VintageKustom.com: Repairing Kustom Amps » Quad 100 DFXWT "special edition"

Quad 100 DFXWT "special edition" - repairs [message #25371]

Sun, 07 August 2016 10:36

ghramsey
Messages: 3
Registered: July 2016
Location: Houston, TX - USA

Junior Member

My buddy got this amp from his ex-girlfriend it is a Kustom Quad 100 DFXWT "Special Edition".

The amp has a short somewhere that is making the sound cut out.

Banging on it near the effects circuit board would make the sound come back on or any sound transient input such as
bashing strings on a guitar or tapping a mic makes the sound come back on briefly only to cut off again.

I pulled the main circuit board and found the effects switch was extremely loose and four of the eight solder joints had
pads that seemed to be lifting from the board. This is a BCD switch to select which effect is put into the audio path
I think.

I tried to secure it and tried to re-flow the joints using a low-watt pencil iron, but the pads were just totally
broken from the board as I had originally suspected. I think there are only 4 connected traces and the other four
are to secure the switch to the board. These are the ones that are completely lifted. I suspect a prior repair attempt
based on how badly the pads were lifted. The amp was reportedly dropped while moving from AZ to TX.

Looking at the schematic for this amp it doesn't even look like that switch is even in circuit when the effects are turned off.
The other controls seemed to be OK and I re-flowed solder on one other control where the solder joints were moving when I wiggled the switch.

I reassembled the amp and the issue remains. It still just stops unless it receives a large transient signal.

I did not see any other cracked traces, but I supposed there might be plenty I missed.
I was appalled at how flexible the circuit board is.

Is there any way to fix this amp or is it just a pile of junk now?
What else should I try to look for that might be causing the sound to stop?

Can I buy a replacement circuit board somewhere?

I realize this is a forum for vintage amps. Is there one for more modern Kustom amps?

Any help will be appreciated.

Henry

Report message to a moderator