Because one active thread about EL84 based integrated amps is not enough! Bought a gold face X100 in "doesn't turn on" condition. Naturally it had a blown fuse of the inappropriate variety. Replaced the fuse with a 3A (if memory serves) slo blow, installed the tubes after testing (hey - my second tube rectified Fisher!), of course the 12AX7 half of the original Fisher marked Mullard 7247s were both just under spec, probably good enough for now, then hooked up some speakers and gave it the old DBT. Appropriate background information aside: I have been testing Fishers with an I think 40 or 60 watt bulb for a while and usually they sort of start out bright and dim anywhere from 20% - 50% within maybe 10 seconds as the capacitors charge etc. Done at least 15 tube Fishers with this bulb. I have read here that a bulb of this wattage is a bit low, and can appear to not dim... I just haven't experienced that. Okay, back to problem... During the DBT I got such an imperceptible dimming I can probably attribute it to wishful thinking. I retested without the rectifier in circuit and got the same result. Rectifier is a vintage RCA big bottle type that tested great. So, in addition to sourcing a 100 watt light bulb and testing whether this is my first outlier, I ask: Say I did fail the DBT, what can suddenly go bad that would make it fail? I found the green and brown twisted wire leads to the "I'm on" indicator jewel light were really tight against a chassis edge but relieving them didn't change the bulb glow. Death cap? Thoughts appreciated. Sorry for the lengthy post and many pictures. Shall I just replace the usual bits and retest?