Hi Guys- pretty much my first post here, although a long-term lurker and Fender user. Had a lefty Jazzmaster back in the 60s, have a hybrid tele (American Standard neck, Warmoth blonde body, Callaham bridge, 4-way switch), a Squier Precision bass and a CV Jazz bass (along with about 15 other guitars and 5 amps). I have a red knob Champ 12 with some mods and I built the BYOC Tweed Royal amp from their kit (along with about 10 of their pedal kits). But the reason for this post is that the bass player in my old high school garage band gave me his non-working silverface Twin Reverb (non-working like a decade or two ago- stored in the basement since then). The transformers all date from late '76, it has a MV with pull boost. It had a blown fuse which I replaced. Symptoms are- when you turn it on it's "fine", but when you flip it off standby you get sound through the speakers for about 30-45 seconds, then breakup, then a hum builds up and the power tubes start to redplate. I put together a current limiter with a 150 watt bulb and when powered through that the tubes don't redplate, but when you switch from standby to power the current limiter bulb glows much brighter. You get reasonably good sound through the amp (at reduced power), all the controls work except reverb, most pots are scratchy. I pulled the chassis and it looks pretty much stock! The only visual flaw I can find is a cracked (screen?) resistor on V9 (the 470 one). OK, my first time really troubleshooting an amp (and it's a TR....). So is the cracked resistor "the chicken or the egg"? Did a failed power tube cause it, or could it just fail. Is that a reasonable cause for the redplating, or something else going on? I haven't gone on to any voltage checks yet. I have the capacitor discharge probe I made when I built the BYOC amp. Also- I'm assuming at least some (most?) of the caps should be changed out on this 45 year old amp? Filter caps for sure, most of the big blue molded board caps? Anything else that should get replaced due to age? I love soldering! My objective with this amp is to 1.) Get it running right, 2.) Most likely Blackface it, 3.) Possibly do the Jerry Garcia mods to it (although I already have the SMS preamp so there's really no need to go that far). Thanks for the help!