Maybe, though it really depends on the equipment, the fault and your skills and equipment.
You must have realistic expectations though. If you’ve ever tried to help Grandma fix her computer over the phone, you’ll know exactly what I am talking about! Does the person have the right tools, do they have a multimeter and know how to use it, desoldering equipment, parts on hand, etc, etc, etc.
This sort of remote assistance can be one of the most challenging tasks humans are faced with, so we need to pick our battles. I also don’t want to guide you into a situation where, because you lack the requisite situational awareness to work on electronic equipment, you hurt yourself.
If you are a novice and expect me to guide you through fixing your blown amplifier, this is simply not a realistic expectation. In most cases, it’s not sensible for owners to attempt to repair their equipment, but with the right guidance, many simple problems can be identified and sometimes even fixed.
We offer more great information for free here @ Liquid Audio than probably any other independent, specialist source, so check out other FAQs, reviews and so on for much more.
For those needing more specific assistance and who cannot bring equipment to me, I offer a personalised advisory service consisting of advice blocks and consults. These allow us to have a proper discussion I can allocate time to and where both parties benefit. A win-win!