Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: sjeffrey on October 05, 2013, 11:37:18 AM

Title: Input tube not wokring and no LEDs [SOLVED]
Post by: sjeffrey on October 05, 2013, 11:37:18 AM

I just finished assembling my Crack and going through the resistance tests
all of them are right on except the center pin which I assume is the input tube center pin.  If so resistance goes to 0 and not 90-100k.

I check all solders and circuit and everything looks correct.
I hesitate to continue until I get confirmation or some hint on what could be wrong.

thanks,
Steph

Title: Re: center pin resistance test
Post by: sjeffrey on October 05, 2013, 11:50:50 AM

Looks like center pin is RCA center pin which reads 100k
I had searched before but was searching for LED and resistance  so got nothing that helped.

voltage test is next. Hopefully nothing bad happens to me.  :o

Title: Re: center pin resistance test
Post by: Paul Birkeland on October 05, 2013, 11:59:03 AM

Yes, the center pin is the center pin of the RCA jack.

The LED may or may not give you a resistance reading, which may or may not depend on the orientation of your meter leads ;)

Title: Re: center pin resistance test
Post by: sjeffrey on October 05, 2013, 02:47:14 PM

So I did voltage check and all the ones that should be 90V are 140V.  Also the LEDs don't light up. 

Searching forum but haven't found anything yet.

EDIT: voltage at A3 and a8 is 0v.  Input tube is not glowing.  I was too excited about the output tube glowing I didnt notice the input one wasnt at first.

Title: Re: Input tube not wokring and no LEDs
Post by: sjeffrey on October 05, 2013, 04:23:49 PM

Well I reheated all solders and this time tube and leds light up.  Voltage was correct as well.
Flipped it over to do sound test and tube went out again.  Looks like I have a cold solder somewhere :(

Title: Re: Input tube not wokring and no LEDs
Post by: sjeffrey on October 05, 2013, 04:48:34 PM

So it was A9 that was not soldered correctly.  Fixed the connection and all good now  ;D
Listening with iTouch now just to test it out and sounds great already.  Can't wait to plug it in my Bifrost.

Next up is a bit of tube rolling and then Speedball :)