Dead amp. It never looks right,to me, to use 1/3W anode dropper resistors, even if high voltage type. Did Marshall stop using HV types, these are light green body if suggestive of anything?
100K open circuit one to V2p2. 2x seriesed 47K 0.5W will go back in there and its mate. No discolouration to the coating, scraped back coating and normal under the axial sampling I scraped off ,dark grey MO spiral, failed at one end. To last but 2 turn measured 63K, to last turn before end measured 110K. Presumably failure by gradual oxide breakdown by micro-arcing and thinning and resistance increase. Another problem waiting to happen, especially if rough handled/knocked on front. There is a sub-front panel in these , rivetted to the pcb. Unnecessarily long landing tongues protrude across the pcb and their edges are about 1mm average gap to component leads, gap to one resistor about half a mm.- posted
9 years ago