Repair Tricks; Front End Protection Diodes; Common Faults - Ranger RCI-2950 Service Manual

These diodes go out when the radio is subject to an extremly strong input signal. If the radio doesn't recieve or quits
recieving after you unkey, check D21 & D22. These ones are 1N914 or 1N4148. They cost very few.
: Need Help.. My Galaxy's receive is almost gone! I still get some rec. but it's fading.
: It worked fine until a nearby radio keyed and then?
: Any sugestions?
On the RCI 2950 you would need to check D21 & D22. On the Galaxy Saturn after comparing the two schematics it
appears to be D33 and possibly R263 and R142. I would check these for any burning or for function.
Frequency selection doesn't work properly. Locate R611 which is a 47 Ko resistor located on the vertical CPU board on
trace side. Change out with a 10 K quater watt resistor.
Older 2950's with batter backup will discarge the battery if the power source is removed and the radio is left in the "ON"
position. This causes corruption in the memory circuits and in the microprocessor. This can cause the failure to turn on....
lights on... and nothing else.
Also found other faults:
· The 8 volt regulator that is on the left side of the radio (speaker side up, front closest to you) the regulator
favors the front of the radio....anyhow... I have seen 3 or 4 radios that had the turn on with no receive or
transmit. The cause: cold solder joint on the regulator, this could be caused by the stressing of the chassis
during mobile installation or dropping, bumping of the radio. The cure: remove old solder from regulator and
resolder. Don't attempt to remove the regulator from the chassis, it's attached there for a reason... heatsink....
One other fault:
· Warbaling on ssb.... Be sure to use the proper power cord that came with the radio... don't use the radio shack
substitution. The wire guage is smaller and thus won't be able to pass enough current thru the wires. This
causes the warbaling effect on ssb. Also try turning down the mic gain on ssb when running a power mic.
· Wire the radio backwards (reverse polarity) usually causes the power regulator for AM to short out. This will
give the radio a 40 Watt carrier with no modulation. This is not to be done intentionally.... just letting you know
what the radio is able to do without power control.

REPAIR TRICKS

FRONT END PROTECTION DIODES

FREQUENCY SELECTION

COMMON FAULTS

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