Midi in not working

[pwdm]

 Hi there Midi folks

I,m just half way throught my first midibox and have got stuck on getting the midi in to work.

 Have run throught the fault finding and have come up with the following results.The problem i have is i,m a bit confused to what the problem  is.

   *  Check the resistor values at the MIDI In Port: R11=220 Ohm (resistor code: red-red-brown), R6=1.2kOhm (brown-red-red), R5=5.6kOhm (Green-Blue-Red). ok

   * 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.

     Note:so long as the LED is connected directly to the Rx pin, the PIC will *not* receive the MIDI data due to the power consumption of the LED. This method is only usefull to test if the MIDI signal is available at the Rx pin   FAIL

   * if the LED doesn't lit, connect the anode to the optocoupler (Pin IC2:6). FAIL

If it still doesn't lit, connect the anode with the +5V rail of the optocoupler (Pin IC2:8 ) PASS

   * If this doesn't help you to detect the error, continue with the next step - 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. If the LED doesn't lit, check the polarity of the protection diode D1 before the optocoupler (again...). Also check the polarity of the MIDI cable (again...).PASS

   * Standalone test for the optocoupler: mbhp_core_extract_opto_test.gif  PASS

   * A second standalone test for the optocoupler, this time the optocoupler isn't plugged in the core module: mbhp_core_opto_test.gif  NOT DONE

   * 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. Send any SysEx dump by using the "Send/Receive SysEx" function of MIDI-Ox. The number of sent bytes must match with the number of received bytes.  FAIL

Thanks in advance

[illogik]

just to be sure, you have checked your board/soldering?

a lot of problems i encountered were "only" badly soldered contacts;

just look with your multimeter for "open" contacts.

[pay_c]

Also two often errors:

- Is there really MIDI coming out of the comp? Can you check that? (e.g. with some synth or so) There are often some lame Midi Interfaces (most often gameports or so) that do not send MIDI cause of some tiny prob with your software.

- Is the optocoupler OK? If you have put it in the wrong way *once* it´s fried. To go for sure, replace it (and put it in the right way! Opposite to the PIC).

Also always some good option: The LTC. The Midi In LED is always some kinda practicable.

Greetz & good luck!

[pwdm]

Hey Many thanks for the reply,s.

 Have already checked the board over for any shorts and the midi out on my card works fine with other outboard stuff

 May have put the octocoupler in wrong at some point so will order a new one shortly..

Again many thanks to all concerned with the midibox.

[pay_c]

Errrrr.... don´t order one....

two, three.... what the heck ... you´ll use them *someday*(and the price is really no point)  ;)

[pwdm]

LOL

 Sounds like a damn good idea thanks for the good advice.

May as well get 2 or 3. :)

[pay_c]

;D ;)

[pwdm]

Hey folks

Just noticed its a year since I last posted this, and guess what? Still not got it working

Took the board apart and rebuilt,replaced the octocoupler and had the father-in-law check for shorts . Still cant get the thing to recieve midi in..

So was wandering if anyone here would have a look at my board, for a fee of course. Just want to get my midibox working.

I,m in Denmark if anyone is intrested so its easy for me to post to europe.

Heres hoping

Thanks

[pwx]

Hi,...

perhaps you can post a few photos....... so we all can have a look :o ;)

Greets,

pwx