When I turn on my HP 6300 Pro SFF, the PSU fan goes balls to the wall and no post or anything on screen. When I disconnect it from mobo and jump the green and black pins on P2 connector it does the same thing. Could the PSU have a bad capacitor or capacitors? Or maybe another board component that I could replace to get it to calm down and allow my PC to boot?
CPU HP 6300 PRO SFF Power supply fan spins at 100% and won't boot.
- Thread starter Apache23
- Start date
Do you have a spare power supply to check the rest of the system with?
Edit: seems that may be harder to do than I thought... HP and their weird PSU BS.. https://www.ebay.com/itm/322484391965
You may have to try reseating all the cards and memory, but usually the board should throw a beep code to alert to those :/
Edit: seems that may be harder to do than I thought... HP and their weird PSU BS.. https://www.ebay.com/itm/322484391965
You may have to try reseating all the cards and memory, but usually the board should throw a beep code to alert to those :/
Thanks for the reply. I was in a hurry yesterday when I posted this, so I didn't add much info. Everything except 2 sticks of RAM and the SSD have been removed. The PSU spins crazy even unhooked from the computer, using jumper to power it on. So I was wondering if there was a signal wire or something that when hooked up to the mobo would make the fan calm down. Kinda like when you use an ATX PSU with a 24-6 pin adapter, the CPU fan spins out of control unless a jumper is used from the fan connector. But I'm guessing it's the PSU that's bad.
@Apache23 merged threads 
I think the full speed fan mode is normal when the board hasn't started booting (or no board detected).
If you have a standard power supply around you may be able to use an adapter like this to test the board. Just to verify, you've tried reseating that weird white 6 pin inline connector? Seems the power_on and power_ok signals go through that.
Looks like, from some googlin' that the power wires are standard ATX colours
I think the full speed fan mode is normal when the board hasn't started booting (or no board detected).
If you have a standard power supply around you may be able to use an adapter like this to test the board. Just to verify, you've tried reseating that weird white 6 pin inline connector? Seems the power_on and power_ok signals go through that.
Looks like, from some googlin' that the power wires are standard ATX colours
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@Apache23 merged threads
I think the full speed fan mode is normal when the board hasn't started booting (or no board detected).
If you have a standard power supply around you may be able to use an adapter like this to test the board. Just to verify, you've tried reseating that weird white 6 pin inline connector? Seems the power_on and power_ok signals go through that.
Looks like, from some googlin' that the power wires are standard ATX colours
Actually that was my original plan, hooking up a regular PSU to it. I have an EVGA 500w PSU that I've been trying to use. I have had that 6-pin connector hooked up in about every configuration I can find and no go, so I was just gonna keep using the original one. That's when it started doing the full speed thing. I think one of my problems is that you need an adapter like the one you linked to change the purple 5v wire on the other 6-pin plug, to 12v. So are you thinking the PSU is supposed to run full speed and maybe there is a wire I don't have hooked up right that would calm it down? Also, I didn't take a pic of the 6-pin P2 connector before I started changing wires around and now I can't seem to find the original configuration. I've looked at used PSU's for 6300 Pro SFF's online, but every one I've looked at, you can't see the wires good enough to tell where they go! That's frustrating too!...lol. Because I know the 6300 Pro SFF wires are in a different config than the others, so I can't use their configs. I have a green, grey, black, white and white-w-red stripe that need to be put in the right places. Thanks for the reply.
The only real way to test any power supply is to use a ohm/voltmeter, and check each wire's voltage output. Since You want to use an Atx or derivative from that form factor you will have to use the adapter cable setup suggested and then determine which wires from the normal Atx pinout (green wire usually) are funneled through the adapter cable to the white connector. on the MB. Once you know which wire on your original PS is powered on then you can run to ground and test output voltages. The usual problem for these cheap junk power supplies That are used by ALL OEMs to save and make a profit when only the fans turn on, and there is no bootup process, is the power-good circuit is gone bad. (All quality PS's for boards must deliver power to the CPU within a time interval or the CPU will not BOOT!)
The ATX specification defines the Power-Good signal as a +5-volt (V) signal generated in the power supply when it has passed its internal self-tests and the outputs have stabilized. This normally takes between 0.1 and 0.5 seconds after the power supply is switched on. The signal is then sent to the motherboard, where it is received by the processor timer chip that controls the reset line to the processor.
