Gint F Posted March 8, 2014 Share Posted March 8, 2014 I have a similar problem with the power supply on my iFi not lighting up. Measured 118V good at plug, and after switch. No fuses ever blown. MOV1 intact. Measured 1.7W on primary windings (Red) and 0.5W on secondary coil (yellow / brown), so transformer appears intact. Replaced 25V 4700uF cap with generic brand (Nichicon ordered, but wasn't in stock) as it was bulged and leaking. Replaced all 4 35V 4700uF caps with new Nichicons as two of four tested as short. Still no light or sound. Should I take the amp apart and dig for the rectifier next? Quote Link to comment Share on other sites More sharing options...
minermark Posted March 8, 2014 Share Posted March 8, 2014 I have a similar problem with the power supply on my iFi not lighting up. Measured 118V good at plug, and after switch. No fuses ever blown. MOV1 intact. Measured 1.7W on primary windings (Red) and 0.5W on secondary coil (yellow / brown), so transformer appears intact. Replaced 25V 4700uF cap with generic brand (Nichicon ordered, but wasn't in stock) as it was bulged and leaking. Replaced all 4 35V 4700uF caps with new Nichicons as two of four tested as short. Still no light or sound. Should I take the amp apart and dig for the rectifier next? Sounds to me like a voltage surge in the house current, tends to cook things. 1 Quote Link to comment Share on other sites More sharing options...
minermark Posted March 8, 2014 Share Posted March 8, 2014 A little thing I picked up awile back, we all like audio, we all like quality, buy one simple thing to protect your stuff, APC backup, no it's not going to power your hifi during a black out, but it has the best to date circuit protection. 1 Quote Link to comment Share on other sites More sharing options...
Gint F Posted March 10, 2014 Share Posted March 10, 2014 What should the output voltage be on the power supply, on which pins? Quote Link to comment Share on other sites More sharing options...
001 Posted March 11, 2014 Share Posted March 11, 2014 (edited) First things first. Make sure you used a "slow blow" or "time lag" fuse. After that I can help you on a few troubleshooting scenarios. i realize this is an old thread, but shouldn't it be a fast blow fuse for delicate electronics like a sub amp etc? every amp fuse i have seen (adcom, def tech etc) specifically says to use fast blow. slow blow or time lag dont break the circuit fast enough & can allow damage to other things upstream from the fuse. these speakers may be different, but adcom amps & many others insist on fast blow. Edited March 11, 2014 by klipschfancf4 Quote Link to comment Share on other sites More sharing options...
Gint F Posted March 11, 2014 Share Posted March 11, 2014 Can the subwoofer be used without the iPod control dock? Quote Link to comment Share on other sites More sharing options...
Gint F Posted March 13, 2014 Share Posted March 13, 2014 Does anyone have the pinouts for the DIN plug? Quote Link to comment Share on other sites More sharing options...
Andy W Posted April 22, 2014 Share Posted April 22, 2014 First things first. Make sure you used a "slow blow" or "time lag" fuse. After that I can help you on a few troubleshooting scenarios. i realize this is an old thread, but shouldn't it be a fast blow fuse for delicate electronics like a sub amp etc? every amp fuse i have seen (adcom, def tech etc) specifically says to use fast blow. slow blow or time lag dont break the circuit fast enough & can allow damage to other things upstream from the fuse. these speakers may be different, but adcom amps & many others insist on fast blow. It all depends on the application. In this case, the fuse is ahead of the main power supply transformer and there is a large surge of current (50-60 Amps on average if memory serves) when the empty power supply charges up when the switch is turned on. Remember: the purpose of a fuse is not always to protect components - that is sometimes secondary, more often it's there to protect you (from electrical shock or fire) in the rare case of abuse, insulation failure, or a component failure that could cause and electric shock, fire hazard, or insulation failure, and all this is the subject of inspection and testing at the safety labs that allow the use of the the NRTL logo (i.e. a UL mark or similar). Also "fast" is relative. If there is problem, the fuse will blow very quickly, since it is appropriately rated for the actual current draw of the system. If you use a "fast blow" fuse large enough to survive the inrush current, then it won't blow fast enough when a real problem occurs and you end up with a real problems - internal wiring melted, transformer insulation melted - lots and lots of smoke and a potential for flame. On the other hand a "time lag" or "slow blow" fuse allows the harmless inrush current (over in a cycle or two of the power line frequency) to pass and yet will blow very quickly and uneventfully in the even of a component failure like a power supply cap or rectifier. Fast blow fuses are typically used on the DC rails of an amplifier between the power supply and the amplifier output devices (transistors) in an effort to protect them. Yet in the real word the output devices have an uncanny ability to protect the rail fuses from harm. Quote Link to comment Share on other sites More sharing options...
coletrain09 Posted June 30, 2014 Share Posted June 30, 2014 I also have the iFi and it has performed great for many years (2006?). Recently the sound became very distorted. As best I can tell, it is as if very little power is being directed to the satellites and the subwoofer is at maximum. The subwoofer adjustment is still functioning but at the lowest setting it is far too much bass to even recognize the music. I pulled the back panel off and there is no obvious capacitor issue nor any obvious burning or damage on the boards. I inspected the woofer cone after removing the front grill and it looks fine. Any advice as to what may be causing this issue? Thanks, Cole Quote Link to comment Share on other sites More sharing options...
Gint F Posted June 30, 2014 Share Posted June 30, 2014 first, have you measured resistance on the primary and secondary coil windings? Next, it's not always the caps on the power supply that go bad. I dug deeper and found a leaky cap on the amp board. Quote Link to comment Share on other sites More sharing options...
coletrain09 Posted June 30, 2014 Share Posted June 30, 2014 Hi Gint. I'm not certain I've measured the right things. The large coil, about 4" in diameter, measures 0.6 if I disconnect the brown lead and measure on those 2 points (since the coil is not exposed, wrapped in plastic). There is a smaller coil, about 1" in diameter, on the board that has a fuse on it. That coil doesn't measure anything. Quote Link to comment Share on other sites More sharing options...
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