Recently I decided to build myself a better desktop computer to replace the decidedly cranky old Dell I used to have. I built the thing without
problems, installed Linux Mint, and it's been running for a couple of months. Here's the spec:
Micro ATX Case
Corsair CXM 500W modular PSU
Asus M5A78L-M/USB3 Motherboard
AMD FX8350 8 core processor
Corsair 8GB 1600MHz memory modules (pair)
60GB SATA SSD (Kingston) - primary drive
1TB SATA hard drive (Western Digital) - home area/data storage
This runs really quickly, all temperatures are good and if I don't touch it it's really reliable. Unfortunately, if I walk up and plug
something into a USB socket it goes haywire - if I plug into the sockets on the front panel the computer shuts down. If I plug something into the
back (e.g. I have my smartphone dock permanently plugged into the back, and park my phone when I sit at the desk) the video goes haywire and the only
way out is to reboot the machine.
My guess is that this is due to a static discharge resulting from me walking over the carpet. I haven't heard or felt any discharges, but that
doesn't mean that there wasn't one!
I've checked that everything is OK - plugs, connectors, etc. - and I can't see anything wrong. None of my other kit in the same location is
bothered when I plug into their USB ports (laptop, tablet, and so on).
I don't get a problem if I touch the case before I do anything - but I can't always remember to do that!
Can anyone suggest further tests that might help me to localise this problem?
[Edited on 13/8/13 by David Jenkins]
sounds like the PSU is marginal and when you take more power out via USB it falls over?
try a different PSU first?
I'm only talking about plugging in a memory stick - hardly power-draining! Anyway, the PSU is 500W and the min recommended is 300W, so I'm
nowhere near capacity. I'm also using the motherboard's on-board video, so no power-hungry graphics board.
[Edited on 13/8/13 by David Jenkins]
I would be suprised if it was static discharge that was the cause.
I would have thought the problem lies with the connection between the usb port and the motherboard. Have you checked all the usb ports are in the
correct connections on the motherboard?
Also have you installed the usb drivers fom the installation disk supplied with the motherboard?
quote:
Originally posted by Ajohnston_10
I would be suprised if it was static discharge that was the cause.
I would have thought the problem lies with the connection between the usb port and the motherboard. Have you checked all the usb ports are in the correct connections on the motherboard?
I believe so - but I'll recheck
Also have you installed the usb drivers fom the installation disk supplied with the motherboard?
Tricky - I'm running Linux and the disk is Windows-based! The ports do work in all respects (USB2 and USB3) apart from when I walk up and plug something in - hence my thinking that it was static from the carpet causing the problem. If I've been sitting next to the computer for a while, probably touching it occasionally, then everything works as it should.
Anything left in the logs? (i.e. dmesg)
Is the case properly earthed?
Try earthing the case properly? Does it sit on a desk?
I've never heard of this hapopening before.
You'll have to remind me where the logs are...
(but I suspect that there won't be any - shut-down is near-enough instant.)
I had considered the earthing - so far I've checked the socket and mains lead, and all systems are go there. I'll check that there's a
connection between the mains earth and the case shortly (with the power off, of course! 
).
[Edited on 13/8/13 by David Jenkins]
Definitely check the case is properly grounded, use a multimeter to check for continuity between the chassis and the ground pin on the 13 Amp plug.
The earth is good from the 13A plug to the case... just checked with my multimeter. I thought it would be, but it does no harm to re-check...
Not just the case though, check the motherboard itself is happy. My last motherboard came with plastic standoffs, I replaced them with older metal
fixings.
Does it change if you have the PC plugged in somewhere else? Could it actually be the power socket earth that's at fault?
I have just asked a mate who is sh*t hot with computers and he said it could be something within the registy that is wrong. He said best to wipe the OS and re-install.
quote:
Originally posted by Slimy38
Not just the case though, check the motherboard itself is happy. My last motherboard came with plastic standoffs, I replaced them with older metal fixings.
Does it change if you have the PC plugged in somewhere else? Could it actually be the power socket earth that's at fault?
quote:
Originally posted by Ajohnston_10
I have just asked a mate who is sh*t hot with computers and he said it could be something within the registy that is wrong. He said best to wipe the OS and re-install.
