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[QCX] Pulled Q2, now Q1 gets hot immediately


Jess Gypin
 

So I desoldered Q2. Looked it all over again and applied a couple of seconds of power at 12V from bench supply. Now Q1 gets warm right away. Don't let them get hot enough to let the smoke out. Always have my finger on them. WTF? Still looking.


 

So I desoldered Q2. Looked it all over again and applied a couple of seconds of power at 12V from bench supply. Now Q1 gets warm right away. Don't let them get hot enough to let the smoke out. Always have my finger on them. WTF?
Jess,

As others have said, this will not happen if unless Q6 (or something else) is faulty. Replace that, maybe Q1 2 3 are serviceable.

73 Alan G4ZFQ


Jess Gypin
 

Did I miss an email somewhere? I don't remember anyone mentioning Q6. As I said, maybe I have a bit of tunnel vision because almost all of not all of the problems I have had with builds in the passed have been misplaced parts, poor solder joints, cold solder joints or solder bridges. I am spoiled because 90+% of the kits I build work at first power up as I am really careful during the build. Just have to make up my mind that this old dog can learn new tricks. Sorry if I am taking up too much bandwidth but I personally enjoy following others journey with kit builds and success and fixes. But I should not assume.........?

Jess AE0CW

On December 20, 2017, at 9:00 AM, Alan G4ZFQ <alan4alan@...> wrote:

So I desoldered Q2. Looked it all over again and applied a couple of seconds of power at 12V from bench supply. Now Q1 gets warm right away. Don't let them get hot enough to let the smoke out. Always have my finger on them. WTF?
Jess,

As others have said, this will not happen if unless Q6 (or something
else) is faulty. Replace that, maybe Q1 2 3 are serviceable.

73 Alan G4ZFQ


 

Did I miss an email somewhere?
Jes,

I'm getting confused, you've changed the subject now I'm lost...

I don't remember anyone mentioning Q6.

Ah! this, I said

Nothing on the display seems to indicate there is a short on the 12V
line stopping any 5V. This could be due to a faulty Q6 and a fault in one or more of Q1, 2, 3.

Maybe just a faulty Q6

73 Alan G4ZFQ