non working inverter came into the shop. dead on arrival. called the manufacturer that managed a replacement.
then they left it "to disposal according to your country laws"... so I opened it. battery was not plugged in ...
Not quite on topic, but fits in well with your story.
Back in the '60s, a lot of farmers weren't on the grid & had 32v DC power plants.
Nobody made TVs to work on that supply, so they bought electromechanical inverters which used a very much "scaled up" version of the "vibrator" supplies used in old style car radios.
A country customer came in, wanting to buy one while he was in Perth, but when the counter attendant went to grab one from the store,"the cupboard was bare".
The counter bloke's eyes fell upon the one on display.
Sure enough, the exact thing, & the box was even there.
The sale was made, the customer went away happy, all was flowers & unicorns, till the Boss noted the counter display unit wasn't there.
You guessed it!
The counter one was a dummy with no active guts, just a few weights to stop it being easily nudged off the counter.
Luckily the Boss knew the customer well, so could make a good guess where he would go next, & "headed him off" before he set off for home.
Meantime, us lesser mortals were sent on a hunt to find an inverter "by hook or by crook"!
From memory, one of the country branches had one, which was quickly shipped prepaid to the customer's business address.