Korg Poly800/EX800 Users

Hello all,

I am facing a strange problem with my EX800. I have the SYX file for factory (and also some SYX files I made after sending a dump request to the EX800 - note that it is a non-modded one, still original hardware)

When I send the SYX file to the EX800, the synth clearly receives it (the display goes blank while it receives the MIDI data). I get no message back from the EX800 then (it seems correct because if I change the checksum, the EX800 reports a dump error after receiving the file)

Here is what I see : if I edit a parameter (let's say param 18, set to 2 originally) and I reload the SYX file, the EX800 is clearly ignoring the SYSEX. The data I see in the changed parameters are still the same than BEFORE uploading the SYX file. It looks like the synth is ignoring simply the valid SYSEX data. If I reload the data from cassette interface, it works (the parameters I have changed are restored to original value)

Is there something special to send to the synth *before* sending the data dump (to tell him "I will now send you the RAM dump") ?

I am working on this problem since 2 weeks, and I am simply getting crazy. I can't understand why the EX800 does not take into account the SYX data he has just sent before

Is there a change between a dump going to the synth and a dump coming from the synth ?

Thank you by advance for your help

Benoit