Re: Testing Capacitors - VLoss Changed, why?
If you are interested, this is the service manual / circuit diagram, obtained from "Cambridge Audio" (as they have discontinued this model/version and replaced it with a newer one)....
Pizarro
New Member
Last Activity: 12-10-2021, 08:46 AM
Joined: 12-05-2021
Location: Surrey
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Re: Testing Capacitors - VLoss Changed, why?
The problem might be on one of the signal lines going into or out of one the chips (AK5358 , STA309A , R5F211A4 or STA516B ).
If I can figure out where I loose the audio signal, I can backtrack to see if one of the chips are broken or if there is a fault/short/floating-signal/etc on one of the lines.
Oh, I have also tried turning up the volume control (I even measured the pot to check that turning it did change its resistance).Last edited by Pizarro; 12-07-2021, 05:48 PM.Leave a comment:
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Re: Testing Capacitors - VLoss Changed, why?
The problem is with a "Cambridge Audio minix x200 CA609 Digital Subwoofer", not producing sound.
I do have a copy of the service manual, but that is just an exploded diagram of its parts and the circuit schematics for both the power board and amplifier board.
The audio signal can correctly pass though from "audio in" to "audio out" (so it is not the signal source), but something with the powered sub.
The power led lights up ok, but no sound is being generated....Last edited by Pizarro; 12-07-2021, 05:21 PM.Leave a comment:
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Re: Testing Capacitors - VLoss Changed, why?
FYI... Comparing the service manual schematics with the circuit board components....
The schematic states they caps are "330uF 16V", but they built it with "330uF 10V" caps.
The under rated caps are the one with aprox 15% vloss on them.Leave a comment:
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Re: Testing Capacitors - VLoss Changed, why?
FYI... The meter is a cheap and nasty "Draper 60792 Digital Multimeter".
Useful for checking to see if the house electrics are live or how dead my batteries are, but not really designed for analyzing digital logic circuits.
I have ordered myself a "JYE Tech Wave2 Portable Oscilloscope DIY Kit", and will come back to trying to fix my subwoofer, after it arrives.
Thanks for the info and the helpLeave a comment:
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Re: Testing Capacitors - VLoss Changed, why?
I'm not sure my meter is accurate enough to measure the ripple(noise).
e.g. the +5v line measures 4.9v (dc) and 10.0v (ac). So I would guess that the ripple would be +-0.1v ?
The 10v makes sense, as I assume the meter is measuring the peak voltage, but with it set to AC it assumes that it is half of a "sin wave" (so it doubles the value). Flipping the leads causes it measure 0.0v (actually it flips between "0.0" and "-0.0").Leave a comment:
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Re: Testing Capacitors - VLoss Changed, why?
Thanks for the info. It was already not working, so I'm not fussed if I have broken something (else).
I will probably replace the caps with some new ones, and see if that helps.
They are part of the circuit generating the +3v and +5v lines, and those seem to measure between 13% and 15% VLoss across the cap (in circuit).
I'm hoping that the problem with the rest of the circuit is just noisy power. As it seems to still be producing the voltage correctly (according to my cheap multi-meter).Leave a comment:
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Cambridge Audio minix x200 CA609 Testing Caps - VLoss Changed, why?
Hi,
I'm a noob trying to fix my sub-woofer.
I have obtained some simple tools and the circuit diagram, but have seen some odd behavior with one/some of the capacitors.
The problem is I don't know enough, to know what terms I should be searching for (so I can understand what happened).
Issue:
I used a simple "multi-function Tested T7" to check some of the capacitors (in circuit). Specifically a "330uF 10V JWCO" electrolytic capacitor, with my tool stating it was:
"304uF ESR=0.39 VLoss=15%"... -
Re: New Members - please post your introductions here
Hi, I'm a noob trying to fix my subwoofer, looking for a little guidance and friendly advice.Leave a comment:
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