Akai GX-280DSS Cleaning

[dan schafer]

Hi All
I currently have on my bench a great condition Akai model GX-280DSS open reel, 4 channel tape recorder. The monitor & stereo selector switch are not making too good a contact...like they are dirty. The switches look sealed...is there a way to clean them. Not too easy to access either. Also since I have it opened up, is there anything else I can spot check or clean before I button it back up? I also plan to re-solder the relay board. Anyone's 2 cents is appreciated! Oh by the by...what is the
S. R. T. switch for?
Thanks
Danny in Cleveland

 

[dan schafer]

Hi All,
Well, I re-soldered all of the, maybe 100 rivets on the relay board and inserted bare copper wire into each pass-thru solder rivet hole and re-soldered each one, on both sides....there were alot of them! I was very careful to not bridge solder over to a place it should not go. Hope all of those rivets are supposed to connect to the other side?? So I'm a little frustrated as to why there is a "bad" change. However, now, the dumb thing plays in reverse when the forward button is pressed and the reverse is still dead. When fwd. is pressed it bucks forward, like going into play mode normally, then pauses for a second or two, then plays in reverse. I guess I should have left it alone. The re-wind & fast fwd & stop are fine. I did not heat up any other solder connections and did not pop the covers on the relays to clean. Wish me luck on my next attempt to do so. Too bad for me this belongs to a friend and I goofed it up worse than as it was. Have any suggestions?
Will fine sand paper work as a sub. burnishing tool on those relays or should I just use a blast of good contact cleaner?
Thanks
Dan

 

[JonUrban]

Can any of you "tech guys" help Dan out?

 

[zabble]

...what is the
S. R. T. switch for?

The thread below explains this a bit and has a link for the operation manual which might explain more. Sorry you're having troubles.

http://quadraphonicquad.com/forums/showthread.php?p=29953

 

[The Quadfather]

Yeah, it sounds like you might have either missed something, or you could have shorted something out. Some of the rivets are under components such as relays, and care must be taken when reinstalling components that had to be removed to make sure there were no shorts between relay pins and the new wire. Neat work is important. If all else fails, contact me privately and I'll see what I can do to help.

The Quadfather

 

[dan schafer]

The machine is working fine now. Thanks for all of the kind replies. These machines are the best of the last and probably will be around a long time. After 30+ years the pass-thru solder rivits on the relay board get cracks from alot of expanding & contracting. It's a double sided circuit board and I inserted bare copper wire thru each rivit and soldered both sides. This I hope will be a permanent fix. There were only about 120 of them to do.
Dan

 

[The Quadfather]

Yes, if you do it right, it's a permanent fix. Of course that doesn't account for component failure. Good luck and happy listening!

The Quadfather