My pbp is a sleek, black, flat brick, and won't boot from any kind of media

[rotwang]

I'll echo the above advice,, leave SPI alone, unless you KNOW that you have written to it
As i said above, manjaro has put out bad uboots,
unless there is a specific KNOWN advantage, leave a working uboot alone
A emmc adapter is not so expensive, ameridroid might be quicker
When you have emmc out, you may try long presses as above
Does it go without saying?? after long press a regular 1-2s start press,
a quick tap is NOT enough
For SD cards, the best start with "S", some others are OK, but usually not as good
I prefer samsung

Alrighty, on the advice of y'all I'll get the eMMC adapter (and some more SD cards) and try re-flashing the eMMC on a different machine. I'm fairly confident I'll be able to get it to boot that way. I think it's less about the cost of the eMMC adapter than that I don't want to wait for it to come in the mail! And it will suck even more if I get the eMMC booting and still have to send the PBP back to get the SD reader fixed.

Thanks yos, I'll let you know how it goes!