Took the back off to clean the fans, no power or charging lights etc

I took the back off the clean the fans, I usually do this every 6 months or so since I bought this in 2018 without issue. This last time I took the back off, disc the battery, it is unplugged of course, clean the fans and after putting it back together, no power, no charging light with or without the battery or charger in. Worked fine before I cleaned it and not my first time doing so, so what could be the issue and has this happend with this model with others before?