Korg M1R card readers not working

My Korg M1R won’t read external expansion cards (Synth1, 2, brass, organ, etc.). I replaced the card switch because toggling the original card switch resulted in getting to the expansion card settings maybe 1 out of 100 times. No joy after replacing the tactile switch though. Also, trying to load program settings to or from a RAM card resulted in card not found error.

Both CN14A and CN28A jumpers from the motherboard to both card readers are putting out 5 volts, so that’s a good sign.

The last step I tried was removing the readers and spraying deoxit on the contacts. I’m not optimistic that will work because a visual inspection didn’t show any bent pins or corrosion. The unit looks to be in good shape.

Any ideas? Or does anyone have any spare Korg KLM-1304 or 1305 memory card boards they would like to part with? Or know any sources? I’ve struck out on google and ebay.