If you look at the driver datasheet, they are supposed to be cooled via thermal pad on the bottom. It is advised against to cool them with heatsink on top of the package, as it provides a lot of stress on the chip package and cause failed drivers.
RAMBo mini has thermal vias and 4 layer pcb to cool it down the proper way with the whole PCB.
The current for rambo mini is set in pins.h, it is not set with digipot but thru PWM.
If the connector for your heatbed starts to melt, it is very likely caused by making the terminal on the connector not tight enough or not pluging it completely in. Once it starts it is best to solder it on the back of the board as the connector oxidises inside and tightening won't help anymore.
To your original problem, the driver is 99% fine, it is the motor connector or cable. Sometimes it gets broken during printer assembly when one of the four leads gets broken. Did you try switching the motors to see if the issue transfers?
We ship out 300+ printers a month and I haven't seen a blown driver on RAMBo. It is sad for me to see it replaced with fake RAMPS board :-(
I can't find any posts from you on official forum or even email requesting help. We sell replacements and even hold 2 year warranty so don't hesitate to contact us thru our official channels, we even have 24/7 live chat on our websites. It was a coincidence I found this topic ;-)
Jo Prusa
RAMBo mini has thermal vias and 4 layer pcb to cool it down the proper way with the whole PCB.
The current for rambo mini is set in pins.h, it is not set with digipot but thru PWM.
If the connector for your heatbed starts to melt, it is very likely caused by making the terminal on the connector not tight enough or not pluging it completely in. Once it starts it is best to solder it on the back of the board as the connector oxidises inside and tightening won't help anymore.
To your original problem, the driver is 99% fine, it is the motor connector or cable. Sometimes it gets broken during printer assembly when one of the four leads gets broken. Did you try switching the motors to see if the issue transfers?
We ship out 300+ printers a month and I haven't seen a blown driver on RAMBo. It is sad for me to see it replaced with fake RAMPS board :-(
I can't find any posts from you on official forum or even email requesting help. We sell replacements and even hold 2 year warranty so don't hesitate to contact us thru our official channels, we even have 24/7 live chat on our websites. It was a coincidence I found this topic ;-)
Jo Prusa