| ALW |
I have a Rockford Fosgate 2600 amplifier I'm looking at for a friend.
It's taken out a few devices, inlcuding the switching transistors and drivers in the PSU and the o/p devices in one channel.
I've got the PSU running, and replaced the o/p devices, but there is some protection circuitry that monitors temp + some kind of power to shut the amp down, which is what seems to be being activated, I suspect by an amplifer fault.
Since it's almost all SMD, I don't fancy drawing the whole schematic, it's a discrete design with 25 or so active devices / channel.
Does anyone have a schematic?
Thanks,
Andy. |
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| asauer |
| Have you tried emailing Rockford Fosgate and asking for the schematics?:cool: I don't know if they'll release them or not. |
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| Immo_G |
| See if the temperature protection is a comparator going to a shutdown pin on the SMPS chip. |
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| EnvisionAudio |
| The 2600 is a fun one. I get about 80% of them working before it costs more to fix than replace. There are some 4401 transistors on the voltage amp stage that short and send full current to the outputs, causing a shutdown mode. They just get too hot. I replace them with MPSA06 devices and that's that. Email Rockford for the schematic - I'm sure they'll give it to you. |
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| ALW |
I'll try emailing Rockford Fosgate to see if they will provide a schematic.
It's become personal now, I don't want to be beat :)
Cheers,
Andy. |
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| ALW |
Well, Rockford Fosgate know the meaning of customer service!
Emailed them today and received a schematic by return (actually placed into a 'My Stuff' folder on their website.
I now feel suitably armed to do battle, although there's not many lunch breaks between now and Xmas to do it :)
Cheers,
Andy.
P.S. the boards have some dual transistor diff pairs littered around and they are the only devices that don't have a part number declared - any idea what they are?
They're NPN SMD devices marked 'W3' but my SMD codebook didn't have them.
I'll ask RF if any are faulty, but if anyone knows I'd be interested. |
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| EnvisionAudio |
Don't worry about the dualies - they don't go bad. Just measure the B-E junction on the voltage drivers (noted by their connection to the tertiary winding - maybe 40V?) and also those in the bootstrap area. I can't recall for sure, but I kept a drawer full of MPSA06 and A56 SMDs around for just such an occasion. I've never seen the schematic for the 2600....
The amps are very forgiving of using the wrong parts, of course I don't recommend it. I've used IRFZ34s and BUZ11 as outputs. In fact, I've seen Rockford substitute all manner of devices in those amps. Even some 15N06's. |
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| ALW |
I've already subbed parts for both the PSU switching Mosfets and the push-pull drivers to them, after some data sheet comparisons, certainly that bit isn't too critical - the PSU is open-loop and unregulated.
The schematic details many of those production mods though, revision A was 01-94, rev X was 12-95.
A lot of changes during a relatively short life.
Andy.
P.S. My interest in the duals was more of a generic one, I've not seen many dual matched SMD bipolars, I was curious as to what they might be to see if they would be of interest to future designs. |
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