Ender 3 overshot the set temperature and hitting MAX TEMP error

So for the past few months I have been printing in my Ender 3 and everything ran smoothly. But suddenly a few days ago I tried to print and the hot end temperature just keeps on rising past the set temperature of 230. I tried PID tuning, changing the nozzle, hot rod, and the thermistor nothing seems to work.... I even took out the main board and check whether the solder joints are loose, none so far. Any ideas on how to fix the problem?

• Some things I can rule out: your nozzle is not at fault, and it is most likely a firmware thing. Some questions: 1) did you alter/swap the firmware? (You need to flash a bootloader iirc) 2) you print ABS or some other "hot" plastic? 3) can you use a terminal and tell us at what temperature you get the max-temp? – Trish Mar 10 '20 at 7:54
• Nope I have never alter or configure the firmware, for the print material I always use PETG, and for the max-temp it always blows out at 300. Maybe for extra information, I tried to bring the temp to 120 and it goes past that to somewhere around 210 then went back down to 100, then it just starts to fluctuate from 100-170. – Brilliant Purnawan Mar 10 '20 at 8:00
• that sounds like really badly tuned, yes. I strongly suggest to swap the firmware, because at some point the ender-3 had no Thermal Runaway Protection. Maxtemp is a start, but we want proper TRP and PID-tuning, and that needs you to have a proper firmware. I point to 3 questions: Bootloader w/o Arduino, bootloader w//w/o arduino and... – Trish Mar 10 '20 at 8:07
• Hmm I guess ill try that first , thx – Brilliant Purnawan Mar 10 '20 at 8:08
• ...(Where is that last one...) making your own firmware - that last one is a step-by-step guide to get your firmware set up. You don't necessarily need a booloader even, but having one allows to alter the settingss much easier. Also, did you M500 after the PID tuning? – Trish Mar 10 '20 at 8:10