SACD Player Won't Play Hybrid SACDs

I dropped the SCD-C555ES off at the local Sony authorized repair shop. The place has an excellent reputation and does service work for just about all brands. The problem is the optical assembly. They're waiting for the Sony part to come in. Should be good to go.

Thanks for the info. Some problems have developed in attempting to get my unit repaired. There are now apparently 3 part numbers associated with KHM-230AAA. The original part # was 8-820-132-02. That was replaced by 8-820-132-03. The repair place ordered this part. It arrived, but was defective and was returned and another one ordered. Three weeks have passed and the part has not come in. Apparently, this part has been replaced by 8-820-132-09 and even this may no longer be available.
Is anyone familiar with 8-820-132-09 and is it now the "new" part for the SCD-C555es?

Thanks for the info, Chayro. I wish I knew what it all meant. However, I'm certain the problem is not an alinement or cleaning issue. Over the past few days I have done some "testing." When the player has been turned off and sits over night or is turned off for a while, cools down and turned back on, it plays fine for a while. It correctly reads any combination of SACD and CD disks that are loaded into the changer. However, once the unit is on for period of time (give or take 2 hours), it stops reading SACD and will only read the CD layer. It won't stop reading SACD midstream during a disk play. Once it recognizes SACD, it will play the disk to completion and then stop SACD recognition on subsequent disks.
A few yrs ago, the unit was modified by Matt Anker of SACD Mods. He said the unit would run warm and it was normal. The unit played fine until recently so, I don't think the problem is related to his mod (which had nothing to do with the actual disk layer reading). I tried to locate Matt just to run the issue by him, but he is no where to be found.

One last try. The first replacement part (from Sony) did not work. I purchased 2 replacements from someone in Taiwan that, based on various sites and blogs, is the go-to guy for laser assembly pickup replacements. He gets very favorable ratings and was certain the laser would work for my SACD player and all the ones that used that particular laser. The first one did not work. I'm getting ready to drop off the remaining laser to the repair shop.

There is a "solder blob" that needs to be removed from the assembly for installation. The repair person was well aware of this and properly removed it on each laser. Is there something we are not doing? It seems a bit crazy that none of the replacement lasers work.

The reasons I want to hang onto this player are because a few years ago I had about $800 worth of mods done by Matthew Anker of SACD-Mods, it's a solid well built unit and it is an SACD changer. The player sounds great when it works and there ain't no more SACD changers being made. I like the convenience of a changer so, I want to try and save it.
The individual that I bought the laser assemblies from is going to replace them. This for sure will be my last try.