Hello, Should this be in Subwoofer forum? My lovely 2007 PB-13 Ultra started making a repetitive 'thump' through the speaker with no input (just power lead). Listening at the backplate you could also hear a ticking from the amp. After removing the amp (see SVS... image) I've located this ticking to a single component (highlighted on Indigo... image) on the Indigo 640047 rev 3. I assume this is a relay and from reading around probably part of the speaker protection system.
Is it likely that this relay is the cause of the problem or is the ticking an effect of some other problem (protection being repeatedly triggered)? Will I only find out by replacing it?! I am handy with a soldering iron and multimeter but don't know where to start to diagnose an electronics problem at this level. Any help very much appreciated!
Thanks
YouTube vid of the problem; YouTube
Is it likely that this relay is the cause of the problem or is the ticking an effect of some other problem (protection being repeatedly triggered)? Will I only find out by replacing it?! I am handy with a soldering iron and multimeter but don't know where to start to diagnose an electronics problem at this level. Any help very much appreciated!
Thanks
YouTube vid of the problem; YouTube
Attachments
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Having found this post it may be that there is a blown (as in destroyed/missing) component at R48. I've attached images of my board which are similar to that in the post linked above except that my board still has the legs of whatever used to be there!! Looking for problems on the board originally I thought it must have been a build/test component that had been snipped off but now I don't think so.
Is this likely to be a cause or effect of the overall problem?
Can anyone identify what should be at R48 please?
Thanks very much!
Is this likely to be a cause or effect of the overall problem?
Can anyone identify what should be at R48 please?
Thanks very much!
Attachments
The power supply is failing, attempting to start repeatedly but can't. Being a switchmode PSU, the first thing to have tested will be the electrolytic caps. which this type relies on to convert mains voltages to lower, stable DC voltages. However, bear in mind that once removed from the speaker cabinet, SMPSs like this have exposed lethal voltages on the PCB, top and bottom, of up to twice the mains voltage. Don't handle or mess with this even disconnected from the power socket if you value your nervous system, if not your very existence.
BTW, the special low-ESR, high grade caps used in these can hold considerable charge for long periods. They should be safely discharged before touching the amp with bare hands. Sure, some people do get away with poking around inside these supplies but others, even the odd service tech, do get fried
Unless you do know what you're doing and didn't need to ask, have it serviced safely by a tech. who knows what type and spec. replacement parts will be needed. It may not be necessary to have an audio tech. service the supply as this type of power supply is now standard in most home entertainment appliances.
BTW, the special low-ESR, high grade caps used in these can hold considerable charge for long periods. They should be safely discharged before touching the amp with bare hands. Sure, some people do get away with poking around inside these supplies but others, even the odd service tech, do get fried
Unless you do know what you're doing and didn't need to ask, have it serviced safely by a tech. who knows what type and spec. replacement parts will be needed. It may not be necessary to have an audio tech. service the supply as this type of power supply is now standard in most home entertainment appliances.
Yeah, thanks for that, I do appreciate and understand your concerns. However I'm not sure about, "this type of power supply is now standard in most home entertainment appliances" because everything I've read about these BASH amps is that professional "fix anything" shops won't take them on without schematics which aren't available.
BTW I now have good advice that R48 mentioned in my post above is in fact empty on working boards so the problem is nothing to do with that.
BTW I now have good advice that R48 mentioned in my post above is in fact empty on working boards so the problem is nothing to do with that.
Correct. You can see the resistor was removed intentionally by the snipped lead. This is not uncommon as part of either a setup/test procedure in manufacture or probably later in this example, when the "sub" builder installed the plate amp. Price is king today, so cheap procedures are used everywhere, even on prestigious brands.
You could well be right about repairers being unwilling to research or lift a finger to get the manual (if one exists) themselves. However, the obvious problem is the power supply has failed and before any other problem can be solved, that section of the plate amp assembly should and can most likely be repaired without great drama. FWIW, the BASH principle is a variation on class D amplifiers where a cleverly implemented and very efficient class AB stage follows the class D amplifier to clean up more of its high frequency noise and distortion garbage. The amplifier section and its problems if any, will still be distinct from the power supply and its problems though.
This seems to be a familiar fault with Indigo's plate amp. but it seems to be difficult to contact them for service requirements (if indeed they are still in business). SVS sub -Power board Indigo 640047 help
BTW, there's unlikely to be any relay in there that's large enough to handle the power of these monsters. At least I don't see any in the power supply section identified by your markings. As said, this type of power supply is an SMPS or switchmode power supply which is indeed everywhere in modern consumer electronics. The power supply and amplifier with its control circuits and connections are all separate sections of the complete plate amplifier.
You could well be right about repairers being unwilling to research or lift a finger to get the manual (if one exists) themselves. However, the obvious problem is the power supply has failed and before any other problem can be solved, that section of the plate amp assembly should and can most likely be repaired without great drama. FWIW, the BASH principle is a variation on class D amplifiers where a cleverly implemented and very efficient class AB stage follows the class D amplifier to clean up more of its high frequency noise and distortion garbage. The amplifier section and its problems if any, will still be distinct from the power supply and its problems though.
This seems to be a familiar fault with Indigo's plate amp. but it seems to be difficult to contact them for service requirements (if indeed they are still in business). SVS sub -Power board Indigo 640047 help
BTW, there's unlikely to be any relay in there that's large enough to handle the power of these monsters. At least I don't see any in the power supply section identified by your markings. As said, this type of power supply is an SMPS or switchmode power supply which is indeed everywhere in modern consumer electronics. The power supply and amplifier with its control circuits and connections are all separate sections of the complete plate amplifier.
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