Re: brand new factory build Mk2 has Thermal Runaway Error
hi guys
ok well i have had more time to play with the mk2
if i use the SD card with for example the whistle model...the hot end goes to 210 and then drops fast to 199 or so once the fan starts,...and it stays there for most of the print..but rises as the hot end gets higher from the bed...this is with the fan speed at 100% on the supplied sd card models
if i adjust the temp to say 215 during the print then the hotend does not come up any higher temperature than 199...seems like the fan is cooling it down
does that seem normal?
is the sock my only solution?
Re: brand new factory build Mk2 has Thermal Runaway Error
John
A couple of things:
Unplug the heater connector at the RAMBo end and replug. Do this a couple of times to ensure the connector is clean and is seating properly.
If you have a multimeter, when you have the connector unplugged, measure the resistance of the heater and cable by putting the probes on the screw terminals of hte connector. Let us know the resistance value as measured. (Note that you should also measure the resistance of the multimeter leads by touching the probes together, then subtract that reading from the heater resistance reading.)
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: brand new factory build Mk2 has Thermal Runaway Error
with the heater connector unplugged from the pcb the heater resistance is exactly 6 ohms
the connector was dam tight to get off...ill reconnect it again
Re: brand new factory build Mk2 has Thermal Runaway Error
John
That works out to about 23 Watts at 11.75V, which is thereabouts what a 12V rail will provide.
23W is very much on the low end of what is required and is most likely the cause of your issues.
So there are a few things you can do:
1. Contact support - use "live chat" on the shop pages and give them a link to this thread.
2. Increase the PSU voltage. Remove the PSU and plastic cover; there is an adjustment pot near to the screw terminals. Increase voltage by about 0.5V.
3. Insulate the heater block - either treat your hot end to some socks or try wrapping it with Kapton tape.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: brand new factory build Mk2 has Thermal Runaway Error
THANKS PJR
i contacted support and they recon you are correct and i should adjust the voltage
they will send me instructions
lets all hold hands and chant...i can feel a explosion coming on heheh 😀 😀 😀 😀
Re: brand new factory build Mk2 has Thermal Runaway Error
UPDATE
prusa support have asked me to send back the printer for inspection and will deliver a new replacement at same time
top job on the service !!!
and many thanks to the guys on the forum for the time and effort helping me solve this small issue
cheers guys ill let you know how i get one with the replacement