Greetings,
I recently took possession of an LXII and upon arrival the corner of the shipping box was crushed. The person shipping it doubled boxed it but the back corner of the amp where the input jacks are was pushed and it was enough pressure to shatter the nylon retaining nut on Channel B input. Somehow the jack sleeve survived and was not cracked.
I borrowed the nut off the remote switch jack that I’m not using to temporarily secure the Channel B input, patched everything into my stereo rig and powered it up with both channels in standby and volume at 0.
Everything looked good. Took it out of standby and got normal signal out of channel A but channel B was very faint or about 10% of A. I really had to bring the gain up almost full to get it audible.
I tested a few different configurations just to eliminate outside issues like swapping channels, gently wiggling the input jack to see if there was intermittent signal such as a loose solder joint, different patch cables, direct in each channel, etc.
Then tried bridged mono and did not get any signal. Went back to stereo input confit and no signal at all, even channel A was down which was originally working. At that point I shut it down. Checked fuses and those were all good. Very difficult to self diagnose other than I may have provoked some type of loose or broken input connection by using the inputs that may have been damaged.
I pulled the cover for a quick visual inspection. Tubes look great all seated properly. Input jacks had a little play to them but appear connected to the board but I don’t know what exactly I should be looking for or where to put a meter to test connectivity. The input section is modular and a simple plug and play if that is all that needs to be replaced, brilliant design.
I know this is lengthy but wanted to provide as much detail as possible . I love this amp and it’s built like a tank. I’m sure it is quite repairable but would welcome support.
Best regards!