I'm out of ideas then ha.
Don't have a clue what the problem is.
That makes 2 of us!
(Thanks for taking the time though...)
quote:
Originally posted by Slimy38
Not just the case though, check the motherboard itself is happy. My last motherboard came with plastic standoffs, I replaced them with older metal fixings.
I take your point about the capacity of the PSU but if it is a bit flaky then it might still be a problem.
From your posts it is clear that you know what you are doing so a test swap with another PSU will rule it in or out in a few minutes.
get a psu tester and test the psu.
DJ
quote:
Originally posted by David Jenkins
You'll have to remind me where the logs are...
(but I suspect that there won't be any - shut-down is near-enough instant.)
I had considered the earthing - so far I've checked the socket and mains lead, and all systems are go there. I'll check that there's a connection between the mains earth and the case shortly (with the power off, of course!
[Edited on 13/8/13 by David Jenkins]
Just in case it's a drivers/software issue you could load Ubuntu or something on a memory stick/CD and run it from there.
See if same thing happens then.
If it still happens then, you know it's h/w related.
Good luck,
James
quote:
Originally posted by iank
just type dmesg you might get lucky
quote:
Originally posted by James
Just in case it's a drivers/software issue you could load Ubuntu or something on a memory stick/CD and run it from there.
See if same thing happens then.
If it still happens then, you know it's h/w related.
Good luck,
James
Just thought I'd quickly chime in and mention that your case, nor the components require grounding! Hence the reason cases are painted and
components come with plastic feet. This isn't a car and no power or signal goes via a ground. Its all done on the cables. Your PSU has its
earth and thats it. Please don't try to ground your components.
I'd estimate you have a faulty mobo, or faulty drivers. Do you have another distro you can try or even windows?
How do the drivers know he's touched the case before plugging in?
quote:
Originally posted by deezee
Just thought I'd quickly chime in and mention that your case, nor the components require grounding! Hence the reason cases are painted and components come with plastic feet. This isn't a car and no power or signal goes via a ground. Its all done on the cables. Your PSU has its earth and thats it. Please don't try to ground your components.
I'd estimate you have a faulty mobo, or faulty drivers. Do you have another distro you can try or even windows?
mookaloid - I don't have a spare PSU! And I'm not in a rush to spend another £50 to test a theory.
jossey - Although a PSU tester would be good, I think I can get the same info from a system monitor installed on my system. This shows me all the
important voltages used on the motherboard (and they're all good at the moment).
Search on tinternet found people with similar issues :
"Yeah, I've seen this issue myself. It ended up being a lack of a gound from the USB ports. I would recommend checking the front panel USB
board on the case and see if you can solder or connect a cable from the outer USB shield back to the metal framework of the case. Otherwise I suggest
changing the case. "
"I have had a rash of machines recently that have been rebooting when users attempt to use USB drives. All the cases have been Cooler Master
however motherboards have been Asus, Asrock and Gigabyte. I stumbled upon this when I heard a machine reboot. I could actually hear the pop from the
ESD. I then noticed that all machines experiencing the issue has plastic wheels on plastic carpet savers. I decided to do some testing and got an
elite 331 and sure enough I can make it reboot over and over. I grabbed some cat5 took out a pair and solder and covered a small connection to each
USB and then ran the cables over to a screw hole on the front of the case and tested. No more reboots and then I did this to the four machines I had
doing the reboot issue and so far not a single customer complaint.
This is just FYI. I will probably just take to modding each case before I ship them out so I never have to worry about this issue again."
"the nearest I 've had was back in the mid 80's
when static discharge to the control panel on a AMPEX VPR2 vt machine would
switch the machine to ready
we just sprayed the carpets with a antistatic spray"
Have you tried it on another mains circuit? or in a room with no carpet ?
[Edited on 14/8/13 by andyace]
As someone who used to build >10 PCs a day by hand and had to troubleshoot on the fly my initial instinct would be a faulty cable between the
motherboard and ports.
See what happens if you plug your USB devices in via
1. An unpowered USB hub &
2. A USB hub that has it's own power supply.
Do either make any difference ?
