A Proud new(ish) owner of a C128 (that doesn't work)

Fairly recently I got myself a C128. As much as I wanted to just fire it up and see what happends, the sensible side in me told to do as many checks before actual power-up as possible.
So I did a visual inspection of the motherboard, nothing obviously wrong with that. The next thing to check was the PSU. I plugged it in (without C128 attached to it) and was happy to see that it didn't blow fuses, explode or anything like that. But then I did check voltages, the 9 volt AC line seemed fine, but the 5 volt DC not so much. It actually was outputting over 10 volts! So it is obvious that the DC-regulator is broken.
As far as I could tell the PSU works basically so that the network AC (in this case 220 VAC nominal, as this is a west-german PSU) is fed to coil transformers that decrease the AC voltage down to 9 volts. For the AC line, that is just about it, nothing fancy and not much that would break. But for the DC the AC voltage is first rectified and then regulator will step-down the voltage down to 5 volts (atleast when the regulator is not just shorted)
My first idea was to diagnose the original system and simply repair or replace what is broken. But after a while I came to the conclusion that it might be easier to basically make a completely new regulator, assemble it on a daughterboard and then just gut the DC-side of the PSU and replace the original DC-regulator with completely new.
I know there would have been even easier ways to get the 5 VDC... But on the other hand, as fun as it would be to just have something that simply works straight out of the box, doing some repair work and restoration is something I wanted to do. By doing this repair I should get atleast an original C128 PSU, even if the DC-circuitry is going to be completely new.
So far I have selected the components I'm going to use, I have very little experience in electronics design so much of it was completely new to me. And to be fair, I'm a bit excited to see if I can actually do this thing. Some of the components have not yet arrived, and because of many reasons that are not related to this project, I don't really know when I might have anything new to tell about this project... But eventually I will continue work on it.

New components

I Recently got another shipment of components... Maybe it's just bad luck, but for some strange reason I couldn't get all the components from any single provider. And even now I am still waiting for a SIL-socket that I intended to use as a socket for a fuse. But it is not really necessary, and most importantly it would have the same hole pattern as the fuse, so for now it won't stop me from finalazing the design of the daughterboard PCB.
Once that is all done, I'll make the mask and PCB... Atleast that is the plan.


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