My grandfather has a R87 that's been acting up over the past year or so, and its gotten to the point to where it simply doesn't play anymore.
It first started out as what I assumed was a broken solder joint after putting the puzzle pieces together... My grandfather had used a toothpick or a sliver of wood as a wedge on one of the connectors (P207) on the Mechanism Control (4-07221-02) and everything seemed to be fine for months at a time. Every time it would act up, he would just fiddle with the position of the wedge and it would be good for another month or 2.
A few weeks ago, the audio would cut out completely, the table would not turn, or the record would be put on the table, stylus would touch the record then go back to resting position and the record would be put back into the carousel- This would repeat indefinitely until the power was turned off and back on.
tl;dr below to skip story
I wanted to start with the easiest fix and work our way to the more challenging ones. I had taken all of the contacts out of the connector (P207) that was giving us trouble, and very lightly sanded the face of the contact that touches the pins on the mechanism control board. I pried the contacts slightly out so I would be sure they were making contact with the board's pins. (Yes, I also pried the tiny tabs back out so the contacts would stay in the connector.) It worked for a few plays then started acting up again. It seemed wiggling and positioning the wires in a certain way would let us play multiple records at a time, but as my grandfather pointed out, the whole carousel would jerk and the wires would move ever so slightly which would cause a connection to break. I suggested we take the whole board off and make sure there's no burnt/loose components. We had a quick look at how the mechanism board was held on and realized its just a single screw holding it in place. We took it off, and I had a look at the back of the board. Sure enough, there was a cracked solder joint on one of the pins. I put a small dab of flux on the bottom side of the pin, and melted the joint back into place with my soldering iron. I looked around the whole board for browned components or iffy connections. I questioned the capacitor on the board, as the bottom looks like its slightly bulged out but there was no corrosion from a leaking electrolyte so I dismissed it. Other than that, it seemed the broken joint was the cause of our issues. We put the board back in and it played at least 15 songs. I went home that night and got a call in the morning about it not working again. So, I headed over to his house and took the board out again.. As soon as I had the housing in my hand, I could see a nice brown burn mark on the back side of the construction paper used behind the PCB. It apparently lit up the trace that connects to the pin, but I remember double checking after I reflowed the joint to make sure there wasn't any solder touching the adjacent pins. I inspected the board once more and looked for burnt components... none. Just that rouge pin that got so hot that the board connector is solid brown right where the pin slides in. I stripped about 5 inches of an aux cable and took out 1 of the insulated wires. I made a jumper from the pin where the trace was burnt to where the trace ended up on the board. After that, we put it back in. It would play a song but it was pretty quiet and it would start at near silence and build up to about 75% of the volume it should be. After 3 songs, the audio would cut in and out and finally it faded to silence. This was a few days ago, and now I'm here looking for help.
tl;dl - Connector P207 on Mechanism Control 4-07221-02 had a broken solder joint, resoldered it, it nearly burnt a hole in the paper behind the PCB after the "fix," put a bodge wire in because trace was fried, played a few songs but the audio would fade in to almost correct volume, and eventually stopped playing audio once again.
I can't really afford to to buy a working board, what can I do to fix this?
If anyone is interested, I have an idea that would essentially replace the whole carousel with $25 in parts, which I can afford. It involves Arduinos and breakout boards.