Re: No output QCX 40 output drains show 1.6 watts in receive

George Korper
 

Alan,  I checked pin 3 again and it is still showing 5 volts. which I see shouldn't be 5 but zero.
The transmit voltages are not changed but the same as receive.


On Tue, Dec 10, 2019 at 5:30 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
I sent you receive voltages. Thanks for the link, I forgot to reread the trouble shooting section.
There was no change in voltages in transmit, so
I can see the 12 Volts is not on the pins in transmit.
In transmit nothing on the IC3 changes.


On Tue, Dec 10, 2019 at 4:59 PM George Korper via Groups.Io <georgekorper=gmail.com@groups.io> wrote:
IC3 Voltages LCD unplugged:
some values rounded off.
1) 5
2) 5
3) 5
4) .02
5) .01
6) 5
7) 0
8) 5
9) 0
10) 0
 11) 0
12) 5
13) 5
14) 5

On Tue, Dec 10, 2019 at 4:31 PM Alan G4ZFQ <alan4alan@...> wrote:
> I went ahead and replaced Q6. No change.

George,

Replacing things blindly may not work. It is not unusual for several
components to blow in the PA, replacing one component may blow it again.
Voltage readings are important. Also check voltages after you remove a
suspect but before you renew it.

> I will try to get voltages on IC3, but I didn't see the voltages listed
> in the list, are they somewhere else?

http://www.qrp-labs.com/qcx/qcxtrouble.html#transmit
> May I remove the LCD do get to to IC3 and still take the voltages?
Yes

> The QCX was running fine.......

Quite a story:-) Settle down do it slowly. Measure voltages, remove
anything suspect, measure voltages.. Report here.

73 Alan G4ZFQ



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