2508 when DSD depressed, brakes did not release. To rectify ~~~~~ Checked DSD switch contact ok. checked HEMR LGD2 0VDC ok, no floating voltage. Checked HEAR relay ok. Swapped #2508 HEAR with #2507 HEAR to no avail. Changed out HEMR to no avail. ops20 to follow up. Done by: Jack/Koh/Rizman/Sanip 15.4.24 To Further check  When 2508 hostler DSD was depressed, brakes were unable to be released. Found HEMR unable to energize when hostler set to FWD/REV. Checked Line 7080 and EBR1 ok.  Measure the HEAR relay base front and back 0.2ohm~0.4ohm. Found Line 7081 had no voltage and thus unable to energise HEMR. Measured line 7081  between 1508 and 3508 underframe junction box OL. Uncoupled semi permanent coupler between 1508 and 3508 and serviced the electrical pins. Coupled back and measured line 7081 ok 0.2ohm. Function checked DSD able to release brakes and HEMR energized. Performed coupling / uncoupling operation and function tested 3-car limited movement satis. Done by Saini/Asruddin/morgan 45427