Hi there... we as moderators of the Forums are not actually repair technicians, so our knowledge of component-level repair is not extensive. (If we had that knowledge, we'd probably be fixing gear and not answering threads on the Forums...). What we do is provide some basic troubleshooting suggestions; if the issue points to hardware related failure, our recourse is to direct users to the nearest repair tech for on site diagnosis of the particular unit.

When runtime issues like the one you're experiencing (no output when you activate a Preset), this points to DSP component related failure. In a scenario like this, the only fix is to replace the entire mainboard most likely. It's rare that a tech will do a specific component replacement (time/cost).

I understand your position too, the cost of repair could outweight the cost of a new or used one on eBay. But in regards to servicing your existing pedal, we typically have switches and mainboards as serviceable parts. Customers can always purchase replacement parts through our Authorized Service Centers (ASC), since we don't do direct sales. They can sell you a mainboard and if you or someone who is a tech you know of can do the work, that might be an option. Sorry to hear that your unit is having issues. DL4's are one of my faves.