PowerBook G3 Won’t boot, only boots to open firmware

Looks like the Powerbook Pismo, if that is what you have needs the firmware update found on article 75132:

Knowledgebase links of the info.apple.com format no longer work

https://web.archive.org/web/20080917231552/http://docs.info.apple.com:80/article .html?artnum=75132

is the version 4.1.8. You'll need to obtain a copy of the 9.2.1 retail installer to install it on your Mac.

There is something simple that might get you started; it is at least worth a try.

Sometimes odd startup problems on a Pismo can be due to a weak or dead internal backup battery. Most of us call it the "PRAM" battery for convenience. Fortunately the Pismo allows you to easily disconnect the PRAM battery's cable from the logic board and that often stops those frustrating startup issues.

Remove the keyboard per instructions in the first image in this article:

PowerBook G3 Pismo PRAM Battery Replacement - iFixit

Now look at the SECOND image in that article but DO NOT take the action described. Instead look at the RIGHT EDGE of the second image. There is a twisted cable with white, black, and red wires going to a white connector that is plugged to the logic board. Detaching the white plug from the logic board disconnects the PRAM battery. It is not a 100 percent success rate but many people here having trouble starting a Pismo have reported this action allowed booting.