doubt on resistance check

[giampi97]

I' am writing this post because i was doing the final resistance check e it says that terminal 10 should have a 0 resistance with the ground, but how can it be 0 and not 2,49k, since it is connected with the white cable to the upper lug of the headphone jack that is connected to the ground through a 2.49K resistance?
Thanks, Giampietro

 

[Paul Birkeland]

The headphone jacks shorts the 2.49K resistors to ground when no headphones are plugged in.

 

[giampi97]

Ok, then i don't know what is the problem. I have a full built crack (it's the first time i build an amp) and all the resistance and voltage checks are ok. Unfortunately I hear a loud disturbing noise (i tried it in different places, so it is not an external disturb). The strange thing is that if a give a little bump to the amp, the noise disappears for few minutes and then comes again.
Could it be a problem of cold joints?

 

[Paul Birkeland]

Yes, that sounds like a cold joint or a joint that hasn't been soldered at all.  The most common joint that's problematic in the Crack is where the black wires meet at the headphone jack.