm

Re: Dell RM112 235W 80+ Gold PSU

Post by okashira » Wed Oct 23, 2013 5:36 pm

Hello,

I purchased one of these PSU's myself off ebay planning to use in a mini ITX FreeNAS build.

I also purchased an adaptor here: [link removed by mod]

to adapt the ATX power connector.

The adaptor finally came in, and I plugged everything into the board and one sata drive (plan to rewire for 6 sata drives)

As soon as I plugged it in, a noise immediatly came from the PSU, I could see sparks from behind the fan, then a loud POP; followed by silence.

Does anyone know if the adapter I bought is the wrong one, or was my PSU bad?

Would be good to know before buying another PSU :-D

edh
Posts: 1621
Joined: Mon Mar 17, 2008 1:49 pm
Location: UK

Re: Dell RM112 235W 80+ Gold PSU

Post by edh » Thu Oct 24, 2013 8:38 am

I would suggest you try testing any new PSU with a paper clip first without any components. You can Google for how to do this. I would suggest returning the broken PSU as faulty first and then testing the replacement without components using a paper clip.

okashira
Posts: 4
Joined: Sat Mar 12, 2011 10:16 pm

Re: Dell RM112 235W 80+ Gold PSU

Post by okashira » Fri Oct 25, 2013 9:41 am

edh wrote:I would suggest you try testing any new PSU with a paper clip first without any components. You can Google for how to do this. I would suggest returning the broken PSU as faulty first and then testing the replacement without components using a paper clip.
Edh,

Thanks for the tip. I want to clarify what adapter I bought since it seems my link was removed.

"Original ATXPowerSupplies Small 24 Pin ATX to 20 Pin ATX Connector Converter Adapter for HP Slimline Power Supplies"

I guess trying to return my PSU wouldn't hurt, but I was wondering if it's possible that the adaptor I got is wired wrong? It says for HP PSU's but it fit this dell PSU connector like a glove.

Where can I get the PINOUT for a RM112, and compare to a standard ATX connector to verify?

Has anyone tried an HP slimline adapter with a dell?

flyingsherpa
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Re: Dell RM112 235W 80+ Gold PSU

Post by flyingsherpa » Mon Oct 28, 2013 8:24 am

okashira wrote: Where can I get the PINOUT for a RM112, and compare to a standard ATX connector to verify?
Has anyone tried an HP slimline adapter with a dell?
I modded an RM112 a few years ago (still use it, works great). IIRC, the wire colors match the normal ATX PSU wire spec. I verified each with a voltmeter when I was soldering on a new connector (minus a few colors it was missing). So just google the regular ATX spec and/or see if your adapter lines up the correct colors (does the adapter have colors?).

okashira
Posts: 4
Joined: Sat Mar 12, 2011 10:16 pm

Re: Dell RM112 235W 80+ Gold PSU

Post by okashira » Mon Oct 28, 2013 3:18 pm

flyingsherpa wrote:
okashira wrote: Where can I get the PINOUT for a RM112, and compare to a standard ATX connector to verify?
Has anyone tried an HP slimline adapter with a dell?
I modded an RM112 a few years ago (still use it, works great). IIRC, the wire colors match the normal ATX PSU wire spec. I verified each with a voltmeter when I was soldering on a new connector (minus a few colors it was missing). So just google the regular ATX spec and/or see if your adapter lines up the correct colors (does the adapter have colors?).

Yeah the adaptor is colored.

Thanks for the idea with a voltmeter. I can use the paperclip trick to power it on and make my own pin put. There should only be a few different pins:

+12
-12
+5
-5
+3.3
-3.3
ON SIGNAL?
GROUND

Anything I missed or added?

I will go ahead and procure a new RM112 and check the adaptor wiring before using again.

Actually, I was planning on using this PSU in a LIAN LI PC-Q25... I just realized this PSU is pretty long so I better make sure it fits :-D

okashira
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Joined: Sat Mar 12, 2011 10:16 pm

Re: Dell RM112 235W 80+ Gold PSU

Post by okashira » Thu Nov 21, 2013 6:31 pm

My new RM112 came in and gave it another go. This time I inspected the wiring of my adaptor.

