The +12 VDC power is +/- 5% which is +11.4 to +12.6 VDC. So it is out of spec.

It's just labeled 12V. Can't remember, but maybe another labeled VDC. I forgot. But I remember for sure, the +12V, that was the label, the thing it's appearently assigned to (in my statement only), is the value it gave. It was about +11.1, hence the ~. Is this understood, and that is what you knew, when saying it's out of spec, right? I'd easily believe it's out of spec, but I still want to hear from you, if you understood what I meant or not. Same syntax, for the +5V, except that was EXACTLY what it said. I know it wasn't up to 11.4 for sure. And it's strange unless something is broke, that the same kind of lead would measure inexact. Maybe the power supply died on both towers? The tower appears, as if it's having the same behavior. Although: I knew before, I think, that main2 had some power outlets that weren't working, from practice. But I never knew that how to label it. So I could have discovered this before, long ago. Except I didn't have the power tool then. I still don't know why the towers seem to have the same behavior though. Unless the hard drive is causing the problem, or they both have dying power supplies. I will try to do the same tests, if this continues to not work this time. It probably won't work, unfortunately.

Although VDC, would usually mean volts direct current. Maybe you just added the DC, for better understanding.

I added the DC out of habit.

The 12 VDC power is used by the spindle motor i.e. the motor that spins the disk's platters.

I've been recapping PC PSUs for 15 years or so without taking any kind of conscious precautions. By the time a PSU is out of the PC unplugged from everything and open, the voltage stored has apparently naturally dissipated sufficiently to eliminate significant risk. It certainly doesn't hurt to simply remove the cover for visual inspection to see if any caps are visibly swollen or have leaked. Any found that way must be replaced to have any chance that the PSU can be satisfactorily used as intended. The one or two biggest ones on one side containing the largest risk are rarely a problem. It's usually the medium sized ones on the opposite side that cause the trouble and visibly leak and/or swell their tops and/or bottoms. http://www.badcaps.net/ has guidance for such repair via its forums, including how and where to buy replacements, and how to select what to buy. The cost of caps to repair a PSU usually amount to less than US$10 not counting shipping, and can be as little as under US$0.50.

That's what I thought for one PC. But maybe I read wrong? Because I expected this second PC to fix it, and well...

Here's some pictures of the hard drives and motherboards, if it will let me. The motherboard pictures are main2, but they have the same motherboard. The hard drive pictures are for the identical hard drives.

They are both: 120 GB Western Digital WD1200JS. By the way, attatchment form not working. Maybe it attatched anyway? Sorry. Took great pictures, but it will not let me attatch. I'm not setting up some website or service or something soly for the purpose of linking files to this post. I could, in theory, if I really needed those pictures, but it's entirely stupid. I'm not going to even link to my google photos or anything. We'll just have to get along without pictures of the motherboard and hard drives. I've tried every way I'm able to to compress them, and they are still too large. Of course, to do that, I had to trick the system into thinking it's a txt file anyway. It's OK, if I really have to, but when it goes this far, where it won't upload, no dice. I'm not going to attempt to break this site either. I do not believe in trying to be destructive with my knowlege, if my knowlege is great enough. Sorry though.

Without loading, PS testers can be misleading. In poorer designs, a 12V rail's voltage can increase as power demands are made for the other voltages by the various devices, particularly the 3V used by the CPU's voltage regulator. 12V sometimes needs to be measured with a plain VOM meter while everything is connected and the PC booted. That said, +11.1V with a tester is suspiciously low.

Western Digital WD1200JS is a 120GB SATA hard drive. It has both the old style 4 pin MOLEX power connector as well as the SATA standard power connector. Does the power supply have both types of connectors?

Both towers I can set up, only have one of modern connector. I guess, I could try to use it in this machine. I'll try a quick power test, to and pay more attention to what it says on this PC.

Like I said, Windows seemed not to care, but maybe the Linux kernel isn't aware of this type of mix??? I could always try to install in compatibility mode, if it might fix some things. I don't know whether it would fix this or not.

Here goes the power test!

Exact copy of output with first power supply adapter in second computer (still running)

Lights:
LCD:
Within spec? And how about how do I read it properly, so I know? I know before, there was a column that said +12V, but now, there is none. Interesting.

This HDD has a jumper to limit its SATA speed from 3.0 GB/s to 1.5 GB/s for compatibility with ancient SATA 1.5 GB/s controllers:
Especially some ancient Via SATA 1.5 GB/s controllers found on mainboards and addon cards don't accept SATA 3.0 GB/s & 6.0 GB/s devices.

A HDD capacity limit given by BIOS isn't relevant for this HDD. These limits are effective for HDD/SSD capacities above 2 TB, in same rare cases above 1 TB.

Don't do extreme JPEG compression, because this is lossy and results in blurry pictures.
Scale down pictures instead. If your camera delivers e.g. 6000×4000 px scale it down to e.g. 20 % = 1200×800 px. Create additional digital zooms of relevant things like mainboard model name.

Post #27 is within spec but as posted this is a no load test.

OK. More information again.

https://www.lifewire.com/test-a-powe...tester-2626160

The video: Finally I understand how to use this thing, according to the video. I guess I was using it wrong. Happens when it's the first real use. On both motherboards, the values look OK to me, according to that. That rules out the problem I thought it was, then. However: clearly the first PC DOES have some power supply issues. It wasn't me, I'm sure. It had them before. The large motherboard plugin appears to be physically falling apart, or not constructed well. As long as I never checked the power supply, it should be fine. But the check (even though I'm sure it wasn't me), makes that's physical condition get worse and worse and worse. Checking was neccessary. I don't regret it.

So, I tried something foolish on second PC. I plugged in one hard drive to the sata power, and the other into the other, since there's not enough power for sata style. I'm learning maybe to use all the newest possible power adapters and bus connectors. Problem now? Well, after that, I plugged them in backwards. Oops! Oh well. Whether it makes a difference or not, it's now backwards and set the same as far as partitions. This was probably the origional order they were in, before I messed with them.

Cool! After that, I got all the way to copying files! However, now it's complaining about srv0 and squashfs blocks not being able to be read. It's not the MBR place though. I'm believing that the DVD is damaged, as my Mom doesn't keep the blank CDs very well. But yesterday, it was all I had! Probably, the ISO may be corrupted too, but not sure. Tell me what you think, but that is what I think.

It may just hang at that step now. Lucky for me, I wondered about that, so redownloading commences now! I prepared by bringing a blank DVD from home.