Hello! AK newbie here looking for advice on restoring a KR-7070. I got it on eBay and the only thing I knew was that it powered up. The unit is in lovely cosmetic condition with an ok-ish plywood case. All switches are snappy and the glass is virtually scratch-free. After unboxing I tried it out and I only got sound on the right channel. It sounded lovely. The left one appeared to be completely dead. Firstly I discovered a shorted emitter-collector on the power transistor Q2 (2SC898) and I thought that'd be all but it turned out there was more damage on the main amp board. The obvious was a couple of very crisply fried or cracked resistors (Re33, Re43, Re45, Re47), while the not so obvious was an opened transistor Qe9 (2SA566). All other transistors passed a basic test with a multimeter without unsoldering anything, including Qe7, which is right next to crispy resistors. I marked all failed components with a red dot on the schematics and a couple of never-installed resistors with a blue dot. Interestingly, the schematics gives Qe7-8 as 2SC484Y and Qe9-10 as 2SA484Y but the installed transistors are 2SC680 and 2SA566. There's also an extra 120 kohm resistor between the base of Qe12 and the emitter of Qe14 that isn't on the schematics. As far as I can tell it appears to have come like that from the factory. The resistors Re43 and Re44 are also a bit of a puzzle as the schematics says 33 ohm each but colour-decoding Re44 gives me a 68 ohm one. Re43 was probably the same but it it's too discoloured to tell. Now, apart from the obvious replacement of resistors and some/all capacitors I'm wondering what to do with the transistors. Both 2SC898 and 2SA566 are hard to obtain. A generally available modern replacement for 2SC898 is MJ21194G and for 2SA566 it's MJE15033G (learnt that from other posts on the AK forum, thanks!). Should I try to get genuine 2SC898 and 2SA566 and replace only the failed transistors or replace the failed transistors with their modern more-or-less equivalents? Or should I replace all of the power transistors Qe1-Qe4 with MJ21194G, Qe9-10 with MJE15033G and Qe7-8 with MJE15032G (the modern equivalent of 2SC680)? Mind you I gave up the practical side of DIY low-level electronics more than 20 years ago and now I'm slowly getting back into it. I'm also curious what triggered the failure if anyone can tell from the schematics and the failed components. Later work: tuning meter and stereo decoder don't work. I think the stereo issue is due to a failed lightbulb in an opto-isolator (early model of lightbulb + photoresistor).