hey there
i am pulling my hair out at this! haha
i had been blaming my soundcard, so i went out and bought a midiman usb -> midi device. and i’m getting the same problem with being able to send but not receive.
the core is on its own with only the midi sockets and psu connected.
i am getting the 2 second requests for mios no problems in midiox
i have completed all the troubleshooting methods, the main ones are described below:
solder two cables to the bottom side of the core module like shown in mbhp_core_midiin_debug.gif. The LED should lit (take the polarity of the LED into account, the short leg is the cathode and has to be connected via a resistor to Vss). So long as single MIDI events are received, you won’t notice a difference, but with a continuous SysEx stream the LED should begin to flicker.
- led lights but does not flicker when i send a large sysex chunk, is this strange?
see mbhp_core_midiin_debug2.gif - in this configuration the LED should only lit when MIDI data is received. Than more MIDI events are received a time, than brigther the LED.
- the led does flash when the sysex chunk is sent
final check to ensure that all 4 MIDI ports are working: put the PIC out of the socket and loopback the MIDI IO ports at the Rx/Tx pins like demonstrated in mbhp_core_extract_io_loopback.gif.
- this works fine
it seems strange that all the tests seem to work except the one not flickering!
any help or advice on this would be excellent and greatly appreciated! 
cheers and thanks in advance,
Rowan Hall