Sony TA 1150 loud static left channel

[markcally]

I recently got out of storage; put on new power cord and cleaned the push button switches; the unit worked fine until it got a little warmed up then loud cracking static comes out of left channel which cannot be volume adjusted at all; comes through headset as well so not the speaker connection; what is this noise coming from. mj

 

[Mark Tillotson]

Its after the volume control in one channel, probably a component on the left power amp section. Localizing intermittent problems can sometimes be done with a cool-spray or an insulated poking stick. Thermal or mechanical changes can affect the faulty part enabling it to be traced.


Are you happy/confident to work on the unit opened up and powered?

 

[wiseoldtech]

Anything mounted onto a heatsink, such as output transistors or regulators, and some power resistors, can have dry connections.
Over time, with the normal heating/cooling that happens, these become intermittent, and need to be touched up with fresh soldering.

 

[Ylli]

That unit uses 2SC632 transistors in the power amp input differential pair. The 2SC632 is on a list of transistors with a known high failure rate. The failure mode includes noise. That is where I would start looking.