Yeti 400 not charging - replaced lead acid battery

First lead acid battery would not charge. No ‘blue light’ at the charging power supply port and no charging indicator on LCD. Purchased a replacement lead acid battery. Let unit sit without battery for an hour before installing new battery. New battery will not charge either. Same issues. LCD is functioning as it now shows battery at 20 percent (several months of not charging).

Bad power supply unit (cable and brick power supply for wall socket charging)? Can I test the power supply?

Is there a 400 unit reset I’m missing after battery install (other than letting unit sit with no battery for an hour)?

Thank you.