Why no stereo?

Please excuse my essential newbieness here (know thyself, some smart old-timey guy said).

I own an early-1970s vintage (I think) Packard-Bell solid state console hi-fi with a Garrard Model 3500 turntable. I bought it (60 bucks) from the original owner the better part of a year ago. The cabinet is quite stylish, and the workings were just fine, too, until a couple-three months back, when the phonograph started playing through speakers on both sides only when in the mono mode. In stereo, it plays only through the speakers on the right (the right as you face it). The old-timer I bought it from said he had replaced the needle recently, if that provides a clue. But again, it worked fine for the first several months I owned it.

My question of you kind and patient ladies and gents is where I might start my troubleshooting. I dig this thing quite a bit, and since I purchased it I've procured numerous old LPs, and friends bring me more all the time. I'd like to enjoy them in all their true stereophonic glory.

Any tips would be deeply appreciated.

Glinda,
This could be somewhat of a problem to track down--
Does it have a stereo radio function ? If yes, does the radio operate OK ? If so, I would look at the cartridge connections and/or the stereo-mono switch itself. I doubt a needle would cause this. If no, it's going to require someone with at least some meters to determine what has failed. Ron Rich

Thanks, Mr. Rich.
Yes, the radio does indeed work in stereo mode, on both sides.

How best to check the cartridge connections? (Again, I'm a newb.)

Not knowing the model/chassis numbers and not having a schematic, it could be several things wrong.
It's really impossible to diagnose such things over the intenet.

Glinda,
Unless you wish to invest in some schooling and test equipment, I would suggest that you should find a pro to look at it. Had you entered your location in your profile, a pro maybe close by--or someone may have a suggestion as to where to find one.
Barring the above, all you can do is look at the cartridge, and see if maybe a wire has been un-plugged-- Ron Rich

On that particular unit, I can think of only the following possibilities:

Bad cartridge
Loose cartridge wire
Shorted tonearm wiring
Open tonearm wiring
Muting switch
Unplugged cable to amp
Selector switch

Unfortunately, on mine, it's the selector switch.

Thanks, gents.

I'd have a pro deal with it, but it's a big ol' console, and a heavy one at that, so it might involve having that pro come to it, rather than the other way around, and that might run into real money.

C'est la vie, eh? Can't take it with you, etc.

Lift the tonearm and makesure none of the tiny little wires broke free from its solder at the back of the cartridge. If not run your turntable, gently wiggle the needle around with your finger as it rests on the rubber holder. if you hear the dead speaker crackling there is a short in the cartridge. needs replaced.if not i would start looking underneath the turntable where all the wires splise into your rc outs. look for broken wires, bad connections.