VOGONS


First post, by Dochartaigh

User metadata
Rank Member
Rank
Member

I have a ~2000 Dell Dimension XPS T700r (also a T450 maybe 1-1.5 yrs older). These are supposed to have proprietary power supplies and you can't just drop in a regular ATX power supply. So I bought an adapter cable "Athena Power CABLE-DELL-X ATX 6" 20-Pin to Dell ATX 20-Pin & AUX 6-Pin" off eBay which lists my model as being compatible:

ubwLY5Q.png
asmYeYV.png

I got it in and the little tab on the 6-pin cable is in a different spot than the original Dell cable, so unless I cut that off it won't go into the plug (and I assume they're made that way for safety). The seller hasn't written me back 2 days later... so I want to make sure I'm safe using this, or if I have to switch any wires around (and if so you'll have to tell me which ones...or I can check with a multimeter but you'll have to tell me what to look for...). Here's the adapter cable on the LEFT, and the original Dell on the RIGHT:

WGi0eEZl.jpg
8ISP9Bnl.jpg



Just in case there's anything safety-wise I need to check on the larger plug (just because I'm now paranoid because that tab is in a different place on the 6-pin...), here's the adapter plugged into my new 400w ATX power supply on the left, and the original Dell 200w on the right:

R2tivpvl.jpg

Reply 1 of 13, by Horun

User metadata
Rank l33t++
Rank
l33t++

Yes I would check the voltages. On the 6pin dell it has blue wires and the adapter one has red. One of my Dells has 3 black, two red, one orange on the P7 connector but the 20 pin is standard ATX. So Dell really changed things in some computers....

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 2 of 13, by Dochartaigh

User metadata
Rank Member
Rank
Member
Horun wrote on 2020-02-23, 00:13:

Yes I would check the voltages. On the 6pin dell it has blue wires and the adapter one has red. One of my Dells has 3 black, two red, one orange on the P7 connector but the 20 pin is standard ATX. So Dell really changed things in some computers....

Do you have any experience doing this on a computer power supply? I have a multimeter I can do basic measurements with (do it on CRT TV's and sometimes video game consoles from time to time), but these computer power supplies might be a little different....

Just simple stuff like what do I use for ground? On CRT's it's usually the entire chassis. Do I use one of the pins itself for ground? I can then touch ground with the negative probe, then stick the positive into each one of the pins on the power supply and write down the values.

In my other topic somebody posted a pinout (of only the larger 20 pin, I can figure out the 6-pin myself). But I've never tested for negative voltage before...how does that even work on a multimeter? The rest seem to be +5v, +12v, or ground so those are easy.

Reply 3 of 13, by Horun

User metadata
Rank l33t++
Rank
l33t++

Is your multimeter a Digital VM or analog type ? If your Dell PSU works hook it up to the motherboard and power it up, and set on DC volts you can stick the neg probe from your DVM into any of the black leads (GND) on the 20 pin then just check the voltages on the other pins and write them down. If you hit a -5 or -12 your DVM should show that as they can read minus volts too (unless you have a very basic one). If an analog VM then the needle will peg the wrong way. Next step is check just the new adapter using Ohms and using the standard pinout for ATX 20pin (if your new PSU is using standard colors: Black GND, Red 5, yellow 12, orange 3.3, purple +5VSB, white -5, Blue -12, grey PG, green PO) , check where each wire goes from the ATX 20 to the Dell 20 part and write it down. Then compare those to the original Dell 20 pin and see if they match.
Some Dells have a TFSC wire but it may not be needed...

added: Here is a Dell Dim 8100 pinout, see if it is close to your Dell PSU
https://allpinouts.org/pinouts/connectors/pow … 0-power-supply/

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 4 of 13, by Dochartaigh

User metadata
Rank Member
Rank
Member
Horun wrote on 2020-02-23, 02:26:
Is your multimeter a Digital VM or analog type ? If your Dell PSU works hook it up to the motherboard and power it up, and set o […]
Show full quote

Is your multimeter a Digital VM or analog type ? If your Dell PSU works hook it up to the motherboard and power it up, and set on DC volts you can stick the neg probe from your DVM into any of the black leads (GND) on the 20 pin then just check the voltages on the other pins and write them down. If you hit a -5 or -12 your DVM should show that as they can read minus volts too (unless you have a very basic one). If an analog VM then the needle will peg the wrong way. Next step is check just the new adapter using Ohms and using the standard pinout for ATX 20pin (if your new PSU is using standard colors: Black GND, Red 5, yellow 12, orange 3.3, purple +5VSB, white -5, Blue -12, grey PG, green PO) , check where each wire goes from the ATX 20 to the Dell 20 part and write it down. Then compare those to the original Dell 20 pin and see if they match.
Some Dells have a TFSC wire but it may not be needed...

added: Here is a Dell Dim 8100 pinout, see if it is close to your Dell PSU
https://allpinouts.org/pinouts/connectors/pow … 0-power-supply/

Thanks, that's going to be next weekends project. My multimeter is digital but it's the very simple type you can pickup at Home Depot or Lowes for $20 or so (i.e. meant more for houses and automobiles than smaller computer electronics).

