might not be the drain pipe
its usually the sump hose clogged or pump jammed
with the plug out , remove the lower white back panel – the sump is the black pipe at the bottom of the drum, just be ready with towels and a mop, the waters gotta go somewhere
check the pump housing too (the pums on the right, attatched to the black pipe)
of course, it might be worth dropping the waste hose into a bucket, lower than the water level.. if water comes out, its the sump/pump
oh, and watch for sharp edges, and try not to spill any water on anything electrical.. i.e the motor!!!
hope this helps