Also have an MVAE. Great stove except for thermostat but I have ranted enough about that elsewhere. As for thorough cleaning:
1) Re-read Kappel15 post above. He, Bogieb and Swilliamson are probably three most knowledgeable members of forum (all techs, I believe, and I know Kap is). LakeGirl also excellent source of common sense approach to almost any problem.
2) Unplug stove from electric outlet. Do normal cleaning as per manual, including removal of baffle (large metal plate) in back of firebox and vacuuming of small openings at bottom, visible when baffle is off. If this does not make sense, you have not read the manual, so start again there.
3) Leaving plate off as you proceed with process, remove sheet metal on sides of stove to access fans. Looking at stove from front, combustion motor is on right. Remove six nuts holding it in place, BUT AS KAP NOTES, MAKE SURE YOU FIRST HAVE THE REUSABLE ORANGE GASKET FOR THAT PART. You will need it, as gaskets are essential and do tear and stick easily. The orange one has lasted me four years and counting, as I recall. Clean the motor area with vacuum and brush, including fins. Then take small brush (I use flexible one designed for internal dryer vent cleaning) to clean the pipe running up from motor area as far as you can get with that (a foot or so). You will need to be vacuuming the whole time with a HEPA vac filter in place, or ash will go everywhere. Then take brush in other direction, into stove, toward small openings at bottom, under baffle. Vacuum like crazy as you do this.
4) For this step, you need pellet stove brush and flexible rods. Rutland makes excellent versions of both that will last many years. Check local stores or Amazon. Now you need to clean your vents (exhaust pipe) for which you will need a 3" pellet stove cleaning brush and, if your pipe expands larger than this anywhere after back of stove (pic makes me think yours does), a 4" brush. I do this by removing a section of pipe just past the back of the stove and another outside, as I have an "out and up" configuration. It looks like you have a pipe that turns up just after exiting back of stove, so I would see if you have a clean out tee back there (if not, I would install one). Basically, you need to run appropriate size brush through entire section of pipe, which will produce much ash and soot. Again, keep vacuum running at all times. You will also need to brush back toward stove motor, probably with 3" brush. The rule of thumb is that if you have not THOROUGHLY brushed every inch of pipe, you have NOT properly cleaned your stove.
5) Once combustion path clean, reassemble everything. This process takes me about 75 -90 minutes. I'm sure experienced techs might do it a bit faster, but I seriously doubt the previous person did all this, as 30 minutes sounds much too fast. I also find that silicon wrap (many call it "tape", but there is no adhesive) wrapped around sections that I remove to do all this is fantastic. Keeps pipe from allowing smoke to escape while allowing for removal.
6) Once combustion path clean and reassembled, go to other side of stove and remove convection (room air) blower. There is latch that holds it in place, and then it just drops down. Remove this motor (unplug it) and clean the fins of the blower. All of them, equally... I personally hate this step as I never get it as squeaky clean as I wish, but it does help with circulation if especially dirty. Reinstall when done.
7) Plug in stove and test. It will go through a self clean cycle and then, assuming you have thermostat calling for heat, fire up. If all well, reassemble sheet metal sides and you are done.
I do this twice per year but run about 3 tons through my stove each heating season (and have another stove, a Santa Fe, that gets similar cleaning).
When hopper runs down, I also vacuum it out to get rid of fines. I do this maybe once per month, and also do a cleaning that involves just removing the back bafffle and brushing /cleaning that area and the openings at bottom, once per month. Takes maybe 30 min tops. Clean glass about once/ week, which is frequency of vacuuming out firebox and ash pan.
Others please chime in on steps I have forgotten.
The manual is usually the best information source ... some are lacking best info though. They sometimes fall back on the call the dealer (mine does and the translation from Italian leaves room for improvement) Member kappel15 is a very reliable source for repairs having serviced them for many years. Always unplug when working in the cabinet and make sure it has surge protection. Hopefully you have smoke and CO detectors installed. Fire extinguisher away from the stove is an extra insurance policy.
. I do believe you momentarily confused me with another whose screen name starts with a B 
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