model m6 498 does not turn on
my old very old iMac, model M6 498 will not respond to turning it on. nothing
model m6 498 tells us nothing about identifying the model and year of the Mac. From what you've said we can only guess that the power supply is toast. If the Mac is older than 2011 it's considered Obsolete by Apple and will be near impossible to fix due to no parts available.
So with the info at hand can only recommend getting a new Mac.