I posted here many years back when I first needed some fan repairs. EchoWars was all help with that and this amp has served as a sub amp for 7 years. The history is I purchased this amp for the cost of repairs were it was abandoned by the previous owner. I have less than 200 bucks in the amp. Recently the amp has developed a hum and some intermittent sounds that to my non expert ear sound like a component in the audio path. The sound is scratchy and airy much like a dying transistor. So I have questions and have a refurb plan, but would appreciate your feedback on this. 1. I have disassembled the amp. the power board and heat sink are out. I have thus far resoldered the entire transistor to heatsink mounts (with Sankens out). The Sankens and insulators are cleaned and back in with fresh heatsink compound. The fan is not that old and still quiet, so just new dampers on it. 2. I have identified some faulty components in the protection circuit. Qf15 / Rf59 /Df11 & Df12 are looking bad and I am sure this transistor is burnt up. There are several items that have questionable solder joints and of course I will resolder all suspect joints. 3. All the electrolytics are original excepting for 1 or 2. I plan to replace every electrolytic capacitor including those GIANT 18000uf 160V cans. Questions: Mouser has ChemiCon E36D161HPN183ME92M standard type capacitors in stock. Is there anything wrong with using a Non Audio grade cap in the main caps positions? Have I chosen the right dimensions? I have all the caps and relays and more items in a Mouser cart right now. very reasonable I think. Qf15 > currently that burnt transistor is an A1837. This is also the only place in this amp that I can see a non original transistor and some previous repair. I plan to put NTE288 in that position and rebuild components around it. Could this transistor cause the intermittent audio I experienced? Df11 & 12 are W06B I plan to use 1N4003 is that good to go. I want to replace all those W06Bs on the boards. Is there a better part to use for Qf15? Should I replace Q14 to something related to the NTE288 part? What operational items should I check that may have led to the failure of Qf15? This looks like the 2nd time to repair this circuit area.I have the full service manual Thank GOD but I am still not an EE just a long time hacker, Im much better on Tube Gear. Still so much of the symmetry of this schematic is so similar to tube amp topology. Especially the diff amp configs and the splitters. When i put it all back together I am considering some staked in turrets to eliminate this pin wrap crap. Also want to upgrade speaker binding posts but after searching here and other places just not sure the best product within reasonable money. Are there any upgrades that I need to consider since the post several years back on here where the thread was the OnSemi transistors. How can i test these Sankens if they are so static sensitive? Ok thats a LOT of questions and I have a few more concerning test setup. to be continued Thank you if you read this far down.