JVC tt-101 repair

I just know my limits as far as electronics repair. I’d rather not destroy a nice piece of equipment when there are others that have the skills to fix it. I respect that.

I’ve been conversing with Dave Brown at modularsynthesis.com. This is what he relayed to me about the TT-101


"Dave Brown <davebr@modularsynthesis.com> May 16 (2 days ago)to me

I believe that turntable uses a double sided PCB but without plating, so there are no connections from front to back. The way they solved this was by putting eyelets in the appropriate places and soldering them on both sides. The issue is there is a difference in the coefficient of expansion between the eyelets and the PCB and they eventually crack the solder joint and fail.

I am fairly certain that if you pull the PCB and resolder every eyelet on both sides of the PCB that there is a good chance it will come back to life. The symptoms you describe are of an intermittent, not a hard failure, and this could very likely be the issue. I do get confused on what turntables have what technology.

On the models that use single sided PCBs, the connectors will wiggle and break the pads from the traces. On those I use epoxy and glue the connectors to the PCB so they are rigid, then use a piece of wire to bridge every trace and repair the cracks. Your turntable will use one of these technologies and those are the failure modes. I’m pretty certain yours uses eyelets.

Hope this helps.

Dave"

Last night I pulled the cover and went at the "eyelets" with my iron. I only did the exposed side. I hooked it back up. Lo & behold, the speeds locked on & held. I will eventual send to some one who can recap it and set it to specs. But nice to see it actually playing consistently.

Did you resoldered all the eyelets by your own? 
This is what Dave adviced me to do too, but i never tried yet.

Anyway you have to run your turntable for some time to check it out. 

Yes I did. There are quite a few on the exposed side. You have to look under the wires. Dave recommends doing both sides and I’ll get to that. I ran it several hrs last night, switching between speeds, the pitch control, stopping & starting. Checked it again this mourning and holding steady.

What he says makes sense. The expansion and contraction of the board & connections. Basically the same as a cold solder joint.