Sudden loss of first layer adhesion after approximately 120 hours
I have a MK3S+ that I bought pre-assembled and used successfully for about 120 hours (mostly PLA, some PETG) when suddenly I could not get first layer adhesion at all after completing a print. I tried all the obvious things first. I cleaned the steel spring plate with IPA, carefully washed it with soap and water, and even used acetone to no success. I tried drying the filament. I changed filaments to new filament and different filaments (ABS), no good. I put the brand-new satin coated plate on as well for the ABS, still no good. I gave everything a good lubrication and cleaning just in case. I recalibrated using the wizard and have been banging my head against the live Z adjustment, with no luck so far in finding the sweet spot. I haven't taken the nozzle off and replaced it yet, but that was my next thought.
Is there something simple and obvious I'm missing? I realize that pictures of the live Z would help, but sometimes I can't get that or the square bed leveling print to stick well either.
Show us what you do manage to get, that can be informative too.
Cheerio,
RE: Sudden loss of first layer adhesion after approximately 120 hours
Sorry I'm so late getting these posted. These are 0.750 and 1.00 mm z-adjust. I couldn't even get the 0.500 or lower to stick on the plate because of the back adhesion failure. The 0.750 should be the first photo. 
RE:
Other than that your nozzle is high up in the clouds, judging from the single lines of filament instead of nicely squished lines - are you using NON-REGREASING dishwasher liquid? There´s this stuff with aloe vera etc which will happily leave grease on your build plate. No acetone please. Sponge, dishwasher liquid and SCRUB IT!
Cheers
Chris
I try to give answers to the best of my ability, but I am not a 3D printing pro by any means, and anything you do you do at your own risk. BTW: I have no food for…
RE: Sudden loss of first layer adhesion after approximately 120 hours
Wash the plate with Dawn dish soap and hot water. All will be fixed. The first signs of it needing a good wash is that parts of the skirt stop sticking. I don't have much luck cleaning with alcohol, except a a very temporary stopgap. Washing works fantastic every time.
RE: Sudden loss of first layer adhesion after approximately 120 hours
I have tried washing with something along the lines of Ajax liquid soap before I kept trying to find a solution, but I can try it again with something else. Regarding the z-offset, my mistake as I thought the z-offset only went negative and went absolute value on my numbers. They are -0.750 and -1.00 mm respectively.
Your first layer Z needs to go a lot lower, you are getting hardly any squish and just draping round strands on the bed. You can probably jump straight to -1.200 and then go down in steps of -0.200 until you see a change and must resort to smaller steps.
Although the handbook says not to go beyond 1mm adjustment it is generally safe to go as far as 2mm. If it approaches this limit come back here and ask how to reset your sensor which may have been knocked off position.
Cheerio,
RE:
Thanks everyone. I've got it looking good in PLA on the smooth at about -1.75 and in ABS on the satin at about -1.85, though I found I had to adjust the bed leveling up a bit for the front right. Trying to actually print a model now, so won't know for sure, but I think it's sticking well.