Question Pc won’t start with hdd connected

Dec 23, 2019
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Have a problem with my HP 8300 elite sff computer. It wont start up with sata power connected to any harddrive. If nothing is connected to the sata power the computer starts so i can oad bios settings. If a harddrive is connected all that happens when pushing start buttons is that the fans starts spinning for a second, and then shut of. After a few seconds they start again for a second and shuts off. On and on that goes on.

I would like help to figure out if its the motherboard, psu or anything else is causing this.

Detective work so far:
⁃ all harddrives has been tested on another machine, they all work
⁃ Ive tried different hdds and ssds with different os versions
⁃ Ive tried both sata power outlets and all sata data outlets. And different cables.
⁃ i measured psu voltage rails with dmm. And I have all the rails listed on chassi.(think it was 2x +12v, -12v, 0v). I got the right voltage reading on dmm.
⁃ Tried loading os hdd and ssd connected with sata-usb adapter and plugged to a usb 3 port. Os starts until Windows logo, it loads for a while but the computer shuts off and begin new start up.
⁃ I found what lookes like a regulator on the MB that looks like its been replaced before ( bought the computer second hand). Solder work look different from other components of same style on the MB. See pictures here: View: https://imgur.com/gallery/wHeaHqM
 
Dec 23, 2019
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Maybe you are having a faulty PSU.

Did you try measuring the Voltage manually on 12V rail after connecting it to a HDD and power on?
I did, 12V rails boosts from almost 0v up to 10,5 in that same second the fans spins. But goes down to 0v again as the fans stops and computer restarts. Same cycle as the fans. Pn and on.
When disconnecting harddrive the 12v rail i stable.
 
Jun 29, 2019
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Yeah, that's problem with electronics, it's almost never just one thing.
Check your power supply first, it might be frying your components by the time this thread is posted. If you have a spare PSU, you should try it if the problem persists before concluding anything. You can also try it the other way around by moving the said PSU to another computer. If the problem was carried to that PC then you know the issue here.

That's the only way to confirm that aside from a multimeter. Clip testing do not really confirm anything unless it is dead or died out while trying.
 
Reactions: Sukka
Nov 3, 2019
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Check your power supply first, it might be frying your components by the time this thread is posted. If you have a spare PSU, you should try it if the problem persists before concluding anything. You can also try it the other way around by moving the said PSU to another computer. If the problem was carried to that PC then you know the issue here.

That's the only way to confirm that aside from a multimeter. Clip testing do not really confirm anything unless it is dead or died out while trying.
My personal experiences for similar OP's problems I've had (and have fixed/found problem):

a) I've had faulty measurement of heat sensor in graphics card, I think it was CPU-Z program that recorded it (just for 1/10th of second or less), luckily I had that installed and had a way to check it. Anyhow-fix was to disable safety turn-off in BIOS for overheat (there's also same switch for processor, haven't had to use that). At the moment I have this thing, so no reboot now since "overheat" turned off no more reboots (I got to windows 10 screen, when typing password -> autoreboot). Fixed. Before I had "save temperature to file in usb" random reboots though, so not exactly your problem. I tried GPU overclocking program and it "kind of" worked when I down-clocked it but kept voltage up. But BIOS "ignore heat in GPU" worked fine, asus mobo.

b) Absolutely, another PSU, or what I did was go to friend's place and connected some hardware of mine to his PSU and some to mine-PSU was not providing current (enough voltage of course) so PSU replacement fixed it. You could of course totally disconnect everything from your machine, but GPU and one HDD was enough (mobo had power from my own PSU). NOTE: I have no idea if this is good idea, using two PSU's so wait for someone who really knows or risk possible power leakage if your PSU peaks too much power somewhere, might ground to other machine and - ouch!

c) If no other PSU available, (I've had reverse problem from my quote'd, when power demand grows the current isn't enough and reboot)- so try to launch with, say, linux from USB with nothing else connected, maybe if you have some very low wattage graphics card try with that. Not sure how much USB startup takes though, but it's easy to load at friend's and carry the stick so no harm testing, eh ?
EDIT: ready-bootable linux'es from usb are fast to load and they don't need anything but that usb, just know where you load your executable from (or burn a dvd if you wish but that'l take more power and take a lot longer to do I imagine). Also, if I understood correctly you've tried to start it with only one (lowest power using) HDD in different places- I'd bet a lot it's PSU.

Keep us posted please !
 
Last edited:

Nuwan Fernando

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Jul 26, 2013
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In that case your PSU is faulty since it can't handle the load from a HDD with the rest of your hardware.

Time to replace it.

