I am rebuilding my homemade i3 clone after converting to klipper. I am using a generic 24v PCB bed from aliexpress. Whenever i try to set the bed to heat I can see current flowing through the mcu connectors to the bed with a multimeter, but it doesn not heat. After about 5-10 seconds it causes an error and says that the connection with the mcu had been lost.
Things I’ve tried so far are:
1 - connecting a different bed (silicon mat not PCB) to the mcu. This succeeds in heating the silicon bed, so i dont think it’s the board that has a problem.
2- connecting the bed to a different printer. This successfully heats the bed. So i dont think it’s the bed itself either.
I am pretty illiterate on the software side of things so I’m not sure how to interpret the klippy log, but every time I attempt to heat it I see “b’Got EOF when reading from device’” in the log.
Can anyone think of a reason why this error keeps appearing or any way I can get past this issue?
I was measuring the current by putting the multimeter probes to the terminals. I just did it again and it seems that somehow it is trying to put out more than 30 volts and gets to about 33 volts before it shuts down. I tried the same thing with the hot end terminals and it holds steady at 24 volts. The power going to the board is measured at 24.1 volts as well. I tried adding “max_power: 0.6” to the config, and that did reduce the voltage and it holds at about 13, but it still shuts down after about 5-10 seconds.
This is a little confusing. You measure a current, which would be correct, but never mention ampere?
How did you connect the multimeter to your bed? You may just post a picture.
So for some reason it works now. I have no idea what changed, as everything is identical to the way it was this morning, but I guess after plugging and unplugging everything all day I shook something the right way. The only thing I can think of that is different is that I maybe flipped the thermistor wires around but I was under the assumption that thermistors did not have a polarity.