About half a year ago I built a TRemPre Tube pre-amplifier kit from dantimax.dk. It's a nice little pre-amplifier utilizing a 7861 tube, an ALPS motorpot, remote control functions, etc.
As of a couple of months ago the preamp isn't working as it should be. Powering up/off and muting works, but I can't get any signals from the input. The tube heats up nicely, I'm measuring the right voltages everywhere. The relays don't click on/off. After removing the HC148 controllerchip for the fronstide inputswitches and trying to only use the remote control doesn't work.
I've got to remind you that this was one of my first projects. My soldering skills weren't really that great and I had to remove one of the resistornetworks (the one closest to the HC148 chip) because it was inserted the wrong way around. While doing this, I destroyed one of the copper connections on the PCB and had to fix this with a wire. This however seems to be working fine, because a few months ago the amp still worked nicely.
It's only been like this seens a couple of months. I hadn't had the time to continue searching for what exactly caused this problem and now I'm quite unsure where to go. Mikkel from dantimax.dk tries to help, but I'm not very willing to send it back to him.
Has anyone got any ideas?
The schematics
The board from above
As of a couple of months ago the preamp isn't working as it should be. Powering up/off and muting works, but I can't get any signals from the input. The tube heats up nicely, I'm measuring the right voltages everywhere. The relays don't click on/off. After removing the HC148 controllerchip for the fronstide inputswitches and trying to only use the remote control doesn't work.
I've got to remind you that this was one of my first projects. My soldering skills weren't really that great and I had to remove one of the resistornetworks (the one closest to the HC148 chip) because it was inserted the wrong way around. While doing this, I destroyed one of the copper connections on the PCB and had to fix this with a wire. This however seems to be working fine, because a few months ago the amp still worked nicely.
It's only been like this seens a couple of months. I hadn't had the time to continue searching for what exactly caused this problem and now I'm quite unsure where to go. Mikkel from dantimax.dk tries to help, but I'm not very willing to send it back to him.
Has anyone got any ideas?
The schematics
The board from above