Erm. Might I suggest magnification. Those bodge wires need to be 5x smaller, you have solder joints touching ground plane (probably thru soldermask, but still). Looks like its somewhere near ram, thats a critical area.

Have you measured voltages when trying to turn it on?

The first picture is the wire that I used for the jumpers. It's a very fine radio coil wire, but I don't know the gauge of it, and don't have a way to measure it. I put heat shrink over it to prevent any chance of shorts, even though this wire is enameled and technically short proof as it is. I have, however, found proper jumper wire on Amazon, some of that 0.02 mm stuff that looks to be noticeably thinner than even what I used, so I will get some of that today, as well as some ultra fine soldering tips for my iron. The one that I used (I have a Hakko FX-888D) was pretty fine, but didn't have that necessary ultrafine needlepoint like the one I found on Amazon. As far as touching the ground plane, what would be the best way to keep solder from flowing onto that? That is one thing I have never needed to know how to control in such a small environment until now.

As far as checking power with the computer plugged in, I need to get smaller probes for my multimeter before any powered testing is done, so I have not yet been able to do those types of diagnostics. Mine is fine for point-to-point wiring, but not for much else, so I will acquire some finer probes (or probe adapters) on Amazon as well. Furthermore, this computer essentially has it's boards in a sandwich (second picture), so accessing many components will be rather difficult, unless there is some technique to testing this type of setup that I don't know about. I really am a Greenhorn when it comes to computers, my primary experience with repairing electronics begins and ends with vacuum tube tech.

Thank you very much for your help,
Forrest

needle tips are junk, too small to transfer proper heat. What you want is microscope (or at least good loupe) and flux so the surface tension does all the work for you. I get my thin wires from inductors/chokes found in garbage pile of scrap electronics.

Good trick for places you cant reach with multimeter probe is soldering measurement wires.

Wow, those loupes are pretty neat. I don't know why I didn't have one of these ages ago. Considering my price range, I think I'll see if this works before I upgrade to a full microscope.

As for liquid flux, can I use that with rosin core solder, or is there some other type of solder that is needed?

Also, thanks for the tip on soldering leads to components to test them. I had long since forgotten about that.

Which loupes? I wouldnt spend any money on loupes (and especially not those wearable "magnification glases", those are a scam) considering $50 gets you usable USB andonstar microscope, and $60-70 standalone LCD one.

My choice to go with a loupe was influenced by the prices of the microscopes when I first looked them up. Whatever I typed in got me the incredibly expensive laboratory scopes and not the scope that you mention, which is considerably more attractive in price and size. I will pick up one of those in the coming days as opposed to a loupe.

This was the loupe I was looking at, but now with finding out that I can get a USB Scope for $37 dollars, I'll get that instead.

Loupe: https://www.amazon.com/gp/product/B07ZT5HGM5/ … ZYG79KHNU&psc=1

Scope: https://amscope.com/products/utp200x003mp?msc … f9&gclsrc=3p.ds

Once I have the scope in my possession, I will come back here (in a few days) with a board that will have it's broken traces properly repaired.

Thank you for all your help thus far.

EDIT: I actually found on Amazon a USB scope that gets better reviews than the one I initially found for only two dollars more. Here it is if you'd like to take a gander: https://www.amazon.com/Plugable-Microscope-Fl … 49059547&sr=8-4

bad https://www.eevblog.com/forum/blog/eevblog-56 … 212/#msg1181212
zoom is not adjustable, only focus. The problem with absolute bottom of the market is there are lot of scams (like loupe glasses) and garbage products and you end up buying a couple before landing on something usable. Good optical stereo microscope starts at <$200, so only makes sense if you are planning on using it in more jobs.

https://www.youtube.com/watch?v=H2P1_JZYnVc

You can also look for a local hackerspace, they usually have the tools and someone might even be able to help you with soldering.

Okie dokie, I decided to measure some voltages before I did anything. Firstly, I plugged in the computer, and this time I didn't get a glowing amber battery status light. The lights on the charger remained green and never flashed an error, so that is a peculiar departure from the last time I applied power to this system, which had both an amber battery status light and flashing charger.

I removed the boards from their case and began measuring some chips along the underside of the bottom board. About halfway across the board, the chips lost all voltage, and the battery charging terminals only measured 27 mV DC (regardless of whether or not the power button was pushed). I must say that I do not know if voltage is applied only when the battery is inserted into the computer or not, perhaps as some type of safety feature.

While I was measuring one chip's voltage (which was somewhere in the neighborhood of 16 VDC), my probe slipped from my hand and caused an arc between the chip and a through hole diode. The chip still measures voltage, but I don't know what, if anything, happened to the diode. Regardless, I have a donor machine coming in the mail soon, so I'll have some breathing room for any damaged or defective parts.

I will also note that there is no heat or burning smell coming from anywhere on the boards.

With this info, what do you think may be causing this? Has my probing yielded anything usable, or should I keep measuring?

EDIT: this computer does have conventional electrolytic capacitors near the power input section. They look okay, but would it still be worth it to replace them to see if that could possibly be the culprit of no power? Again, I grasping at straws here, so I am throwing anything at the wall and seeing what sticks.

Edit 2: I have found one swollen capacitor (it's top is bulging) that is linked to the battery charging port. I think I am going to replace all the capacitors in this computer. This capacitor has the label of:

C4
100
6V

The picture is of the capcitor in question.

After this post I would suggest you watch a lot, like at least a full month worth of videos, of:
https://www.youtube.com/c/Voultar/videos
https://www.youtube.com/c/NoelsRetroLab/videos
https://www.youtube.com/c/JanBeta/videos
https://www.youtube.com/c/kore464/videos
https://www.youtube.com/c/GadgetUK164/videos
https://www.youtube.com/user/lukemorse1/videos
maybe even https://www.youtube.com/c/TRXLab/videos if you can stand listening to 40 minutes of solid theory before the fix 😀
russian recommended but not required:
https://www.youtube.com/c/Remonter/videos
https://www.youtube.com/c/Service-coreUa/videos
https://www.youtube.com/c/%D0%A1%D0%BF%D0%B5% … B5%D0%BB/videos
https://www.youtube.com/c/LangeronLgUa1/videos
https://www.youtube.com/channel/UCIHSBp0MiQDV … dQuS_BfA/videos
https://www.youtube.com/c/TerabitLab/videos
https://www.youtube.com/c/VIKon-msk/videos

While binging on videos visit local recycle center and pick up a couple of garbage electronics - broken laptops/desktops, home players/amps. Use those to practice soldering and measuring.

These videos are awesome. I don't think I would have ever found these on my own.

Thank you so much.