Something else is at play here. If your source is showing 115V where it originates, but you are not showing 115V at the terminals of the power supply, the only possibility is that the wires are not terminated to those terminals. My best guess is that you have clamped down the terminal pressure plates on the INSULATION of one of the wires, not the conductor. A stray strand or two may have been touching originally so the meter could read it with no load on it, but the moment there was a load, that tenuous connection vaporized and is now gone. That is the ONLY explanation that makes sense, because no matter WHAT is happening inside of that power supply, i.e. a PC board trace burned off, etc., the LINE TERMINALS should still show the incoming line voltage.
Also, you said
... And across the input...
Hot and ground using dmm in AC V mode
can no longer produce the 115 vac tho,...
You should never read Hot to Ground at the local site, because that depends on the integrity of your ground connection to the local site. You must read from L to N on the line terminals of the power supply, nothing else is valid.
If you wired it with only one hot lead and used ground for the Neutral, you have violated code in the US and need to redo this properly. That integrity of the ground is the very reason this is not allowed, because in a single phase system like this, the Neutral is considered a current carrying conductor, and you are not allowed to use Ground as a current carrying conductor, other than at the bonding point of the service entrance.
If none of this made sense to you, please hire a professional.
Side note:
"Meanwell" is the worst company name I've seen in a long time. "The quality isn't that good, but they Mean Well"... is what comes to mind every time I see it. Likely their company name was translated directly from Chinese.