The ATX specification requires that the power-good signal ("PWR_OK") go high no sooner than 100 ms after the power rails have stabilized, and remain high for 16 ms after loss of AC power, and fall (to less than 0.4 V) at least 1 ms before the power rails fall out of specification (to 95% of their nominal value).
Cheaper and/or lower quality power supplies do not follow the ATX specification of a separate monitoring circuit; they instead wire the power good output to one of the 5 V lines. This means the processor will never reset given bad power unless the 5 V line drops low enough to turn off the trigger, which could be too low for proper operation.
Most likely this is what HP engineers/ and motherboard suppliers, sicn HP does make any of their boards have done this with your 6300. If the power-good circuit is not the problem then the board or a component on it is not performing or is deceased. Since your board has no speaker pinout to test failure beeps you only option would be a board tester like this:
Tester
The ATX specification defines the Power-Good signal as a +5-volt (V) signal generated in the power supply when it has passed its internal self-tests and the outputs have stabilized. This normally takes between 0.1 and 0.5 seconds after the power supply is switched on. The signal is then sent to the motherboard, where it is received by the processor timer chip that controls the reset line to the processor.
The ATX specification requires that the power-good signal ("PWR_OK") go high no sooner than 100 ms after the power rails have stabilized, and remain high for 16 ms after loss of AC power, and fall (to less than 0.4 V) at least 1 ms before the power rails fall out of specification (to 95% of their nominal value).
Cheaper and/or lower quality power supplies do not follow the ATX specification of a separate monitoring circuit; they instead wire the power good output to one of the 5 V lines. This means the processor will never reset given bad power unless the 5 V line drops low enough to turn off the trigger, which could be too low for proper operation.
Most likely this is what HP engineers/ and motherboard suppliers, sicn HP does make any of their boards have done this with your 6300. If the power-good circuit is not the problem then the board or a component on it is not performing or is deceased. Since your board has no speaker pinout to test failure beeps you only option would be a board tester like this:
Tester
Thanks, that was some amazing info! The original PSU has 5 wires going to that 6-pin P2 connector. A grey one, which is "power good", a green one which is "ps on", a black common and 2 white wires, which I think are fan related? I'm having no luck at all finding the original config of the wires in this P2 connector. I'm almost positive that the green and grey go on the 2 middle pins (3 and 4), but not sure which goes where. Then I think the black one goes on 1 or 6 and the white go in the 2 outer spots opposite the black. And it actually does have a speaker connection, I just found it. So I'm going to see if I can find one and then see what beeps I get. Thanks again and I'll post my results if any.
Well, the only speaker I could find is one of those Dell Optiplex 4-wire powered (I think) speakers. I tried just hooking up the red and black wires, but no beeps. I did some voltage testing on the wires and on the bigger 6-pin connector, I got the correct voltages on the yellow wires (12v), but on the purple wire I got 11.3v nd on the blue wire I got 11.83v. I thought the purple wire was supposed to be 5v standby that kicks up to 12v. It stays at 11.3v as long as the PSU is plugged in to the wall and when unplugged, the voltage drops slowly to 0. So I hooked up my EVGA 500w PSU (removed yellow, purple, black and blue wires from 24-pin connector and spliced them into a 6-pin connector and plugged it into mobo) and I got the same voltages as with the OEM, full speed spinning PSU. I also noticed the chip closest to the two 6-pin connectors is getting very hot pretty quickly. I will post pic and it is the biggest chip in picture tht says NUVOTON on it. Well, never mind. I'm not sure how to upload a pic on here. The chip is about 3/4" x 1/2".
This should help with pinouts: LTT PINOUT DISCUSSION
This is the best adapter: MODDYI ADAPTER
the Nuvoton is probably the Northbridge/or Southbridge. chipset controlling multiple items and should get hotter depending on the number of items it is controlling. (this could be Sata, USB, PCIE, ram etc)
This is the best adapter: MODDYI ADAPTER
the Nuvoton is probably the Northbridge/or Southbridge. chipset controlling multiple items and should get hotter depending on the number of items it is controlling. (this could be Sata, USB, PCIE, ram etc)
Do not see a resolve here. I have the exact same issue notably the bios does signal no ram state when all removed so it does appear the POST is finding an issue... I suspect CMOS having drained mine and replacing the battery. Garbage day is in a week and a half!
