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November 24, 2003
HKLN4216A
5-6
VHF Troubleshooting Tables:
Troubleshooting Table for Transmitter
No EXT MIC audio
1. Mic bias fault
Verify approx 1.8 V dc across EXT
MIC cartridge in TX mode. Verify
audio present (~10 mV rms) when
speaking into mic.
Check Q470. R475, R477,
L471. Check VR473, VR475,
D470 for shorts.
2. Audio path fault
Verify mic audio present (~10 mV
rms) at U451-46.
Verify amplified mic audio present
(~200 mV rms) at U451-40.
Check L471, C470.
Check/replace U451.
3. Defective audio acces-
sory
Try another accessory.
Replace defective accessory.
Table 5-3. Troubleshooting Table for Transmitter (Continued)
Symptom
Possible Causes
Procedure
Corrective Action
Summary of Contents for EP450
Page 31: ...November 24 2003 HKLN4216A 4 8 VHF Theory Of Operation Keypad Notes ...
Page 77: ...November 24 2003 HKLN4216A Notes 7 8 403 440 MHz UHF Theory Of Operation Keypad ...
Page 85: ...November 24 2003 HKLN4216A Notes 8 8 438 470 MHz UHF Theory Of Operation Keypad ...
Page 93: ...November 24 2003 HKLN4216A Notes 9 8 465 495 MHz UHF Theory Of Operation Keypad ...