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AT-100PROii front panel dont work

 

Hi

I have 5 LDG AT-100PROii who have the same problem, non of the buttons works on the front, you cant change antenna and so on, is it the CPU who is bad ? but all of them tunes automatically when apply RF, LED is working.

73
Lars
SM2UHF
 

Hi Lars i just looked at the diagram in the files section, and it does work the same as the at-600 that i have fixed , there was as short
from pin 1, U1 going to the PIC CPU, pin 40, that is the tune switch input , so like i said i cut the track at the pin 1 U1, Then all of the buttons work as they should,, but yours could just be a bad switch, stuck on, but test u1, pin 1 see if it is going to ground, i think that there was about 50ohms from pin 1 U1 to 0V Ground,
Thanks Dave 2E0DMB
 

Hi Lars,
I think I can help you on this one,
I got a AT-600 PRO 11 with this problem, and I have now fixed?it, it was not the CPU, it was a small 5pin comparator that it uses for the remote switching from the back panel,what was happening is that the comparator was making it look to the CPU that the tune switch was on all of the time so that when you turn the? tuner on it will not do anything
Each switch has a 5v supply going to it using a 10k ohm resistor, so when you push a switch that line is sent to ground 0V,? so with the tuner? switched on , test each switch for the 5V ,you may find that the tune one will not have 5V as it is being pulled to 0V Ground, or it could be any of the switches gone bad, but I would test the tune one before testing the others,
I then ,cut the track going to the pic CPU pin,? to the comparator, and all worked fine, so then I got a new and comparator, and changed it,?
Then fixed the track I cut,?
Now it is working fine,
This was with a at-600pro2 but your switching may work the same,
Please let me know how you get on with it,
Thanks Dave 2E0DMB
 

Hi Lars,
I think I can help you on this one,
I got a AT-600 PRO 11 with this problem, and I have now fixed?it, it was not the CPU, it was a small 5pin comparator that it uses for the remote switching from the back panel,what was happening is that the comparator was making it look to the CPU that the tune switch was on all of the time so that when you turn the? tuner on it will not do anything
Each switch has a 5v supply going to it using a 10k ohm resistor, so when you push a switch that line is sent to ground 0V,? so with the tuner? switched on , test each switch for the 5V ,you may find that the tune one will not have 5V as it is being pulled to 0V Ground, or it could be any of the switches gone bad, but I would test the tune one before testing the others,
I then ,cut the track going to the pic CPU pin,? to the comparator, and all worked fine, so then I got a new and comparator, and changed it,?
Then fixed the track I cut,?
Now it is working fine,
This was with a at-600pro2 but your switching may work the same,
Please let me know how you get on with it,
Thanks Dave 2E0DMB

On Wed, 27 Apr 2022, 18:48 Lars H Flygare, <lars@...> wrote:
Hi

I have 5 LDG AT-100PROii who have the same problem, non of the buttons works on the front, you cant change antenna and so on, is it the CPU who is bad ? but all of them tunes automatically when apply RF, LED is working.

73
Lars
SM2UHF

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