marshall that whistle

[psykose]

hallo all

i have a litlle problem with a repair.
it goes about a marshall jcm 2000 TSL 100W head

the things i already found was that the mains transformer was burned
by an glow wire that was in short circuit.

so i also retubed the amplifier (it was also a request from the owner of the amplifier)

now when i turn the amplifier on i hear a whistleling sound

i'am out of possible solutions to this problem

greetz psykose

ps: sorry about my english

[psykose]

i think i just figured it out it came from the reverb tank