(borrow the hubs from friends and neighbours rather than buying them. one thing ive learned is the last thing you want to do when troubleshooting is
throw too much time and money testing each stage)
quote:
Originally posted by David Jenkins
mookaloid - I don't have a spare PSU! And I'm not in a rush to spend another £50 to test a theory.
Hi,
Pretty sure it's nothing to do with static but depending on what peripherals you have connected and what type of power supply they use, you can
see little sparks as you connect devices sometimes. This is often caused by peripherals such as printers or external hard drives having unearthed
power supplies. This causes the shell of the USB port on the cable from these devices to "float" to a voltage roughly around 180 volts.
However, as soon as you plug the device in, it should earth this floating voltage and all should be well. It's why you sometimes get a tingle in
your fingertips when plugging stuff in.
However, you say that it happens even with memory sticks which don't have an external PSU. So might not be that.
The other thing I have had trouble with in the past is with the CRT or LCD monitor. I had one which caused an awful electrical buzz and video
distortion when connected via one video cable but which worked fine with another video cable. This was the 15 pin SVGA cable at the time but the same
thing might happen with DVI or HDMI or whatever you are using.
So, try swapping video cable and/or monitor if you can and try again.
HTH,
Craig.
quote:
Originally posted by David Jenkins
mookaloid - I don't have a spare PSU! And I'm not in a rush to spend another £50 to test a theory.
quote:
Originally posted by Not Anumber
As someone who used to build >10 PCs a day by hand and had to troubleshoot on the fly my initial instinct would be a faulty cable between the motherboard and ports.
See what happens if you plug your USB devices in via
1. An unpowered USB hub &
2. A USB hub that has it's own power supply.
Do either make any difference ?
(borrow the hubs from friends and neighbours rather than buying them. one thing ive learned is the last thing you want to do when troubleshooting is throw too much time and money testing each stage)
quote:
Originally posted by andyace
Search on tinternet found people with similar issues :
"Yeah, I've seen this issue myself. It ended up being a lack of a gound from the USB ports. I would recommend checking the front panel USB board on the case and see if you can solder or connect a cable from the outer USB shield back to the metal framework of the case. Otherwise I suggest changing the case. "
<snip>
I've used my multimeter to check the metal shield around the sockets - there's a zero ohm connection between the shields and the case. There are some aspects of the case I don't like, e.g. if I struggle to get a USB stick out then there's a fair chance that my knuckle will push the off switch (but that's not the cause of this issue!) so I might yet replace it. Rather reluctant because it's new.
Have you tried it on another mains circuit? or in a room with no carpet ?
The trouble is that the failure is so random that I could spend 2 weeks trying to reproduce it, wherever the machine is placed. The same goes for replacing the PSU.
quote:
Originally posted by mookaloid
quote:
Originally posted by David Jenkins
mookaloid - I don't have a spare PSU! And I'm not in a rush to spend another £50 to test a theory.
I have never spent anywhere near that much on a PSU before - maybe that's why I have had a few failed ones!
quote:
Originally posted by David Jenkins
quote:
Originally posted by mookaloid
quote:
Originally posted by David Jenkins
mookaloid - I don't have a spare PSU! And I'm not in a rush to spend another £50 to test a theory.
I have never spent anywhere near that much on a PSU before - maybe that's why I have had a few failed ones!
I've had PSU problems in the past, so I decided that I'd get a decent one! It's modular, so I only use the leads I need which makes the inside of the case really tidy, and it's very quiet (important to me).
quote:
Originally posted by mookaloid
quote:
Originally posted by David Jenkins
quote:
Originally posted by mookaloid
quote:
Originally posted by David Jenkins
mookaloid - I don't have a spare PSU! And I'm not in a rush to spend another £50 to test a theory.
I have never spent anywhere near that much on a PSU before - maybe that's why I have had a few failed ones!
I've had PSU problems in the past, so I decided that I'd get a decent one! It's modular, so I only use the leads I need which makes the inside of the case really tidy, and it's very quiet (important to me).
I'm thinking of building a media pc for the living room at some point so I might invest in a quiet £50 PSU for that.
quote:
Originally posted by jossey
@@@@@@@@ Or buy a raspberry pi n download xbmc it's great.