Hey y'all.
Got a half-broken Truetone 1 Spot CS 12 pro that I intend on fixing. The first six outputs aren't working (2X 18v 100ma and 4X 9v 100ma) and the rest work just fine. The broken ones output around 1V DC with 300mV AC ripple. I find online that when cs 12's fail, this is often the failure mode. People generally just recommend sending it back to Truetone for repair, which makes sense, as messing with an SMPS can be deadly if you don't know what you're doing. This one isn't too dangerous, as I measured any potential voltage hotspots and they seem to drain pretty quickly.
I was wondering if anyone knows where I should look to find the failure mode on these? The back of the board is pretty dense with SMD stuff. I doubt there are schematics (I couldn't find any), but if someone knew where to source them that would be great!
Any help would be greatly appreciated!
Got a half-broken Truetone 1 Spot CS 12 pro that I intend on fixing. The first six outputs aren't working (2X 18v 100ma and 4X 9v 100ma) and the rest work just fine. The broken ones output around 1V DC with 300mV AC ripple. I find online that when cs 12's fail, this is often the failure mode. People generally just recommend sending it back to Truetone for repair, which makes sense, as messing with an SMPS can be deadly if you don't know what you're doing. This one isn't too dangerous, as I measured any potential voltage hotspots and they seem to drain pretty quickly.
I was wondering if anyone knows where I should look to find the failure mode on these? The back of the board is pretty dense with SMD stuff. I doubt there are schematics (I couldn't find any), but if someone knew where to source them that would be great!
Any help would be greatly appreciated!
Maybe this isn't the right category for this kind of unit? I know it is a power supply, but it's nothing to do with amplifiers.
I figured it out - a shorted diode on the back of the board. I also emailed Truetone customer support. They can't give me the schematic, which is expected but unfortunate, but they did give me a page from what seems like an official trouble shooting guide that's for internal use. I almost certainly don't have any sort of permission to post that here, but it's not that complicated. It suggested areas to check for shorts and what diodes model to replace where. The particular diode that was broken on my model was a US2G, like the rest of the diodes with SMD package type, but the troubleshooting guide suggested replacing it with a US1G, whose main difference is its lower forward current. I will follow this guideline, and if it blows up again, it is easy to replace.
If you're finding this post after your own CS 12 stopped working in a similar manner, I absolutely am not recommending you do this yourself. Proceed only if you know the danger points of a modern SMPS! In theory, the voltages present in a unit like this can be enough to kill you, even after it has been powered off and especially if it is powered on.
If you're finding this post after your own CS 12 stopped working in a similar manner, I absolutely am not recommending you do this yourself. Proceed only if you know the danger points of a modern SMPS! In theory, the voltages present in a unit like this can be enough to kill you, even after it has been powered off and especially if it is powered on.