Thank you. Although I had plugged the computer in for 30 minutes and tried the SMC reboot several times unsuccessfully, I left it plugged in. After charging all day, it is actually working again. Phew! I assume that in my reassembly I tightened/connected something better and it needed the full charge to get it operational.
I followed the instructions, seemingly without problems, but the laptop won’t power up now. I have disassembled and reassemble twice, but haven’t found anything obviously missed or out of place. Any ideas on what might be preventing it from charging and restarting?