Laney VC30 run away bias

[technicalxpectations]

Have a Laney VC30 on the bench. Owner had been powering it with generator and then HT fuse went. Reports that after replacing fuse, 2 of the 4 EL84's get hot and volume drops. On bench I checked bias on all 4 EL84s. Two are at about -15mv and the others start at about -18mv and climb gradually to -250mv (cut-off) or more. Replaced a couple suspect leaky caps which made very little difference. Not that familiar with cathode bias amps. Any suggestions?

[mooreamps]

the control grid on the power tube(s) is not seeing ground.