I have a Compaq Evo W8000 and I need the voltage readings for the connections from the power supply to the system board. I suspect the green lead as all other voltages match the outputs listed on the power supply. The voltage on the green lead from the power supply is 2.43 volts. I just need to know what it should be. Thank You Jim

Compaq Evo W8000; Power supply Service manual here: http://h20000.www2.hp.com/bc/docs/support/UCR/SupportManual/TPM_229690-001/TPM_229690-001.pdf Hardware reference guide here. http://h20000.www2.hp.com/bizsupport/TechSupport/CoreRedirect.jsp?redirectReason=DocIndexPDF&prodSeriesId=322279&targetPage=http%3A%2F%2Fh20000.www2.hp.com%2Fbc%2Fdocs%2Fsupport%2FUCR%2FSupportManual%2FTPM_221474_rev002_us_via%2FTPM_221474_rev002_us_via.pdf Neither mention anything special about the power supply, or list its pinouts and voltages, because it is not special - you DO NOT have a proprietary PS - you can use any standard PS with either or both of a 22 or 24 position main power connector. Originally it is rated at 5xx watts capacity, but if you have to replace it a 4xx watt one is probably fine unless you computer is extremely loaded - just don't buy an el-cheapo. The wiring at the main power connector is standard. Green in the ATX PS main connector is standard for ATX PS's and is the "p_on" wire. It is a signal wire that tells the PS to fully turn on if the proper voltage is detected (after you press the power switch - or short the pins for the switch briefly on the mboard). On an ATX mboard it does not supply voltage, it reads the mboard voltage where it is connected - the voltage there is "processed" through the mboard from other circuits that are always on, also from the PS, and the wire senses the end result of what the mboard does to that voltage. It is supposed to SENSE 3.3 volts or thereabouts. More info here - see Soft Power On: http://www.pcguide.com/ref/power/sup/funcSoftPower-c.html See ATX/NLX http://www.pcguide.com/ref/power/sup/funcAdditional-c.html The PS must be connected to that connector for it on the mboard, and it must have a good connection - sometimes you may have to unplug, plug in again the main connector from the PS to the mboard if the connection is poor. Make sure the wires that go to connector are not sharly bent just before the the connector plugs into the mboard, and the individual wire are locked - that is they do not move out of the connector when your plug the connector into the mboard. If there is something seriously wrong with your mboard or anything connected to it, the p_on wire voltage may be improper for what the circuit inside the PS wants, and the PS will not fully turn on. If your mboard will not boot, try this PS with another working computer! The computer you have it connected may be the problem, not the PS! If it doesn't work with the other computer it is definately fried! Many other things can cause a no boot condition. If you have made no hardware changes: 1. Flashing your bios using the wrong bios update, or something going wrong during a flash, or the flash chip physically failing while flashing can cause your mboard to NOT BOOT after the bios is flashed!! 2. A bad PS, but you need to test for other possibilities before you conclude that, unless it stinks of burnt wiring, or the fan has stopped spinning even when the PS is tested on another computer. If you have made hardware changes: 1. A very common one is incompatible ram. If you have just added a ram module you haven't used in this motherboard before, and its size is not properly recognized or the computer will not boot with it in, the problem is almost always you are trying to use a ram module that is incompatible with the mboard - there is nothing wrong with the ram, and nothing wrong with the mboard - they jusy can't be used together. 2. If you changed the cpu it must be compatible with the motherboard AND the bios version you have - if the bios does not recognize it, the mboard often will not boot in many cases.

What I said about testing the PS in another computer, and the other causes of no boot, still applies, but...... Waddaminit. 22 pin power connector? And I've made some other assumptions that may not hold up. I found a manual I have for a fairly recent Enermax series of standard PS's. 20 pin ATX power connector, two types of 24 pin ATX power connector that have identical connectors but definately are wired differently, but no 22 pin one. green is p_on on all - 20pin and both 24 pin. 3.3 volt Sense is orange and a smaller brown at the same location (pin)- - on 20 pin , at pin 11 on the end, 3rd position away from green, on the same side of the connector - on the first 24 pin, at pin 13 on the end, 3rd position away from green, in the same relative locations - the wiring is identical locations (but not the pin numbers after 10) to the 20 except 4 more wires at the 12/24 pins end The above two are the only connector types I've seen on what I've purchased. The second 24 pin is labelled AMD ATX-GES, has no 3.3 volt sense wires, the p_on wire is on the other side of the connector, and most if not all the wiring is different from the other two. I'll have to check this out further.

