DD1 powers off seemingly randomly - SOLVED
Vegard Kristoffer Bakken
Member
I just wanted to share my experience with this issue I have had with my DD1 base. It may be relevant to other wheel bases as well, and I spent quite some time figuring out what what going on.
The symptoms were that the DD1 would suddenly just power off, seemingly randomly, while driving. It also happened on occasion when not driving. The power supply would seem ok with the green light all the time, and the DD1 could be powered back on immidiately without issues.
The wheel base showed no other symptoms of malfunction at all, and I couldn't find any specific way to consistently trigger the issue.
By chance, I discovered that it sometimes could be triggered by jiggling the SQ-shifter's stick while in sequential mode, which seemed very strange. And even this would not trigger the issue consistently.
Long story made short: After probing with a multimeter for hours and days, I discovered that my problem was a defective bass shaker which in certain situations leaked voltage into the rig chassis. Being bolted to the rig, this voltage would also reach the chassis of the SQ-shifter. And, obviously, the SQ-shifter could in given situations feed this voltage into its signal cable and to the DD1, triggering an immidiate shut down. Which obviously is a good, built-in safety measure to avoid damaging the DD1 if it's being fed with voltage into the signal ports.
I read many other posts with similar symptoms, but where the exact source of the problem wasn't properly identified.
One working solution found by others was to connect everything, including the rig chassis, to proper ground. That might have solved my problem, as the small voltage from the defective bass shaker would probably then have dissipated into ground, instead of finding its way through the shifter signal cable and into the wheel base. But that's not the proper fix. It could also be quite dangerous, having the rig itself grounded.
Another quick and dirty fix would be isolating the defective bass shaker so that it no longer was grounded to the rig, or isolating the SQ shifter. I haven't investigated the shfiter itself, so I don't know if it's normal that it on occasion will touch ground with its signal cable. Perhaps a design flaw, or it could be a worn or slightly defective shifter. Though under normal operating conditions, it probably doesn't really matter.
But nothing should leak voltage into the chassis of the rig at any time, not even the small voltage from a speaker, or from a shifter signal cable.
So the proper fix for me was obviously to replace the defective bass shaker. Case closed.
Learning points:
- The SQ shifter can in certain situations ground one or more of the leads in its signal cable to the chassis, feeding this to the signal port of the wheel base, possibly triggering an immidiate safety shutdown.
- The rig chassis should be completely isolated from ground and never carry any voltage or current.
- Troubleshooting intermittent problems like these is a pain, and usually involves a combination of problems with more than one unit, where none of them alone can trigger the issue: The defective bass shaker alone would never have triggered it, without the shifter feeding the leaked voltage into the wheel base signal port. And the shifter feeding chassis ground to the wheel base is not a problem as long as the chassis doesn't have any voltage.
Comments
Glad you found the problem. However to claim that grounding the rig is dangerous is absurd. Ground is ground - deliberately adding an extra ground wire to a rig only lowers the impedance of it's existing ground - which reduces any shock hazard - not causes it! I think you are trying to say that it is a bad idea for the ground to be used as a deliberate return path but that is not the case here - grounding merely provides a safety drain for any unintended current that may be present on the rig.
You're probably right, it was just my initial thought about connecting the rig itself directly to anything at all.
And when thinking a bit further, in my case, doing this would probably have tripped the ground fault breaker.