Turns out the adaptor was completely wrong. Only about 4 wires were correct, out of pure luck.


I was able to repin the adaptor just by matching colors and it works perfectly.

Amazingy the motherboard I plugged the first one into is just fine. The psu is fried, though.

solitus
Posts: 6
Joined: Sat Apr 23, 2011 6:28 pm
Location: Sydney, Oz

Re: Dell RM112 235W 80+ Gold PSU

Post by solitus » Thu Dec 19, 2013 1:50 am

I just picked up a couple of the L255EM-01 Dell 255W gold 80-plus PSU's and they also have the same mini-ATX connector.

I found a pinout for the dell mini-ATX connector here:

http://www.tomshardware.com/forum/28625 ... video-card

It's this:

Code: Select all

---------------------------------------------------------------------------------------------------------------------------------
24 pin  Dell mini-atx pinout

1       2       3       4       5       6       7       8       9       10      11     12
GRND    N/C     +12V    +3.3V   GRND    GRND    +12V    +5V     GRND    +5V     +5V    +5V

13      14      15      16      17      18      19      20      21      22      23     24
GRND    GRND    +3.3V   +3.3V   PWR_OK  GRND    +12V    -12V    GRND    PS_ON   +5V    +5V

---------------------------------------------------------------------------------------------------------------------------------
Sounds like Dell's OEM uses standard colors for the wires. I also ordered one of these connectors a couple of days ago to adapt mini-ATX PSU to 20/24-pin ATX motherboard.

http://www.ebay.com/itm/Athena-Power-CA ... 58a8a5a12f

My plan is to modify the pinout of the adapter to work with the Dell PSUs, so it'll just be a plug and play operation - although I'll check the first one carefully with a multimeter :)

edit: bah, tab's don't render properly in the "code" tags lets try spaces

solitus
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Location: Sydney, Oz

Re: Dell RM112 235W 80+ Gold PSU

Post by solitus » Fri Jan 24, 2014 1:03 am

My adapter worked - there's a couple of changes needed to the pinouts to go from the Dell 24-pin miniATX to a standard 24-pin ATX.

I used the ebay adapter as the base, then removed all the pins from the miniATX connector using a jewellers screwdriver.

The Dell colours are close to stock.

Red = +5V
Orange = +3.3V
Black = Ground
Blue = -12V
Green = power-on
Purple = +5V
Gray = power ok signal
White = +12V

The white is a gotcha - the 3 white ones on the Dell PSU connector are all +12V. On a regular ATX connector, those wires are Yellow, and there's a single white used for other purposes. The Dell PSU's don't use the single white on an ATX connector - its the no-connection on Pin 2, so cut that off (its optional in the ATX spec - unused in current ATX 2.3).

The differences come in the numbers of wires.

The Dell PSU is short one orange - so I spliced pins 1 and 13 together on the ATX end so they share a single wire out of the Dell PSU
The Dell PSU has one extra +12V wire - so I wired that into another of the +12V ones in the ATX adapter harness (this was probably unnecessary).

While I was at it I also swapped the fan in one of the PSU's I bought for an old and very quiet Silverstone Suscool I had in the cupboard from when I was using them in an Antec minuet case. The stock fan does make a slight whirring noise, but with the change in fan the PSU is inaudible.

I'm about to swap one of the Dell's into my home server (4-core Xeon X3450 with 32G of RAM, LSI HBA disk controller, 4x 2T hdd, 2x 2.5" 320G HDD, 2x SSD) - should be interesting to see how much improvement I get over the Antec VP350 its got. Normal idle is 59-61W (fluctuates as its running Xen hypervisor).

I can report that with the Dell PSU, a 120mm case fan, and a Hyper TX3 cpu cooler, my spare i5-650 machine idles at 21W at the wall, which is a good start!

The pic is of:

Unmodified ebay mini-ATX to ATX 24-pin adapter
SATA male to Molex Female plug (the Dell PSU has no Molex connectors, so this is needed for anything which needs a regular Molex)
Modified mini-ATX to ATX 24-pin adapter (you can see the yellow elec-tape on the 2 splices mentioned above, and the cut white wire at the ATX end).
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