Connecting MIDI patch cable DIN connector shielding and pins 1, 5
The middle pin is not pin 3.

(CA-033) MIDI 1.0 Electrical Specification Update [2014] says:


  The cable shall be shielded twisted pair, with the shield connected only to pin 2 at both ends, as illustrated in Figure 3, below.
  
  
  
  Do not connect the MIDI cable shield to the shield barrel of the MIDI plug.
  Cable connection to pins 1 and 3 is not required by this specification, but may be present.