Opened this one up late Saturday night and did an initial spraying. I wasn't the first in there. Bottom wooden trim is missing. Label fell out the bottom and said "Tampered" followed by several numbers. Saw some traces on the main board were re-soldered. When I looked on top I found the large main fusible resistor, I think that is what it's called, had been broken and put back together. Not sure how but there is some silicone spread on the outside. I can see a solder joint between the halves. Sprayed some more and put it all back together. Much better but still had some prob with the right side. Started pushing, turning and flipping. Found the bass tone lever was "popping." Got back into it tonight and really washed down the switch. Now it sounds great. Checked the dc at the speakers 7.8L and 1.0R. Let it play for a couple hours.
I was curious so Sunday, I went back to the lady that sold it. Her husband was there. Asked him about the jumpers but as it turns out, even though he is an EE, he didn't do the work. He had bought from someone who had started working on it and never finished and had lost the pre-amp. The EE had the pre replaced and repairs done at a cost of $175. Appears to have been a good job but I didn't find any shop sticker. So a clouded history.
I did pass on another 8080DB at the GW a month ago. It was missing the small Dolby knobs. $50. Cosmetically, case was better than mine but I'm really trying not to add anything unless really desirable or really cheap. I not big on flipping as it can be too much trouble so hopefully an audiophile gets what I leave. The other option is if I know someone is looking for something. The 9090DB is sitting under the kitchen table for now.