My Aleph 3 has been recapped by myself a few years ago. It has been a great pair with my Philharmonitor. However, since this winter I notice sometime the soundstage can be shifted to far right and I realized that the left channel must be faded, although there was still sound coming out of it.
The next time I turn it on, the problem went away, but recently I notice that the same problem came back again.
I have checked R106 and Z103 from the service manual, and the voltages (5.7V and 8.8V) are kind of within range (I didn't wait for the amp to fully warm up). There is no apparent burning of any components with some quick check. A thorough check will require removing some heat sinks.
I would appreciate some pointing to start the diagnosis. Thanks!!
The next time I turn it on, the problem went away, but recently I notice that the same problem came back again.
I have checked R106 and Z103 from the service manual, and the voltages (5.7V and 8.8V) are kind of within range (I didn't wait for the amp to fully warm up). There is no apparent burning of any components with some quick check. A thorough check will require removing some heat sinks.
I would appreciate some pointing to start the diagnosis. Thanks!!
cold solder joint somewhere
you must remove some heatsinks ....
prepare new thermal paste , lenses and patience
you must remove some heatsinks ....
prepare new thermal paste , lenses and patience
Thanks a lot for the quick hint, ZM!
So do I just carefully visual check all the joints? Or maybe check voltages at some strategic points to isolate which board first? From the service manual pdf I can only get a handful voltages to check. Maybe compare the same components of the left and right channels?
Thanks!!
So do I just carefully visual check all the joints? Or maybe check voltages at some strategic points to isolate which board first? From the service manual pdf I can only get a handful voltages to check. Maybe compare the same components of the left and right channels?
Thanks!!
do whatever you can - comparing good and bad channel
these voltages from SM are reference and you can't measure much more
in any case - compare voltages across source resistors , check voltages at input CCS (third small mosfet and associated resistors)
take small plastic stick (pencil size) and gently press each component ......maybe you'll find culprit that way
these voltages from SM are reference and you can't measure much more
in any case - compare voltages across source resistors , check voltages at input CCS (third small mosfet and associated resistors)
take small plastic stick (pencil size) and gently press each component ......maybe you'll find culprit that way
I took out the heatsink fins and checked for soldering points. Sure enough the first thing I touched showed the culprit. Last time when I recap my Aleph 3 (many years ago), some new cap was too big to fit it so I have to had some pin-to-pin soldering. That was the point got disconnected after so many years of thermal cycles.😀
I resoldered it and cleaned the point with isopropenyl alcohol and hope it will not bother me for another 5~10 years. 🙄
ZM, thanks a lot for saving my Aleph 3 many times!!
I resoldered it and cleaned the point with isopropenyl alcohol and hope it will not bother me for another 5~10 years. 🙄
ZM, thanks a lot for saving my Aleph 3 many times!!
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