Luxman R-1040 Stereo Receiver
I traded a friend for this vintage 70's stereo receiver. It was sitting on the ground in a storage shed so I wasn't sure it was worth the effort to carry home, but it turned out to be in quite good shape. It was missing most of the original knobs unfortunately and was pretty dirty, but it cleaned up nice and my friend dug up some reasonable looking knobs for it. They'll do until I can try to find original replacements.
The pictures below illustrate how to make smoke (and possibly fire) come out of your stereo receiver. There are 10 fuses in the receiver and someone wrapped 9 of them in aluminum foil. I figure the 10th one wasn't wrapped because it is under the chassis out of sight. This is not good because if you let the smoke out it won't work anymore. ;o)
Amazingly, when I installed the proper fuses and powered the receiver up none of the fuses blew, even though there is an obvious problem on the driver board (visible in the 3rd picture). Everything worked except the FM tuner.
I pulled the FM tuner and checked the FET for the RF amp, and mixer and oscillator transistors but found no problems. However, when I reinstalled the tuner it worked. Most likely a bad solder joint somewhere.
I recently bought one of the Chinese-made vacuum desoldering stations on eBay and it paid for itself with how easy it made taking this tuner out. And without damaging a single PCB trace.
The driver board had one obvious problem (see the first picture below for details). Rather than regluing the transistors I applied thermal grease to the junction between them and shrank a small band of heat-shrink tubing around the pair (saw this on another website for an R-1040 rebuild). This way a bad transistor can be more easily swapped out. This was done to the transistor pairs on both channels.
The receiver chassis cleaned and repaired, ready to go back in the cabinet. Before reinstalling the chassis I adjusted the amplifier idle current and voltage per the service manual.
The receiver is still running on all the original capacitors: I didn't find any leaking or swelling electrolytics so I left them be for now. And it has all the correct value fuses now - no more tinfoil fire starters. Just wish I could find those missing original knobs.