Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: Shamsyrup on August 23, 2019, 11:13:22 AM

Title: Led not lighting up and voltage irregularities (Resolved )
Post by: Shamsyrup on August 23, 2019, 11:13:22 AM

Hi, I have fully assembled the crack 1.1 amp kit. The LED which is connected to the A8 and center pin is not glowing at all. I have double checked the orientation and soldering joints. Other LED is glowing fine. There's a very loud hum coming out when I connect a set of testing headphones.
Resistance measurements checks out perfectly fine with the manual but my voltage measurements are way off

1. 5.62V
2. 198V
3. 0V
4. 201V
5. 92V
6. 0V
7. 65V
8. 0V
9. 120V
10. 0V


A5 and A6 were arcing because of a solder blob

Title: Re: Led not lighting up and voltage irregularities
Post by: Paul Birkeland on August 23, 2019, 11:17:05 AM

The wire that leaves terminal 1 goes up to B1, how does that connection look?  If it went, for example, to B8 or B7 on accident, you'd get the problem you're having.  What happens to the voltage at terminal 1 if you run the amp without a 6080 (which won't do any harm).

-PB

PS - it is almost a certainty that there was never anything wrong with the LED.

Title: Re: Led not lighting up and voltage irregularities
Post by: Shamsyrup on August 23, 2019, 11:52:12 AM

Checked them. They look fine. Without the 6080 the voltage reading is almost same at 5.2V

Title: Re: Led not lighting up and voltage irregularities
Post by: Shamsyrup on August 23, 2019, 11:56:01 AM

imgur(.)com/gallery/nvTTsfg

Here are some pictures. Unfortunately having issues attaching pictures over here

Title: Re: Led not lighting up and voltage irregularities
Post by: Paul Birkeland on August 23, 2019, 11:58:36 AM

What is the yellow sludge that's all over everything?

Title: Re: Led not lighting up and voltage irregularities
Post by: Shamsyrup on August 23, 2019, 09:48:20 PM

That is flux paste.

Title: Re: Led not lighting up and voltage irregularities (Resolved )
Post by: Shamsyrup on August 23, 2019, 10:49:02 PM

Thank you so much for help. Both LEDs are lighting up now. A6 and A5 were arcing as there were some residual solders

Title: Re: Led not lighting up and voltage irregularities (Resolved )
Post by: Paul Birkeland on August 24, 2019, 05:26:40 AM

Can you provide a part number for the flux paste?  Adding this is completely unnecessary and if it's not the correct flux, it will ruin your kit pretty quickly.