My personal experiences for similar OP's problems I've had (and have fixed/found problem):

a) I've had faulty measurement of heat sensor in graphics card, I think it was CPU-Z program that recorded it (just for 1/10th of second or less), luckily I had that installed and had a way to check it. Anyhow-fix was to disable safety turn-off in BIOS for overheat (there's also same switch for processor, haven't had to use that). At the moment I have this thing, so no reboot now since "overheat" turned off no more reboots (I got to windows 10 screen, when typing password -> autoreboot). Fixed. Before I had "save temperature to file in usb" random reboots though, so not exactly your problem. I tried GPU overclocking program and it "kind of" worked when I down-clocked it but kept voltage up. But BIOS "ignore heat in GPU" worked fine, asus mobo.

b) Absolutely, another PSU, or what I did was go to friend's place and connected some hardware of mine to his PSU and some to mine-PSU was not providing current (enough voltage of course) so PSU replacement fixed it. You could of course totally disconnect everything from your machine, but GPU and one HDD was enough (mobo had power from my own PSU). NOTE: I have no idea if this is good idea, using two PSU's so wait for someone who really knows or risk possible power leakage if your PSU peaks too much power somewhere, might ground to other machine and - ouch!

c) If no other PSU available, (I've had reverse problem from my quote'd, when power demand grows the current isn't enough and reboot)- so try to launch with, say, linux from USB with nothing else connected, maybe if you have some very low wattage graphics card try with that. Not sure how much USB startup takes though, but it's easy to load at friend's and carry the stick so no harm testing, eh ?
EDIT: ready-bootable linux'es from usb are fast to load and they don't need anything but that usb, just know where you load your executable from (or burn a dvd if you wish but that'l take more power and take a lot longer to do I imagine). Also, if I understood correctly you've tried to start it with only one (lowest power using) HDD in different places- I'd bet a lot it's PSU.

Keep us posted please !
Since it boots fine without the HDD, it's hard to pin point to a faulty sensor.
 
Dec 23, 2019
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10
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In that case your PSU is faulty since it can't handle the load from a HDD with the rest of your hardware.

Time to replace it.
Thanks everyone for taking the time!

I have not connected the hdd power from an external pc, but the sata data cable to the faulty Pc. Now the faulty pc starts correctly. I measure 12v, 5 v and 2x 0v at 4 pin sata power outlets on the MB.

Dont know what this tells me yet. Can try to connect some usb usb devices etc to see if the psu can handle the current?
 
Dec 23, 2019
6
0
10
0
Check your power supply first, it might be frying your components by the time this thread is posted. If you have a spare PSU, you should try it if the problem persists before concluding anything. You can also try it the other way around by moving the said PSU to another computer. If the problem was carried to that PC then you know the issue here.

That's the only way to confirm that aside from a multimeter. Clip testing do not really confirm anything unless it is dead or died out while trying.
i found a psu from an older pc, but the connectors are all different. see pics: Psu

Dont know where to go with this, if there’s any adapters for example
 
Jun 29, 2019
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Thanks everyone for taking the time!

I have not connected the hdd power from an external pc, but the sata data cable to the faulty Pc. Now the faulty pc starts correctly. I measure 12v, 5 v and 2x 0v at 4 pin sata power outlets on the MB.

Dont know what this tells me yet. Can try to connect some usb usb devices etc to see if the psu can handle the current?
I don't know why you should be doing this but it really doesn't matter if you connected it or not (especially if the PSU is the problem). One thing for sure is that you can check the HDD if it's working or not by connecting it to a new device and scanning it for bad sectors and similar stuff (like chkdsk). You might also want to check the sata and power cables if it's faulty or loose.
If you have multiple HDD, you should try it one by one. One of them might be failing or has bad sectors, etc. But if my guess is right, even though you fixed these issues, it will come back and bother you over and over again.

It's a lesson learned the hard way.
 
Last edited:
Dec 23, 2019
6
0
10
0
I don't know why you should be doing this but it really doesn't matter if you connected it or not (especially if the PSU is the problem). One thing for sure is that you can check the HDD if it's working or not by connecting it to a new device and scanning it for bad sectors and similar stuff (like chkdsk). You might also want to check the sata and power cables if it's faulty or loose.
If you have multiple HDD, you should try it one by one. One of them might be failing or has bad sectors, etc. But if my guess is right, even though you fixed these issues, it will come back and bother you over and over again.

It's a lesson learned the hard way.
sorry, I meant NOW not NOT. I gave the OS SSD power (not data) from another computer and I could start my faulty PC.

I will probably order both a motherboard and PSU from eBay. Both will cost about €70 incl shipping, so..
 
Jun 29, 2019
185
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sorry, I meant NOW not NOT. I gave the OS SSD power (not data) from another computer and I could start my faulty PC.

I will probably order both a motherboard and PSU from eBay. Both will cost about €70 incl shipping, so..
Probably the best idea. Your board looks like a fried fish you might want to get a new one.

Oh and about ebay, don't order a 2nd hand PSU. Never ever do that unless you want to test your Pc's fire resistance.

I like buying 2nd hand items in the past. Well the PSU blew, and bought a 2nd hand replacement and it was also failing and is about to fry my Pc tripping the board's anti surge protection.
 
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