Reply 5 of 13, by PC Hoarder Patrol

User metadata
Rank l33t
Rank
l33t

When you say the 6-pin adapter won't fit; have you tried it. These headers are almost never keyed now in such a way that only a specific plug fits a specific header - if you look at the back of each header pin you'll see a channel behind each one, so it doesn't matter where the tab is on the plug if you present it at a slight angle when fitting it'll slide right in. It's the wiring that matters rather than the plug, and the Athena one will do the job just fine.

As an example, I have an old Dell Slot 1 board; an OEM Intel SE440BX-3 for which I made my own adapter cable (based around the same Athena cable you bought) but the 6-pin plug I used (an old P8/P9 one from a scrap wiring loom) has the tab on the other side from the Athena one but it still fits and still works. My guess would be that the Dell-style tabbed plug isn't made now that they long since dropped these types of custom headers.

This is a good thread on Dell and their love for custom connectors A Permanent Solution to the Dell 'Fake ATX' Power Supply Problem?

Reply 6 of 13, by Dochartaigh

User metadata
Rank Member
Rank
Member
PC Hoarder Patrol wrote on 2020-02-23, 05:15:

When you say the 6-pin adapter won't fit; have you tried it. These headers are almost never keyed now in such a way that only a specific plug fits a specific header - if you look at the back of each header pin you'll see a channel behind each one, so it doesn't matter where the tab is on the plug if you present it at a slight angle when fitting it'll slide right in. It's the wiring that matters rather than the plug, and the Athena one will do the job just fine.

It physically won't fit unless I cut that tab off. There's only 1 slot for that tab to fit into the connection on the MB, and it's in the wrong spot on the Athena adapter's plug. You can actually see what I mean on the first pic from that post you linked to - only 1 cut-out for that tab.

Reply 7 of 13, by PC Hoarder Patrol

User metadata
Rank l33t
Rank
l33t
Dochartaigh wrote on 2020-02-23, 17:41:

It physically won't fit unless I cut that tab off. There's only 1 slot for that tab to fit into the connection on the MB, and it's in the wrong spot on the Athena adapter's plug. You can actually see what I mean on the first pic from that post you linked to - only 1 cut-out for that tab.

Yeah, and I have the exact same 6-pin header on my Dell motherboard with the same cut-out position, but the adapter I made still fits - that's why I mentioned the technique of angling the plug into place.

Dell 6-Pin 01.JPG
Filename
Dell 6-Pin 01.JPG
File size
698.75 KiB
Views
2551 views
File license
Fair use/fair dealing exception
Dell 6-Pin 02.JPG
Filename
Dell 6-Pin 02.JPG
File size
698 KiB
Views
2551 views
File license
Fair use/fair dealing exception

All you do is present the plug to the header at an angle so that the tab hooks underneath the piece of plastic which normally blocks it, then you rotate forward and push down at the same time and the plug will slide right on

Dell 6-Pin 03.JPG
Filename
Dell 6-Pin 03.JPG
File size
1.09 MiB
Views
2551 views
File license
Fair use/fair dealing exception

and the same technique, but with the standard P8/P9 connectors

P8P9.png
Filename
P8P9.png
File size
282.75 KiB
Views
2551 views
File license
Fair use/fair dealing exception

Reply 8 of 13, by Dochartaigh

User metadata
Rank Member
Rank
Member
PC Hoarder Patrol wrote on 2020-02-23, 21:36:

Yeah, and I have the exact same 6-pin header on my Dell motherboard with the same cut-out position, but the adapter I made still fits - that's why I mentioned the technique of angling the plug into place.

I gotcha now - thanks for the detailed explanation! Yeah, I'm sure I can jam it in there (or more easily just cut that tab off 😉 . But I'm still worried that the tab is there for a reason and if I plug it in without testing everything beforehand it's going to go up in smoke! Honestly, I might just try it - I'm so pissed at these Dell computers (~30 installs of WIndows 98 so far -not joking in the least- and not a SINGLE stable build yet), so if I fry one I'm not going to cry too much (although they were expensive off eBay!)

Reply 10 of 13, by Horun

User metadata
Rank l33t++
Rank
l33t++
PC Hoarder Patrol wrote on 2020-02-23, 21:36:

and the same technique, but with the standard P8/P9 connectors..

Great explaination!

Hate posting a reply and then have to edit it because it made no sense 😁 First computer was an IBM 3270 workstation with CGA monitor. Stuff: https://archive.org/details/@horun

Reply 11 of 13, by chinny22

User metadata
Rank l33t++
Rank
l33t++

One day if your looking for something to do
See those 3 pair's of solder pads to the left of the ATX connecter? Moving the ATX connecter over to use these makes it a standard ATX pinout again!
Someone found this out here few years ago 😀

Reply 12 of 13, by Dochartaigh

User metadata
Rank Member
Rank
Member
chinny22 wrote on 2020-03-10, 13:28:

One day if your looking for something to do
See those 3 pair's of solder pads to the left of the ATX connecter? Moving the ATX connecter over to use these makes it a standard ATX pinout again!
Someone found this out here few years ago 😀

I do happen to own a Hakko-clone desoldering gun...

Reply 13 of 13, by chinny22

User metadata
Rank l33t++
Rank
l33t++

Here's the full post, I've 2 guilty dells on the to do list myself
A Permanent Solution to the Dell 'Fake ATX' Power Supply Problem?