Check: Het input and VFO input connections (Dirty, intermittent, missing.)
2. Display reading wrong frequency
Check: If display frequency is reading off by 2 MHz and last four digits on display reading (894.9) check carrier input wire (Dirty, missing, intermittent.)
3. No display or dim display
Check: 5v reg (IC power) not working or plated thru holes not plated thru.
Avobe are common mechanical failures that occur with DG-5. We suggest the following troubleshooting procedure:
Check:
A. Power all power supply levels.
B. Reference oscillator Q21 and divider chain IC5-11 (RF, waveforms, DC.)
C. Carrier, VFO and HET, also counter (When applicable) for RF, Waveforms and DC levels; see service manual for proper levels.
Note: Operation of the circuits are essential before proceeding.
It's been Kenwoods experience that when problems do occur with the DG-5 that approximately 90% of the problems will be caused by insufficient solder connections and not the actual components themselves.
Note: We suggest the following procedure if buffers, mixers and oscillators are working properly: See service manual for proper levels.
Check:
A. All sloder connections (loose or cold.)
B. Solder all plated thru holes: 32 guage wire inserted in plated thru holes takes approximately 30 minutes to do and is very, very, effective.
Service Suggestion:
A heat gun and freeze spray often are very effective in locating cold or not-plated thru holes.
A. Heat board with heat gun (expands board).
This often caused dormant or loose connection to appear.
SB:AR
(c) 2378TKC
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