heatbed wouldnt het higher than 65deg

My old board Sunbeam shat itself, i changed to ramps 1.4 After assembly wiring I got error Error:Heating failed, system stopped! Heater_ID: bed
no matter what settings i put into firmware after it rise temperature of bed to about 65 celsius deg.
How do i turno off THERMAL_PROTECTION_BED?
And maybe you had problem like this?
I got normal aluminium bed with glass, and PSU 12V. I dont know what do.

Edited 2 time(s). Last edit at 07/03/2018 01:21AM by Jackjack.

Not answering that....

You need to check its not real, ie that your thermistor is still firmly attached to the bed

If it is then you need to update your bed PID

for bed pid tuning see [reprap.org]

If that fails edit configuration_adv.h

In particular

#define WATCH_BED_TEMP_PERIOD 60 // Seconds
#define WATCH_BED_TEMP_INCREASE 2 // Degrees Celsius

from the notes just above this

 * If you get false positives for "Heating failed", increase WATCH_TEMP_PERIOD
   * and/or decrease WATCH_TEMP_INCREASE. WATCH_TEMP_INCREASE should not be set
   * below 2.

Thank u for caring but im sure like nothing else there is thermistor for sure connected. I wouldnt be so sure about hotend one but it still there.

What else can be tweaked?

Edited 1 time(s). Last edit at 07/03/2018 01:16AM by Jackjack.

another option is your previous board was 24v and your now trying to heat a 24v bed with 12v... which wont work.

you never said anything about changing power supply.... but you didn't give many details at all

Edited 1 time(s). Last edit at 07/03/2018 03:04AM by Dust.

No last board was working with same printer and 12V psu. But didnt have any kind protection like polimer fuse...
Now i tuched those yellow fuses and burned my finger.
Turns out they were blocking current very well shortly after bed heating start.
I throw them away. I know how stupid it is but it not working with them, also PSU has its own protection. And i got PID and this thermal protection in marlin code.
It works for now.

Quote
Jackjack
But didnt have any kind protection like polimer fuse... Now i touched those yellow fuses and burned my finger.

I know how stupid it is but it not working with them, also PSU has its own protection.

Modern Power Supplies have two forms of protection a thermal fuse to shut down in case of overheating.
Modern Power supplies also include a slow blow fuse/fuse to protect in the case of over current operation.

Just to be on the Safe side, "I have included a Smoke detector inside the environmental chamber for my own 3D Printer just in case. "

I would advise you to add a smoke detector and only 3D Print when in hearing range, until you feel that it can be safely operated.

(" Operate my 3D Printer only when I am close, and have Octoprint w/cameras to monitor from all networked Devices. ")
(" My supplies thermal Fuse was bad from the start, Replaced with a solid Wire, Felt like it still had a slo-blow fuse for protection. ")
(" This is the reason never leave the 3D Printer unattended. However after over a year of operation I walk further away now. ")
(" Although feel that should replace the thermal fuse protection on the 3D Printer Power Supply, if not for me for the Families safety ")
(" Better yet, I purchased a 24V supply to replace the 12V and never installed it. Should Install 24V Supply and make the necessary changes/adjustments. ")

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Computer Programmer / Electronics Technician

I know about protection...
I will have to do something. Now its working basicaly. But i had to turn of bed thermal protection in code. It just constantly interrupted bed heating no mater what.
Last code i had on old sunbeam propably didnt had it either. Or it worked much better.

Quote
Jackjack
I know about protection...
I will have to do something. Now its working basicaly. But i had to turn of bed thermal protection in code. It just constantly interrupted bed heating no mater what.
Last code i had on old sunbeam propably didnt had it either. Or it worked much better.

I tried to get the PID to work on My hotbed but it was always giving me a thermal protection error.

I finally set the bed to Bang bang hot-bed heating and have never had another problem with it.

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Computer Programmer / Electronics Technician