Bed/board issues.....
Hello!
When preheating, or printing from my SD card the bed temps continue to climb even after hitting the setpoint. I can set the bed preheat for PLA (60), but the bed temp will climb until I hit reset, or turn the printer off. No error message, no beep, nothing. I have let it run up to 100 on the bed before hitting reset.
New parts I've installed; 1. heat bed, 2. new bed thermistor,3. and new flexible silicon power wires to the bed. Continuity in all contacts, the thermistor passes the room temp/hairdryer test. I flashed the firmware today, running 3.13.0.6873
The firmware seems to be obeying something, as the machine detects too much heat on the bed and it cuts power to the hot end. So the hot end is cooling, but it continues to heat up the bed. Again, no error message.
But when i put the printer into self-test, it will not power up the heat bed at all. No LED, no heat. Nada. And fail the self-test. But if i use a preheat command, it will heat until it goes nuclear. A friend on FB wondered if perhaps a had crossed the power wires of the hot end and the heat bed. I switched them to see and powered on the printer. When commanded to preheat, the F3 fuse blew on the mainboard. It's very strange. The machine heats on command, it has forgotten how to read it's own bed thermistor. Thanks for reading all. I appreciate it.
RE: Bed/board issues.....
So go to setting temperature and set bed to 60 what does it do
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RE: Bed/board issues.....
Don't heat extruder only bed
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RE: Bed/board issues.....
What does the temperature display on the LCD show when you heat both heaters with a hair dryer?
wbr,
Karl
Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.
RE: Bed/board issues.....
Hello: I go to settings -> bed, and set the temp to 60. The hot end temp begins to climb, but the bed does not heat at all. The hot end gets to about 90, and the machine throws a BED MINTEMP ERROR. I've got something backwards somewhere....
Karl-Herbert: The bed temp starts at ambient, but begins to rise swiftly as i apply the hair dryer.
RE: Bed/board issues.....
Ok... I got it. I had the hot end/heat bed wires swapped on the RAMBo board. I tried preheat again, and the F3 fuse blew instantly. Off to the autoparts shop for replacements, and i hope i don't have a bad RAMBo.
RE: Bed/board issues.....
The logic so far:
Set hot end temp to 60 -> Hot end temp goes to 60
Set heat bed temp to 60 -> The bed LED flashes, and the F3 fuse blows. This has happened twice now, so it's not bad luck with fuses.
Swap power leads between the hot end and the heat bed at the board -> preheat for PLA. Both the hot end and the heat bed begin to heat up- but no fuses blown. If there was a dead short in my bed or wires it should blow a fuse.
Very confusing, and thanks for the help.
RE: Bed/board issues.....
Take a picture of wiring in rambo
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RE: Bed/board issues.....
Please note i've bundled cables/removed cover to get a better view. I've also sent a heat bed command with the heat bed power wires unplugged from the RAMBo. No popped fuse. Is there anything on the heat bed itself that could go wrong? My wire/connections all meter out ok. And thanks again!
RE: Bed/board issues.....
Do you have mk3 or 2 as that looks like mk2 also are you sure red and black wires are the right way round if do the pcb in the heated might be damaged
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RE: Bed/board issues.....
We are in the MK2.5S forum, and the MK2.5S uses the MK2 board so I see no errors on this side.
I instantly thought the hotbed wire was swapped to another terminal on the board but the fuse blowing sounds like a pretty bad sign.
To me, it looks like the board might need repair or replacements. But before that, my recommendation is to thoroughly go through the assembly instructions and completely check / rewire the board as at this point the user error might be more than just one.