Hi
I have a little active sub that one day decided to quit. The specifics I'm unsure of as I weren't there. But from what I was told it either happened when the sub was being turned on or when the line sub in was connected. There was a really loud pop, and it didn't work after that. If playing it now there is a very faint sign of it working, but I think it's being powered by the signal power itself, meaning the amplifier circuit doesn't amplify... The boards has a relatively simple layout, no surface mount components. I looked carefully over everything, but nothing seems to have failed, the fuses are also intact. I haven't managed to find schematics for it either. Does anyone have any idea of what could be wrong?
Thanks,
MrGecco
I have a little active sub that one day decided to quit. The specifics I'm unsure of as I weren't there. But from what I was told it either happened when the sub was being turned on or when the line sub in was connected. There was a really loud pop, and it didn't work after that. If playing it now there is a very faint sign of it working, but I think it's being powered by the signal power itself, meaning the amplifier circuit doesn't amplify... The boards has a relatively simple layout, no surface mount components. I looked carefully over everything, but nothing seems to have failed, the fuses are also intact. I haven't managed to find schematics for it either. Does anyone have any idea of what could be wrong?
Thanks,
MrGecco
Post a photograph of the PCB and use the attachment function to post it. Readers may be able to recognise the circuit.MrGecco said:
Ok Since it's pretty much impossible to remove the PC's from the bracket, these were the best photos I managed to snap.
The brown stuff that looks like burn marks is some kind of grease.
None of the capacitors are puffed or leaking. I've tested the full bridge rectifier. The voice coil is measuring correct resistance. There are no burn marks on any of the components (as far as I can see). All the traces are intact.
Could it be the transistors?
Any help is greatly appreciated
Thanks,
MrGecco
The brown stuff that looks like burn marks is some kind of grease.
None of the capacitors are puffed or leaking. I've tested the full bridge rectifier. The voice coil is measuring correct resistance. There are no burn marks on any of the components (as far as I can see). All the traces are intact.
Could it be the transistors?
Any help is greatly appreciated
Thanks,
MrGecco
Attachments
You could identify the model so we can locate a schematic for it - that may really help. I see the model 5500 marked on the PCB but there are a few brands like Logitech and MTK who use that too. Which brand is it, as there may be some useful info. in the service manual, if one exists?
Well, that's sort of the problem. It's store brand (argon audio), and probably way over 10 years old. But the woofer has a label saying "8YD-SUB8-4", while the plate amp just says "SUB8". On their website there are newer generations of it, but not the same. That being said, if anyone recognises an older 8 inch sub, that is 29,5 cm (11,6") on all sides, with a down firing port, 80 watts, it may lead to the actual manufacturer.