Hey if thats resin just heat the unit up substantially and then once its hot enough take a flat head screw driver or something similar and LIGHTLY scrape it off. I heard its bad for the unit to be on without a capsule in it especially on the higher settings, so be careful with it. Seems odd you didn't notice the buildup
Definitely seems like the source for your taste problem.
Although I like your idea to warm the chamber to aid in loosening the scorched gunk..... I can't really buy into telling anyone to scrap it with a screw driver....that polimyde layer is not only I'm sure very thin it is also very likely brittle from all the heat it has been dealing with..... I would in fact think that much or at least some of the discoloration is do to all that heat.....
Yes cleaning is a good thing in here....I have found it doesn't need it as much as the cap and tube I use...
I typically have to scrap the tiny droplets inside my tube every couple of weeks...I would say I'm able to stretch a cap through 2 maybe 3 tube cleanings...by then it's screen has begun to collect gunk even after scrapping and reclaiming the inside of it.....so into an ISO soak {for days} when I'm ready to put another one in the bath I take one out and clean it thoroughly with a Q Tip.... almost all of mine have 2 scorch rings that I haven't been able to get ride of....but the rest is clean
Now the inside chamber I've notice will need to be cleaned every couple of months for me....but the tell is when you begin to notice it is a bit hard to pull on....even with a freshly cleaned cap....take a look inside with a pen light and if you can't see the grid of the screen......you are overdue for a cleaning...
I really liked Vitolo's described process.....trying to vacuum out debris is really the only way to get the flakes you see below the screen area.....which btw is nothing more than a small white disk with a tiny raised metal platform where the screen rests....the raised platform will look to have 3 almost half circle openings...this is where the 2 stage warmed air enters the capsule when we draw.... if you want to try to push or blow out some of the dust you can see down there.....I plug the hole on one side and blow into the other hole and then tap it on a book or something....not to hard though...as we don't want our battery to crush the circuit board and it's components directly under the chamber now do we.... tapping the sides also works with less concern....
I agree with everybody here though..... you are gonna be so happy when she is all cleaned up and once you get a routine down as to the when's to keeping her clean and tip top.....the TASTE will remain