Actually, after reading your descriptions of the problems you've been having, I'd be willing to bet that yes, your K7AMA does suck.
I've built a few Athlon systems and whatever problems I've encountered have always seemed to have come from the motherboard or the chipset rather than the processor itself. In particular the problems your are describing (dificulty installing a OS, general instability, errors in the registry every time you look) sound an awful lot like a problem with data corruption I encountered when I combined a 1.4gig Athlon with another ECS made motherboard, the K7S5A. While the board you have uses a different chipset than the K7S5A (ALi vs. SiS), the problems I ecountered with the K7S5A were not present in any other manufacturer's versions of boards with that chipset. It was ECS specific problem which came from a change to from the refence design which ECS made and which disapeared when ECS (in later revisions of the board) changed the resistors in question back. Now, as I mentioined earlier, your board has a different chipset than the one I used, so there's no guarantee it's the same problem, but I wouldn't put it past ECS to screw the same thing up twice.
One way to check for this problem is to download and run Memtest86 from
http://www.memtest86.com With the K7S5A the problem appeared in the form of a few thousand errors in parts 3 and 4 of this test. Now it should be noted that this test is actually designed to test memory for errors, not motherboards. But if it is as it was in the case of the K7S5A and you can take the memory out of your computer, install it in another one, and run the test again without any errors, then the problem is probably the motherboard, not the memory. (ECS didn't agree with this logic and later bios versions for the K7S5A prevented the board from running Memtest properly).
One thing that you can try if the test does return errors when run on your computer but not when you run it in another machine withthe same memory, is to underclock your CPU from 133mhz FSB to 100mhz. Becasue the K7AMA lacks the ability to run the CPU and the memory asychronously, when the CPU is underclocked, the RAM is as well. If you can run the test again at the lower speeds with fewer or no errors, you might want to consider reformating your hard drive and reinstalling everything (to get rid of any files that might have been corrupted durring the previous install). You'll then be running your 1400mhz Athlon at a rather pokey but more stable 1040mhz.
To underclock your FSB speed you need to change the JP2A jumper. This jumper is located in the lower right hand quarter of the board near the IDE connectors. It is in a block of three sets of jumpers (with JP2B and 2C) and it's exact location can be found on page 13 of your motherboard's manual. When pins 1 and 2 of this jumper are connected it is running at 133mhs, you will need to switch the connector over to pins 2 and 3 to get 100mhz. One other thing to note, while checking on some other tech support boards I've noted that the most common problem people seem to be having with the K7AMA is the lack of the JP2A jumper. I have no idea why ECS would choose to remove this jumper, but if it is missing on your board, then you can pretty much just disreguard the previous few paragraphs.
While I'm on the topic of jumpers, the K7AMA can use either SDRAM or DDRAM. I'm not sure which kind you are using, but which ever it is, there are jumpers which need to be set for the board to work properly. The J5-J14 jumpers tell the motherboard which kind of ram is being used and which slots to look for it. If these were set improperly, I rather doubt that the board would even post. The JP1 jumper, which is located directly above the memory slots, controls the voltage that the RAM is being run at. For SDRAM pins 1 and 2 should be bridged, for DDRAM pins 1 and 2 should be open. The board might still work with the RAM at the wrong voltage, but it wouldn't be working very well.
In addition to these two things, I have checked a couple different boards (the most useful of which was the ECS board at
http://www.ocworkbench.com you might want to post your problem there and see if they can be more helpful) and have put together a short list of suggestions that have been given for similar problems.
Powersupply- Your Antec 300 should be fine in this department, but whenever anyone mentions a stability problems, the first suggestion always seems to be "upgrade your powersupply". The only thing you need to check here is the sticker on the side of the powersupply. Look for a note about the Total Combined Output of the 3.3v and 5.0v lines. Any TCO over 180w should be sufficient (some would say 230w, just to be safe) and I'm sure your PS shoud have at least that.
Memory- Actually, after the motherboard this would be my most likely suspect. The K7AMA bios doesn't seem to have any way of adjusting memory timings for extra speed or stabilty, so there's really nothing you can tweek there. I also haven't read about any particular problems the ALi chipset has with any specific manufacturer's RAM. I don't know who made your RAM, or even what the specs are on it so I can't say for certain, but it could be that while your RAM might not necessarily be bad, it might not be good enough. The RAM you have might not be capable of running at the default timings (which cannot seem to be adjusted) at the speed your motherboard wants. This could definatly be the case if the problems you experience at a 133mhz FSB go away when you lower it to 100mhz. The best way to check this is to get your hands on some other RAM (I'd borrow some from another one of your computers or a friends before I went out and bought more) and try that. Which ever kind you end up trying make sure that it is rated at least CAS 2.5 (3 is more common, but if the mobo's trying to run it at higher than that, and that can't be changed, CAS 3 RAM could produce errors) and PC133 for SDRAM or PC2100 or DDRAM and check that all the necessary jumpers are set properly.
Heat- The Athlon 1.4 puts out a lot of heat, and your cooling might not be up to the task. While I've seen Athlons running seemingly stable at 70 and even 80c (although I'd never recomend letting them get that high) I've also seen them flake out at just 50c. Another suggestion is that the motherboard's Northbridge might be overheating. The Northbridge is where the memory controlers are and if it gets to hot, data corruption could result. ECS likes to attach their North and Southbridge heatsinks with a substance whose color, texture and (I'm willling to bet) thermal conductivity resemble those of bubblegum. It is suggested that you could remove your motherboard's Northbridge heatsink, scrape off the pink stuff, and reapply it with a good aftermarket thermal adhesive like Artic Alumina Adhesive. It should be noted however, that this will void whatever warrently you still have on the motherboard.
BIOS- A newer bios version for your board might solve the problem, but I rather doubt it. The most recent BIOS is dated 8/12/02 and can be found at
http://www.ecs.com.tw/download/k7ama.html There is also has a link to where you can find the necessary flash utility and a pretty good list of instructions (with pictures) of how to use it. Flashing a mobo BIOS isn't that hard or that risky if you do everything exactly right and your computer doesn't have any problems with stability or data corruption. Unfortunatly your computer does seem to have data corruption issues and most defianatly has stability problems. I'd recomend not trying to flash anything until you're certain these problems have been resolved.
In the end I had to resort to soldering a resistor on to the back of my board to get it working right at 133mhz FSB. In your case, especially since I'm not sure that the resistor trick would work, if nothing else seems to help I'd suggest just getting a new motherboard, preferably one not made by ECS. This could be a problem however if you are on a tight budget, as ECS seems to make some of the cheepest boards around. But hey, you get what you pay for.
Long winded but hopefully helpfull,
6string
