areus wrote:
Hi
Is this a popular failure on this drive? I have two (a 6L250S0, and a 6B200) ...with same defect: the combo (SMOOTH ver 1.2), the planar transistor (Q501), and some diode was defected (see the other topic). I had change all, and the drive ok. But only for a few minutes.... and the new combo heated up...and lot of smoke again:(
Conclusion: the preamp was good. So get a new PCB, and may it will be work again.
Nop.
He is touched the pcb, and he caused the short circuit or misscalibrated some circuit.
On your case is different.
You need to do a good soldering under the smooth chip, because the soldering is the heatsink for it!
And, you need to use the grey layer under the pcb to be able to cooling the pcb through the aluminium body.

If this is not helps, you need to measure more on the pcb...
Janos