dead cartridge? Darn the Luck ! ! !


Old OM20 that I haven't touched in 20 years. Tried it direct thru my Onkyos phono pre. Nada.Then I tried an outboard NAD pre. Left only.
I swapped sides. Right only. Pre is OK.
I reseated the cartridge wires at the headshell, both sides, 4 pins.
Tested continuity from the cartridge wire through to the NAD input. All 4 pins good.
I know it's rare, but is there something I forgot? Seems I have a dead right side.
metropical
I managed to get both sides working, however they are out of phase.I know the speakers are wired right as I ref’d rcvr/tuner and TV.Here's a link to a photo of the shell if anyone has an idea which wire to flip, though I thought I tried all combos.
https://farm5.staticflickr.com/4886/31993170238_868623648e.jpg
It doesn’t matter which channel you switch the phasing on. Left or right, choose one only and enjoy. 
Buy yourself a test record like Hi-Fi News Test LP to make sure your system works fine, you can check everything with this test LP (and there is a free protractor inside)
I had a new Ortofon Winfield that was internally wired wrong.....they readily exchanged it, ....stuff happens
this is way too old for warranty and it worked fine when last I used it ..... 20 year ago.
I’ve tried every which way to flip phase. Nothing changes it. But I’m not sure which way the head shell is configured. I just assumed logically, left and right, but perhaps it’s crossed like the Ortofon.https://farm5.staticflickr.com/4861/30936942687_5989ca5d33.jpg
Kind of thinking now that lack of use, aging, whatever has messed it up inside.
Don’t think I’m dropping $50 for a test record. This is not my old 24 track Ampex 1200.
I tested another source thru the pre, the pre is fine.
it’s either me crossing wires or the cart failed with age.
From Ortofon tech supp:
"There are two possible reasons for channel missing or level differences:  the incorrect position (rotation - in front view) of your cartridge in the tone arm. The other is a defect in the cartridge itself caused by aging, rotation of the armature or shunt(s) between the turns of one coil. "