I was hoping an HP Server tech would answer my question. Since that hasn't happened yet, more detail is needed from me:
The power supply isn't involved here; P2 feeds power to the back plane, as mentioned in my question, which feeds power in turn to the 4 10,000 rpm SCSI drives, because these drives have 80 pins, (no separate power pins as do the common IDE drives, and some SCSI drives). P2, as I mentioned, has 14 pins, and its cable has the colors mentioned.
The reason I guessed at the usage per color is that I have no wish to blow the back plane (irreplaceable) or these LVD Ultra 160 MB/S fast drives (essentially irreplaceable) made by IBM for HP.
So, even though the power supply information you gave a link for is interesting, it only applies IF HP decided to follow the ATX color code in 2000. And as I said, this connector only has 14 pins, and ATX has (usually) 20.
If you can give me a link for the pins on the HP P.S. module, D8520, rated at 349 W, which has 3 connectors with 14 pins each, and tell me which of the many black, brown, yellow, red, white and purple, turn on the P.S., that would be interesting. Too bad there is no green, and there at least 3 of each color. I've decided to use a large ATX supply, if the connections to the back plane can be found.
I do thank you for trying, and I wasn't aware the many more complicated configurations.
And please, anyone else reading my query, disregard my comment about the 4 red, black, and yellow wires for IDE connectors; that's another, adjacent cable. My mistake.
I wonder when the ATX 'standard' will really take effect. There are too many ATX power supplies with varying color schemes.
You'll probably have better luck finding and HP server tech on... the HP forums rather than the forums of a random computer tech site.
What I linked you to shows the layout of the ATX, SFX and WTX standards. I couldn't find out which the HP D8520 is or is it is a different one.
Unfortunately I don't know anything about this power supply and don't exactly understand why you need to know the wire layout because I don't understand the setup you are trying to do. Trying to explain more would probably end up being a waste of time on me though lol. I hope you can find someone with more knowledge to help =)
just for the example:
If I have an old server with no use and I want to use it's drives to boost up my home pc:
I would take the dirve bay with 4 ultra fast SCSI drives in minimum cost, build up a little raid that would be insufficient for any server - but for gaming machine it would be awsome.
problem is, the power supply in the server is'nt going directly to the back rack of the SCSI drives - it is plugged to the main board, from the M-board there is another cable powering the bay.
So I have no idea what power connectors I should plug in.
no HP forum will ever describe this - they don't want you to know that.
another alternative is to buy some connectors that replace the 80 pin SCSI to 68 pin+power - but this option is very expensive which spoil the whole idea.
If the server itself still working, I would suggest plug it in and test the votage with an AVO meter.
actually I would like to know it myself - I have the exact same bay. so please post the answer
Just finished soldering the last connection between an ATX connector removed from a dead mobo, and the cable that connects to the drive bay; it says P2 on the cable harness. It came from the dead servo mobo and had connectors for IDE devices, too. Then it seemed a good time to check my email. Thus the reply. The color code for the harness to the drive bay (P2) uses the same color code as an ATX P.S.
I just finished clipping the wires of the harness at P1 (mobo connector) then stripped and soldered the ends to the ATX connector from a dead PC mobo. The other end of the harness was marked P2 and connected to the drive cage. It is now ready for a live test. Plan to slip the soldered ATX connector into a small j-box once it is working.
Had 4 small SCSI drives (4 GB) and tried them with my PC first, as they had the 68 pin connector with 4-pin bergs. That told me I had a good SCSI card with BIOS, and got my feet wet with SCSI - for the first time. Two of the 4 drives checked out OK, so now I'm ready to try the HP drives.
If you haven't read Radified's article on SCSI, it might be worth your while. It got me interested. Even if you don't have the IBM (mine don't say IBM but the DDYS model led me to IBM) you might find it worthwhile to download IBM's Installation and Reference Manual for the IBM Ulstrastar 36LP for the very good information on setting up an Adaptec SCSI card with the drives. You may already be familiar with all of this. Did your server have a PCI SCSI card? Mine did, fortunately.
What size drives do you have? Mine are 2ea. 9.1GB HP/IBM Ultrastar, and 2 ea HP/Hitachi 9.1s. 10,000 rpm, 160 MB/S LVD. Do you know if these are setup for Raid? I'd prefer not, as my intention is to use one for boot, as Rad did, & one for apps. Haven't really planned beyond boot and apps yet.
I wasn't able to discover how to start up the server P.S. once the mobo was gone, and no longer care - as I'll be using a 380W PC supply, at least until I know what size is needed. I'd like to use the supply in my PC, but the connection hassle is probably not worth it. The size of the drive bay pretty well dictates an outboard arrangement anyway.
Glad you found my query. Lets keep in touch, for awhile, anyway. We may be of some use to each other.
The ATX P.S. cabled to the SCSI cage works. The Adaptec card utility finds all drives. Mine have ID# 10, 11, 12, 13. No jumpers on the disks, so the back plane must be setting ID#s. Do you know how to revise them to 0, 1, 2, 3 ? FDISK finds all and can partition them. When formatted and SYSed, the first drive will boot. XP installed much quicker, started quicker, and defrags much quicker.
Tried NTFS but couldn't SYS. Error message said "Can't sys a network drive" so used FAT32, and booted OK.
Mine had a lot of dust blocking good air flow, so I strongly suggest removing the drives from their trays, then vacuuming the drive and blowing out the tray intakes.
XP uses 3GB, including 2GB for the paging file, which will be moved to another drive when all is settled. 5.4GB free now. Remember when 1GB drives first appeared and everyone said "We'll never be able to use it all."