Galaxy DX99V Frequency Counter shows 24.xxx

[Derrick Walls]

I'm working on a galaxy dx99v and the frequency counter show 24.xxx and doe not change by switching the band switch. I have tried frequency board and 10.240 crystal. checked for cold solder joints and found none. Voltage at TP2 not present. Guys if you have any ideas please share. At this point I'm stumped....

 

[Robb]

http://www.cbtricks.com/cgi-bin/database/galaxy_db.cgi

 

[Derrick Walls]

Went there first had no luck..

 

[Robb]

Does your radio receive and transmit?

 

[Robb]

Replace diode D36 located on the frequency band board. Diode D36 is a 1N4148 and should be replaced with a 1N4000 series such as 1N4003 for better stability.

Symptom Constantly blows out the 10.240MHz
Cure Replace C82

Symptom No TX and no RX, frequency counter displays 24.XXXMHz
Cure Replace 10.240MHz crystal

Symptom On Models with frequency counters, Frequency display reads 24.xxxmhz and radio has no RX or TX.
Cure Replace X1 the 10.240mhz crystal. Sometimes the leads of the crystal just need to be resoldered on the pc board.

 

[Derrick Walls]

doesn't recieve or transmit. replaced 10.240 crystal still cant get reference signal at the pll chip

 

[Derrick Walls]

replaced c82 and replaced diode on the frequency board with the 1n4003. no change with either of these

 

[Robb]

As a guess, either the PLL isn't getting voltage feed from the regulator; or the PLL itself is fried. I'd check the voltage regulator for proper output.

The 10.240 reference osc is a very simple circuit with nothing that can go wrong there (other than xtal itself, or a bad solder joint), so I doubt that is the problem.

 

[Derrick Walls]

I wondered if it were the pll chip but was hesitant to replace it. I'll check for voltage. Let you know how I turn out

 

[Robb]

It still might not be fried. Remember, that if the ins and outs of the PLL are open, the chain is broken and nothing between the PLL, VCO, or loop osc is going to read correctly. But you still should be able to see the ref osc output making freq. Better to make sure that everything is intact and locking.

The 4 bit chips can also fail and leave the pll unlocked. You have your work cut out for you. Been there . . .

Let us know how you do.

 

[sonoma]

have you checked for bad caps or resisters in line with the PLL and the 10.240 crystal. a few years ago I had one do this and it had a bad cap shorted to ground and killed the 10.240 freq . in fact Ray was still with Galaxy when I had the problem. that tells you how long ago it has been , about 8 or 9 years. Ray had me to pull legs of a cap one at a time to find the problem. just look at the schematic for parts in line with the 10.240 crystal and leg 3 of ic5.

 

[Derrick Walls]

Turned out to be a fried pll chip. put a new one in and back to business as usual. thanks guys I appreciated the help.

Lucky in MS

 

[Gunner357]

OLD post but Mines has similar issue except its starts working after its on for 10 or 20 minutes Had it to a shop 2 times says its fixed but always comes back...... Is this a classic sign of a bad solder joint?

 

[Harley3315]

OLD post but Mines has similar issue except its starts working after its on for 10 or 20 minutes Had it to a shop 2 times says its fixed but always comes back...... Is this a classic sign of a bad solder joint?

I have one doing this randomly then it will work fine again for a while
It seems to be unlocking for sure not just the counter rolling cause if someone is in the middle of talking they are just instantly gone. Any ideas or just start with the crystal?

 

[Jim5570091]

I have been following this for several days. Mine will be fine, receive and transmit. Then it will jump directly to 24.xxx. Sometimes it will just begin to drift down to 24.xxx. 99% of the time I can bump it on the bottom of the case and it will jump right back in frequency lock. Can a bad crystal cause the symptoms? Or for sure a bad solder joint? I can also just leave it on and it will come back on its own.