Wadia S7i not reading the contents of certain discs

Have exactly the same problem with Wadia 781i, I complained about it here: CD Error Correction.  Spent these last months trying to comprehend the glitch, the first part of my efforts is posted here:
 Wadia 781
As promised here, Part Two is coming up, with vibration graphs/numbers for different CDs.
In short, badly pressed or warped CDs which should not be even played, Wadia wouldn't play. A few (presumably) watermarked CDs it won't play either.
I have dozens of ECM CDs, but only one is not playable by 781 (Shumann, ECM2396). Have no explanation for this, had to make a CDR copy which plays perfectly.

Steve Huntley said that his Cantata Music Center 3.0 bests his efforts for Wadia. Haven't listened to it yet

thanks so much - I just burned a cd-r and it plays perfectly.  It's a relief to know that the laser mechanism is not at fault, which would mean another trek back to Audio Research, which replaced the transport about a year ago.

-john

@sevs,

Holy cow! Steve Huntley is now working for Resolution Audio alongside Jeff Kalt? I did not know that. That would be a sort of Dream Team for the Digital Music Reproduction Field. I would love to hear the Cantata Music Center 3.0, but I'm sure it's out of my price range. I did own a Resolution Audio Opus 21 a few years ago and I thought it was a great CD player.

I would never use a cd player that wouldn't play all my discs.

This apparently is the complete Sony DVD rom drive/laser used in the S7i, if you can find the model no. on your own one and search eBay, it very possible you could get it at least half or even quarter that price.
https://www.aliexpress.com/item/New-Mechanism-Laser-Len-For-WADIA-S7i-Optical-Pickup/32830680576.htm...

Cheers George