Occasional PC video failures may be due to system overheating and may be rectified by added robust exhaust fans. An assumption that it was the power supply, which had previously resolved the matter, wasn’t the cause for my most recent errant PC condition. Note that if swapping over power supplies, only use the power cables supplied with the new supply. Otherwise you can fry hard drives! 
Also covered is how to simply get system uptime and a recommendation for PC Health (CPU temperatures, fans etc) is given.


Yesterday it got to 420C here in Melbourne Australia before a cool change arrived later in the day. My desktop PC ran throughout the day  in a closed external room with little insulation and no air flow. The room temperature would have been well in excess of the external ambient temperature. When I discovered that the PC was running (unintentionally) last night, it had been up for one day and four hours! Smile  Finally a good outcome!


My desktop PC is an I7 system, circa 2012, on a GigaByte Z77X-D3H mainboard, with 16G RAM, SSD system drive and a number of hard drives. Two hard drives are mirrored and are the repository of user data. Video is a The power supply was a Thermaltake 750W system. I had previously returned a power supply a few years ago, under warrantee when the system became errant. The failure as indicated by the video becoming a colour display on only a few pixels on the left, and sometimes progressing to the the whole screen flickering in colour. A shutdown and restart was required to restore the system operation It wasn’t just a video failure as other functionality stops with the failure such as audio playback. Sometimes the system would eventually shutdown as part of the errant sequence.


When the above fault arose a few a years a go, replacement of the power supply solved the problem. A month or so ago the problem arose again. A search on the issue this time suggested the same remedy This time I elected to do the same but change the power supply manufacturer and upgrade to 1000 ,; and possible seek a replacement of the “errant” supply under warrantee. So I purchased a Cosair 1000 W power supply, and my problems mushroomed!


Both of the Themaltake and Corsair power supplies are modular with respect to the hard drive power connectors. You plug one end of the the SATA power cables into the power supply and the SATA 15 pin Power Connector  (ATX v2.2) into the SATA hard drive. (Additionally, the Corsair ATX cable is modular as well).

WP_20180107_14_37_19_Rich WP_20180107_14_39_06_Rich
The Modular Power Supply SATA sockets.

My catastrophic problem was that although the (SATA) hard drive end of the hard drive power cables is standardised, the other end isn’t.! The supplied cables’ with both the Themaltake and Corsair supplies “looked” the same. A bad assumption! Sad smile!

WP_20180107_14_42_15_Rich WP_20180107_14_42_41_Rich

The supply connectors looked the same but on close inspection, they have different active pins.



In swapping over the power supplies, I assumed that I could just disconnect the cables to the Themaltake supply, remove it,leave the power cables as connected to the drives in place, insert to the new supply and connect the existing drive power cables to the new power supply. The system did not boot. I tried a few combinations including using the old supply, using the new cables, connecting some older SATA drives (not part of the system) outside of the PC. Upshot was I saw some drives fried!! Lightning When I used the new cables things started to work but not with the drives from the system except one of the mirrored drives. Thumbs down



I had to rebuild the system (including installation) using only the new drive power cables with a new system SSD and two new 2T SATA drives (for mirroring). I had fried one 512G SSD and 6 SATA hard drives, costing in excess of $1200.  I lost most of my system data and had also fried my backup drives. Thankfully most of my app projects are in repositories in the cloud. After a few days, I got that errant system crash again! Sad smile So the question remained as to what was the cause of the system failure.



I decided that maybe heat is the problem; maybe the CPU or RAM or other components are overheating. So I elected to get a more powerful case fan and add a second one. I could also add greater cooling directly to the CPU by using liquid cooling as used by overclockers but hopefully this is overkill. My PC case has a fan in the front blowing on the hard drives and an exhaust fan at the top. I decided to beef up the top exhaust fan and add an additional exhaust fan at the rear- top of the case. Both would enable significant airflow increase over the CPU, memory and mainboard. There are two types of PC fans, those that suck and those that blow; those that draw air in those that expel it. The fans are differentiated by their air pressure and air flow. The hallmark of draw fan is its air pressure with its ability to force air through narrow regions; eg hard disk areas.  Upon inspection. the hard disks weren’t running hot so the existing front fan was left untouched. The key aspect of a an exhaust fan is its air flow; the rate at which it can expel air. So I needed two new exhaust fans. I also considered an underside fan that would blow air under the mainboard in the vicinity of the CPU but this was not necessary.


These fans come with optional LED light fantastic displays, which did not interest me so wasn't a discriminating issue when selecting the fans.


Before inserting the new fans I tested them (specifically determining the direction of airflow) and made sure I was inserting them in exhaust mode. When powered up the fans make quite a bit of noise due to air movement, but touch wood, I haven’t had and system issue, as above, since installing these  fans. This includes the sauna conditions that would have existed in the room yesterday. … 28 hours of up time throughout. I had put the PC in sleep mode the day before but it had auto resumed for some reason a hours or so later, which I only realised after the heat of the day had passed. Smile

Hint: Getting System Uptime:

I was able to get he uptime through Task Manager. On Performance tab, when CPU is selected, the Uptime is shown:



Monitoring System Temperatures and Fans

Whilst in the Mainboard’s BIOS software I could monitor the system’s various temperatures and fan speeds. I was able to set some alarms in the BIOS setup so I set the temperatures to 600C. What I needed though was software that could do this while the operating system was running. There was such software that cam with the mainboard but I couldn’t use it with Windows 10, as it was over 4 years old. I tries a few downloadable monitoring software but could not get them to work. Open Hardware Monitor was then recommended to me and I found this simple to install and works well with live detailed system information.


A Sample of the live information from the monitoring software
Nb: Fans 3 and 4 are the new ones.


The monitoring software is able to log the information to a http port as a web page.  I was able to remotely monitor my system using my phone! Smile


Only one conclusion, which is obvious now (in hindsight):
When changing power supplies don’t assume anything! Use the supplied cables with the new power supply. Do not reuse any of the previous ones.