It sounds like you may be hitting the issue described in for example Belkin RT3200/Linksys E8450 WiFi AX discussion - #4000 by wavejumper00 and Belkin RT3200/Linksys E8450 WiFi AX discussion - #4085 by Lynx where a bunch of peoples' RT3200/E8450 couldn't start after a power cycle with no LED activity just as you, which the probable root cause was identified in Belkin RT3200/Linksys E8450 WiFi AX discussion - #4002 by daniel.
@daniel can probably advise you how to fix it, or post in the linked thread about your issue.