Shure PG4 - Page 26

26
25A1104 (Rev.1)
Fails/Weak Audio at TPBAL2/TPBAL3
1.) Confirm audio at TPE
2.) Confirm 4.5VDC at TP_Vref
3.) Confirm tone key in RF signal or R280 is shorted to disable TK
4.) Check and confirm values of C144, C150, R150, R153
5.) Check other components in vicinity
Fails Tone Key at TP_TK
1.) Confirm 4.5VDC at IC232 pins 1,5, and 7.
2.) Check RF signal for 32.768kHz tone key frequency
3.) Check RF signal for -20dBc tone key level
4.) Check placement of and values of C277, C278, R278, R279, R295, and R296
5.) TP_TK should measure > 0.5VDC with tone key present in RF signal