TB6600 Alarm light on but still functioning

I am having issues with a Novusun v2 and TB6600 drivers on a 4 axis machine. I have wired everything according to the minimal instructions I have found and after fixing some software issues, everything is communicating and the steppers are appearing to work just fine. The problem I am having, is that of the two LEDs ( PWR and ALRM) only the ALRM light is showing and has only ever shown. The drivers are also getting quite warm, so I'm not sure whether to just ignore the lights but I'm worried about burning something out etc. I'm a newbie so any help with this would be greatly appreciated!

OK I'm still a bit of a "newbie" myself at driving steppers but I have a long background in other types of controls. It sounds as if you purchased the drivers separately from the rest of the system as most of us do, there seem to be few "hard and fast" standards for these things except that the features provided by the TB6600 chip itself will generally be available. Now the alert signal that powers the "alarm" light responds to either overcurrent or overtemp, I can't say anything about why the power light isn't on because that's not a chip feature. It also sounds likely that the drivers you have don't have an idle timeout, when present this is generally provided by a small, simple hardware timer chip that times out after a short interval of there being no new step pulses presented. If there's no idle timeout then the coils will be presented with the same current continuously, thing is when driving many of these larger steppers (I'm thinking 4 amps or more) the efficiency of the output bridge may be as low as about 50% so there's a lot of heat to be dissipated there. I'm not going to make any "system decisions" for you as to whether you can tolerate a lower current going through the coils when they're not moving anything, but I CAN tell you that the heat sinks they provide on most of these drivers are entirely inadequate as designed to dissipate the heat under these conditions if an idle mode does NOT exist. (You could try putting about a 50 mm square fan [that's about the right size for a single axis driver] right over the fins but I wouldn't get my hopes up too high.) Now there's a lot of us with drivers that DO have an idle mode who think the timeout on this is altogether too short but it sure beats having the chip too hot all the time. Like I say based on what you're telling me the alarm is for overtemp but sooner or later that may cause an output device on the chip to fail, and that may or may not be "obvious" depending on just about everything. As I say if you feel you can tolerate it you might consider trying out a driver with an idle mode, and you might just consider sticking a fan on THAT if you're into belt and suspenders like I am. I've probably said at least as much as I really know (we both want to hope I didn't go TOO far past that!). I may not know all you need to but at least I've put down some things to think about, good luck!

It wouldn’t be the first time that Chinese drives have been labeled wrong. Some of the older TB6600 drives I have, the silkscreened microstepping dip switch settings are wrong.

Possibly your alarm/power labels are reversed.

My tb6600 drives run rather warm especially if you have them set near max current