I was using a 5V1 1/4W (surely it's not 1/8W?) in a linear PSU I made, and it would pass up to 20mA sometimes, maybe even 30mA. LTSpice said it would barely pass 1mA, and that was at 120Hz peaks.
So I tried a 2v0 and 3v0, and they burned out too, during a test of about 15V at 300mA of the PSU. So now I have a 1/2W 5V1, if thtis burns out, I'll try a TL431.
The schematic used a 1/2W zener, and I guess it will get pretty hot. 1W zeners and expensive
I guess there's no question here, I'll try and see if 1/2W zener survives.