Ambika voicecard stops working and then works again

ok I have a voicecard which is driving me crazy.
It seems to stop working when I change the multi (even if all the multi I’m using share the same settings and voices allocation).

Trying to reflash the voicecard with the VOICE$.BIN file seems to do nothing and on the firmware upgrade menu page I get “port 3 device ?”.

After a while the voicecard start working again but I can’t understand what is causing the issue in the first place and why it starts working again out of nowhere.

I also noticed that the led and note status on that voicecard seem to stay light up, even if the synth is not receiving any midi note.

Please help me understand if the issue is software or hardware related. I cant use the synth with some random burst of noise periodically coming out of it ;(

Looks like a bad connection between the motherboard and the voicecard!

i’m going to check the assembly instruction then. Thanks a lot for the help.
It’s really strange because I’ve been using the synth for a couple of hours now and this time is working perfectly…