MS-6390: Return Of The USB Problem!

Question

Almost a year ago I posted a thread regarding a USB problem  in which after a few hours runtime, the USB ports stop  working. Having reinstalled Windows, I followed the  original thread to fix the problem again but this time, it  hasn't work. The old thread for reference is; https://forum-en.msi.com/index.php?topic=49727.0
but I shall try and include everything important here so it  shouldn't be needed.
Firstly the nature of the problem;
Any new device plugged into them is not recognisied and  Windows advises that it is the device that is  malfunctioning.
Restarting the computer will eliminate the problem, however  upon rebooting, the computer tends to get stuck at what may  be the memory count. If left for 10 minutes, the memory  amount comes up and the computer boots normally. This is  circumvented by temporarily (one second) removing power to  the power supply by pulling the plug or flicking the switch  at the back.
[It may or may not be relevant that the HDD activity  indicator is lit for approximately 30 seconds of this 10  minute period]
Upon switching the computer on again, the computer boots up  normally and the USB ports continue to function for another  variable period of time.
This problem occurs if there are no devices plugged into  the USB, any single device (printer, gamepad, mobile phone)  or any combination.
It should also be noted that if the computer crashes due to  any of many unrelated reasons after this problem has  arisen, and I use the reset button to make it reboot, the  10 minute reboot problem occurs again but appears  differently on screen in that it actually says 'memory  check' or words to that effect with a space where the  normally RAM amount goes, a  '+'  and another empty space  where the memory reserved for onboard graphics normally  goes (i.e. memory check:       +     )
I've tried uninstalling the drivers and reinstalling those  downloaded from VIAs website for my chipset.
My USB ports are set not to power down to save power in  device manager.
The multi-card reader (plugged directly into the  motherboard) also stops functioning when the USB ports go  down - power light stays on, activity light stops flashing  (occasionally power light turns off). Unplugging it from  the motherboard does not resolve the issue.
I want to resolve this issue so the computer is trouble-free when I give it my mum to learn from.
Comp. specs in signature. Thanks in advance.

Answer 1

I don't know how to dig deeper...  Soon this computer will only be using a single 80 gig HD, and I'll remove the fan controller (it'll be mums computer). I'll then be able to try just using sp1a.
This PSU I'm using is reviewed here with a several others. (the model number is the same, but the one tested doesn't appear to be dual rail - they actually state the number slightly incorrectly, but it's correct in the picture of the label they show.
I think it performed quite well, being one of only two that were able to keep producing (just) over 1 v at 100% load, whilst most others just plumetted. A significant but probably not damaging drop to 4.87v on the 5v rail and again 3.26 on the 3.3v rail all at 100% load (which you're never supposed to due to the PSU anyway). It got a recommended award since apparently it doesn't have many features but I don't think I'm in need of any features it lacks.
Furthermore - at the back it has a control for fan speed. Currently set on Auto, it maintains the same fan speeds (audiability) as on Low - thus I conclude it has headroom to push itself if necessary (in which case the fans would spin faster).
Apart from someone who said they're "cheapo", I havn't yet found any negative comments regarding Jeantech PSUs.