I'd like to chime in here with some experience from W.A, not as a service technician, but as the occasional meat in the sandwich between a client and a service technician, for work both in and out of warranty. Here in Perth, we have seen the closure/retirement of many reputable service centres within the last five years. As a consequence, the existing pool of techs have been overburdened with work, and unfortunately timeframes have blown out. My experience with the techs I liaise with is they don't like NOT being able to fix things. I mean, at the end of the day, they dont get paid until the unit has been repaired and collected by the client, so it is in their best interest to get the job done as quickly and successfully as is possible! All products require identifying the problem(s), but keep in mind that this could be something as simple as an obvious physical issue, to something more intermittent that requires time to diagnose, to effectively considerable work and time carried out to be sure that the original problem that an item was booked in for doesn't have other issues that the client was unaware of to begin with. I'm pretty sure all service centres charge an inspection fee, but in some cases a technician may need to spend hours to diagnose a problem that could be either cost prohibitive or unable to be fixed, and that inspection fee doesnt always cover the time they will initially spend on the diagnosis.
And I havent even covered the ordering of parts and timeframes associated etc etc.
Again from experience, the equipment I have been involved in that retains some kind of fault after been to a technician, is usually a result of the client pressuring the tech into getting it back in their hands ASAP. I would much rather be without a unit for 8 weeks knowing its been completely repaired to its former glory, than to get it back after a couple of weeks where it hasnt been fully diagnosed (and I have some of my own equipment that has been a victim of this!).
I don't think technicians really care about Google reviews, service is a dying art and I wonder what will happen in 20 years - it seems there is very little new blood being trained up into the industry. Some techs may have over a hundred units in at any one time, and I think while we all want to feel warm and fuzzy and kept in the loop (as would I), i think technicians would much prefer to get on with the job.
I fear we will become a society where when it breaks out of warranty, we throw away and buy again. We just won't have the options we have now.