My Kawai K1 died... kind of. It lost all internal presets and after some googling I made the conclusion that the battery was depleted. What to do? Replace it of course though it wasn't exactly like replacing a CMOS battery. The original is soldered directly to the motherboard but luckily the pins has the same distance as some battery holders. I desoldered the old one and replaced it with a holder and a brand new battery.

The good news is that I didn't screw up things and all works and that Kawai still provides the original presets and some more on their web site. I'm also able to transmit sysex data to the K1 with an exception -and here's the bad news- single presets "ID8" and "iD8" are not received. I have tried different settings in both Bome's Send SX and MIDI-OX but still no luck. Are there other Kawai K1 users that can explain how to get those last presets transmitted to the synth?

It might be that some memory by randomness got a bit set it to locked location or something - preventing it receiving new data.

I haven't had Kawai but Kurzweil in the same situation.

They had factory reset of everything that also cleared memory for own presets.
There were also some testing procedures you could start checking everything up.

Look in manual for that maybe.

Oh, I read the manual alright but found nothing. I even tried Atari software but no luck. Then - and I don't know why - I thought that maybe I could try to connect a cable to the MIDI out port as well on the K1. For some reason that solved the problem so now my old Kawai K1 is as it used to be.

I forgot to mention that when I opened it I found some rust, dust and a mummified fly. God knows how and why it got inside my synth

That makes sense. What you were using to dump the sysex was probably looking for a handshake before it sent the final F7 at the end.

ew