On Mon, Feb 27, 2023 at 10:29 AM jake utley via cctalk <cctalk(a)classiccmp.org> wrote: I would certanly recomend keeping it original. My experience is that a linear supply, although less efficient than a switch mode one, is a lot more reliable. There's a joke about the crazy PSU in the Zenith ZVM1220 MDA monitor thst said unit combines 'The reliability of a switcher with the efficiency of a linear'. It's also a lot easier to fix a linear supply than a switcher and there are not high voltages on any of the semiconductors. Getting back to the 380Z, there's a schematic of one version in the service manuall. But even if it doesn't agree, you can trace out a schematic in under an hour and that's going slowly. It is a very simple unit using normal 3-terminal regulators in the standard way. I'd 'megger' the transformer just to be safe as the machine seems to have been stored in poor conditions. Then power it up with a 'lamp limiter' on the mains input and no load on the output (unplug the cables from the driives and the 1 or 2 10-way ribbon cables from the PCBs). Most likely it will be fine, even with the original smoothing capacitors. -tony