UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Marshall JTM45 Guitar Amplifier- Mains (Primary)Fuse Blows

'LIVEWIRE?' · 11th Aug 2018, 10:49 am

Thanks, everyone for your suggestions. B.t.w., the amp is a 1990 production version with the small components mounted on a fibreglass PCB. The rectifier is a GZ34, and the o/p valves are 'GT' KT66 x 2, although a maker's plate on the amp. chassis states that they should be 5881's, which should 'only be replaced with the same types' I won't be back in the workshop until Monday, but will follow the advice given. Martin, the message I got was something to do with the biassing, so maybe the o/p valves are at fault. Now to look for some 1.25" 2A (T) fuses!

11th Aug 2018, 10:49 am	#5
'LIVEWIRE?' Rest in Peace Join Date: Mar 2006 Location: N.W. Oxfordshire(Chipping Norton) Posts: 7,306	Re: Marshall JTM45 Guitar Amplifier- Mains (Primary)Fuse Blows Thanks, everyone for your suggestions. B.t.w., the amp is a 1990 production version with the small components mounted on a fibreglass PCB. The rectifier is a GZ34, and the o/p valves are 'GT' KT66 x 2, although a maker's plate on the amp. chassis states that they should be 5881's, which should 'only be replaced with the same types' I won't be back in the workshop until Monday, but will follow the advice given. Martin, the message I got was something to do with the biassing, so maybe the o/p valves are at fault. Now to look for some 1.25" 2A (T) fuses!