I'm back! Green wire is P_ON or PS_ON or Power On in all the main PS connectors I've looked at - they all seem to be the same thing in ATX and up PS's. The voltage is not specified on the connectors - they appear to rely on a circuit within the PS, and input from sense inputs, to determine whether that connection is turned on and the motherboard receives full PS power. This is typical of what I found in Specifications documents: ATX12V version 2.2 (24pin) - PWR_OK, PS_ON (same as P_ON) explained starting page 26 of pdf - connector appearance, pinouts, wirecolors page 36, 37 of pdf..... - 3.3volt Sense is called default sense in this - page 13 of pdf, also shown in connector pinouts, page 37 of pdf http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf Therefore, I can't tell you what the voltage should be. ...... Whether or not you can test your mboard in another computer depends on which PS form factor it's connector(s) is (are). If it is proprietary, it is unlikely you can test it in another, unless you have two or more of these. Since COMPAQ EVO W8000 series are apparently servers, your PS may or may not be proprietary. - If you have BOTH a 24 pin and a 20 pin main connector, the green wire in the 20 pin one, you have an oddball wired proprietary WTX connected PS, meant only for servers. - If you have a single 24 pin main connector only on the PS, you could have one of two standard PS connector wirings. - If you have a Intel cpu, there is probably only one possible standard main connector wiring. See ATX12V version 2.2 specs above. Wiring, wirecolors on connectors - does not show actual shape of other than AT connectors. WTX 24 pin AND 22pin (both are used) - for Workstations - - wiring is different from everything else - only 16 positions actually used on the 20 pin, so 40 connections total. Green is Power On (same as P_ON, PS_ON), also has 3.3v sense, 3.3v sense return, 5v sense, 5v sense return, Power good. http://www.pcguide.com/ref/power/sup/parts_Motherboard.htm If you have an Athlon cpu, it may have a connector the same as in ATX12V version 2.2 specs above, or an ATX-GES connector that is used only on servers. Information (AMD) ATX-GES including connector pinouts page 9 of pdf (24 pin main connector): http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/25823.pdf Wirecolors - same as for ATX12V. See ATX12V version 2.2 specs above. SFX - version 3.1 Main connector wiring - same as ATX12V except no connection pin 20 (-5 volts on ATX12V) - information. SFX specs (24 pin) - connector appearance, pinouts, wirecolors page 36, 37 of pdf http://www.formfactors.org/developer/specs/SFX12V_PSDGr3_%201%20public_br.pdf There are several PS form factors that have exactly the same main connector wiring, but there are differences in the wiring for other connectors from the PS. ATX12V ATX12V version 2.0, released in Feb 2003, requires SATA connectors. ATX12V version 2.1 http://www.formfactors.org/devlist.asp?FFID=1&CatID=2 ATX12V version 2.2 http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf (same as above) ATX EPS 12v - for server and workstation. This specifies a 24-pin main connector and an 8-pin +12v connector for the motherboard. TFX12V (Thin Form factor with 12 volt) -long, narrow enclosure to fit in low profile, microatx, and FlexATX system layouts http://www.formfactors.org/developer/specs/TFX12V%202%201%20PSDG_FINAL.pdf ................................. If your PS is dead, and it is a WTX - 24 pin AND 22pin - you don't have to get it from HP(Compaq). e.g. EPS series PS's (made by SSI) - for servers $99 460watt, $109 550watt http://www.power-on.com/eps12v.html EPS to WTX Adapter price: $12 http://www.power-on.com/connectors-adapters.html Also, if you have an ATXGES (these are probably available from many manufacturers) e.g. ATXGES Server PS's $99 460watt, $109 550watt http://www.power-on.com/atxges.html (same PS's, different wiring to the connectors) ........ HP (and Compaq) parts lists for COMPAQ EVO W8000 here - look up your specific model - a very pokey site if you choose show all parts. You could also look up the part number on your PS - nine numbers like so: xxxxxx-xxx http://partsurfer.hp.com/cgi-bin/spi/main?sel_flg=modsrch&template=main&cpric=&prodsrch=COMPAQ+EVO+W8000&submit.x=11&submit.y=5