Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: KcMsterpce on September 25, 2014, 03:22:00 AM

Title: Terminal 7 at 140v and no right channel
Post by: KcMsterpce on September 25, 2014, 03:22:00 AM
As the topic indicates.
Voltages are all within spec except for terminal 7.
All the LEDs light up, but two turn off after about one minute on the Speedball PCB w/heatsinks.

I was a little concerned about the ground at B+ on the large PCB. Looks like the solder is touching the red wires together near the resistor.

Pictures attached.

Sorry they aren't spectacular photos. Someone is borrowing my camera with the macro lens.

http://imgur.com/a/A5rbN#0
Title: Re: Terminal 7 at 140v and no right channel
Post by: fullheadofnothing on September 25, 2014, 05:28:11 AM
Did your crack work before you installed the speedball?
Title: Re: Terminal 7 at 140v and no right channel
Post by: Paul Birkeland on September 25, 2014, 07:19:35 AM
You very likely have a cold solder joint on the large PC board.

You have one photo looking down on a TIP-50 from the top side of the board, and I can see the legs of the TIP50's going into the through holes on the PC board, but there isn't any solder between them.

This would mean that none of those solder joints have been heated long enough, and I would pull that whole board and reheat every joint. 

The red B+ wires are all connected together on the board, so there's no need to worry about accidentally shorting them together.

-PB
Title: Re: Terminal 7 at 140v and no right channel
Post by: KcMsterpce on September 25, 2014, 01:55:26 PM
Thanks for the information and advice. I will prep my gun, get the lead out and solder on!
Title: Re: Terminal 7 at 140v and no right channel
Post by: Paul Birkeland on September 25, 2014, 02:01:05 PM
I will prep my gun

That could be part of the problem.  If you're using an old Weller gun, consider buying a $4 45W iron at the local electronics store for a little better precision and control.

-PB
Title: Re: Terminal 7 at 140v and no right channel
Post by: KcMsterpce on September 25, 2014, 05:31:37 PM
I was doing bad wordplay. I have a classic soldering iron that an electrician/guitar amp builder let me borrow for the project.
It's just that "gun" works better if you later say "get the lead out" and "soldier/solder on". :/

I'll update once I resolder.