Bricked Iconia W510 tablet with Windows update

Just wanted to put out a warning to anyone still using this tablet.  (Note that it has no external SNID markings, so you can't get a SNID or serial number unless you can get it to boot, and you thus can't use the Acer online chat support facility, as I explain below.) 

If you have this unit, do NOT allow the updater to install any portion of the latest Windows 10 update to your micro SD card even if your main drive has insufficient space.  In that case, pass on the update completely.

Here's what happened to me:

I upgraded my unit to Windows 10 a couple of years ago and have had no trouble with it since.  However, the system told me yesterday that there were updates that needed to be installed, so I said "yes" to the installation.  I then got an error message saying there is insufficient space to do the updates and that the system needed 5 gb more space.  (This surprised me as there is ONE added app -- JRiver Media Center -- and no data whatsoever on this machine.)  A picklist gave me two options: clean up the disk or use the empty micro SD card mounted as the D drive. 

I chose the latter.  Big mistake.

When the updates completed, the unit was to reboot.  But nothing happened.  The screen went black.  I held down the Power button and, for about two seconds, I got the Acer logo and the message "beginning automatic repair" (or words to that effect).  The unit went black again.  I did research on the web and determined that I should hold down the Power and Volume buttons at the same time in order to get into BIOS and that, when in BIOS, I could either restore to factory defaults or boot from an external device.  However, when I held down those two buttons, the BIOS screen came up for about two seconds and the unit went black again.

I repeated both using Power alone and with Volume a few times.  I went through both routines with the micro SD installed and removed.  At best, I got two seconds of logo or two seconds of BIOS before going black.  Mostly I couldn't even it to boot for two seconds.  The unit is well-charged and should have plenty of power, so I assume this is entirely a software issue due to the Windows update.

I tried Microsoft support chat, figuring I would start there because it was a Windows issue.  They told me to contact Acer if I couldn't get to the recovery console.

I contacted Acer.  I couldn't use the chat support here because this unit has no visible SNID and I can't get to the screen in the OS that would give me that information, so I called warranty support just to find out how I could get access to the chat support without a SNID.  The agent was useless.  He couldn't help with that and he said he wasn't trained in software troubleshooting, so suggested that I transfer to fee-based out-of-warranty support.  I allowed him to transfer me, but even that agent was useless.  He told me to take the unit to Office Depot or Best Buy and pay for a repair. 

I might do that, but, at this point, I am probably going to take it to recycling and be done with it.  It doesn't have much value if it can't be updated because there is insufficient storage space for upgrades even when almost nothing has been added to the original factory setup.

If anyone here has suggestions, I will be grateful for them, but, based on the solutions I have seen on the web, I don't think I can do anything if I can't get the unit to power on as far as the BIOS setup.