The downpipes are frozen or if you have gutter extenders those are.
If you have gutter extenders, tap them gently with your hand. See if ice bits come down the pipe. Pull them out, repeat.
Then tap the downpipes briskly but not violently with your hand. You don't want to break a joint, dent the pipe, etc. Do you hear ice rattle and hopefully fall?
Go back to the outflow part, scrape ice out that fell. Hopefully some water too.
Repeat in a while during warm part of day. Keep outflow area clear and remember everything has to slope down.
Worked for us.