Help! My crack shocked me! - solved

[kscwuzhere]

Hey so I have a Bottlehead Crack that was working for a good week or two when all of a sudden the chassis shocked me! I immediately unplugged and flipped it over and made sure that all my connections looked clean and re-tested. This time the chassis didn't shock me but when i tried unplugging the headphones (which were on a gold plated 1/4" adapter), that shocked me. I rechecked all my connections again and decided to do a resistance/voltage check. After successfully testing the resistances I moved on to the voltage check and everything went well until I put the positive lead on terminal 15, where all of a sudden the crack sparked at that terminal and the tubes immediately stopped glowing. The LEDs on terminal A3 and A8 also weren't lit anymore. Upon recollection I may have touched the positive lead to the right power switch terminal (but im not totally sure). What should I do?

[Paul Birkeland]

You blew your fuse, I'd get a replacement.

The screw by the #8 screw at the power inlet is your safety ground, it prevents things like this from happening. Just out of curiosity, how old is the wiring in your house?

(also, how shaggy is your carpet?)

[kscwuzhere]

I removed the fuse and it seems to be intact. The carpet isn't too shabby and I'd say the wiring in the apartment is definitely not older than 50 years old.

[Grainger49]

Measure the the resistance of the fuse.  I have seen blown fuses that looked good.

Are your outlets grounded?  Have you tested to see that the outlet is, indeed, grounded.  There are testers that will tell you if the ground is intact.  I pictured one in a thread named, "Pictures Of Tools" in the Tech Tools folder.

And finally, check the ground circuit resistance as in the sticky in the Crack folder.

[kscwuzhere]

So I got around to replacing the fuse and redid the resistance/voltage checks with success! The tubes are glowing and they sound great. There still is a slight issue though, when I insert my headphones into the crack I hear unsettling popping sounds which stop when it's fully inserted in. Any idea what the issue could be?

[Grainger49]

First question, is your power in your house grounded? 

Second question if you said "Yes" to the first, did you check it?  There is a tool in my thread "Pictures of Tools" in the Tech Tools folder of a proper tester.

Finally, have you tested the ground path?  If not there is a sticky in the Crack folder that verifies the ground path.

[kscwuzhere]

So I did the ground check and the following terminals did not give a reading:

volume control - two terminals on the far right (top and bottom)
RCA red and white wire 
headphone jack red and white
center lug 9 pi
terminal 4

I re-soldered these terminals and now, they all give readings (the ports that are connected to the white and red wires on the headphone jack gave a very high reading compared to the other grounding spots) but I still hear that extremely loud popping sound when I plug in headphones to the crack. What should I try next? Thank you!

[Grainger49]

Are you still trying to find out why you were shocked?  The only terminal you call out that should be grounded is the center lug of the 9 pin socket.  The ground is on the left most terminals on the volume control, the right ones should be soldered to the red and white wires to the center of the RCA Jacks.  Those are not grounded, it would short out your inputs.

Did you use this thread?

http://www.bottlehead.com/smf/index.php/topic,4812.0.html

That is step by step tracing the ground path of the Crack.

Do you have grounded outlets?  Did you check to verify that your outlet is actually grounded with the tool I referred to above?

[kscwuzhere]

The crack no longer shocks me, I'm just trying to get rid of the extremely loud popping sound I hear when I plug in my headphones to the crack. I re-checked that crack grounding thread you linked at it seems as if some of my connections on the ground path were not soldered cleany; these being bottom right lug on the headphone port as well as the ground connections on terminal 14. So I re-soldered everything and the crack seems to be functioning perfectly! No more popping sounds, no more ground issues, no more getting shocked! Thank you so much!

[Grainger49]

You are welcome!