How To Fix Powerplant In Heartgold?

First you have to go to the power plant and talk to the manager. Then go to misty's gym in cerulean city to find the burgelar, then go to the bridge outside of cerulean city and talk to the burgelar there, then go back to misty's gym and surf in her pool and press "a" when you're infront of the rubber tubes and you should find the missing piece (place is not exact). Then take it to the fat manager and there you go. Although if you need to wake up the snorlax and fight him as lvl 50, talk to the guy in the radio place in lavender town who was running around infront of the elevator after you fix the power plant and he should allow you to play the pokeflute. Just play it and talk to snorlax and there you go

You have to go to cerulean city gym and a team rocket grunt bumps you and then he gose to route 24 and then he battles you he has a golbat.when you beat him he tells you where the machine part is it is be hind the blue umbrellea at the end then bring it back to the power plant