Sounds like high current arcing in the bulb. That can cause voltage transients due to the stray inductance and capacitance of the house wiring. The current could have reach 10--100A or so, with high frequency components due to the arcing, then quenched suddenly. Such shorts typically blow several fuses/breaker simultaneously. The effect of voltage transients on other mains equipment can easily be expensive, just as with lightning events. This is why expensive equipment has mains filtering, typically built into an IEC socket.
Does this amp have any mains conditioning?
Does this amp have any mains conditioning?
No i dont see any. (2 pictures below)
I only use the CD player in the MR2020, the tuner and power/preamp are not used.
I have made a digital output from the DAC and only use the MR2020 to play CD.
But no funktions are working and i think the powersupply has more problems than the solved one
I dont care if the tuner and amp are working or not, i´am not using that
I will try to measure the V across all the Zener-diodes later, and the transistors
From gnd to 5,6 V pin i measure 5,3 V
From gnd to -27 V pin i measure -27,1 V
But i dont know what the V should be at F1 and F2
I only use the CD player in the MR2020, the tuner and power/preamp are not used.
I have made a digital output from the DAC and only use the MR2020 to play CD.
But no funktions are working and i think the powersupply has more problems than the solved one
I dont care if the tuner and amp are working or not, i´am not using that
I will try to measure the V across all the Zener-diodes later, and the transistors
From gnd to 5,6 V pin i measure 5,3 V
From gnd to -27 V pin i measure -27,1 V
But i dont know what the V should be at F1 and F2
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F1 and F2 provide low-voltage, relatively high current 60Hz AC (typ 2 to 4V) for the display tube, centered around the -22V (5V closer to ground than the grids) provided by the regulator you repaired, Q802.
If all items in the display are lit up, the microprocessor isn't scanning; that would be consistent with the 'no response to buttons' symptom. If the giant power spike killed your Mechancon uP, you've probably heard your last CD from it.
But there is a chance that the uP's power is just down, too. You mentioned that you mod'ed a digital out for the player -- so, maybe you have a 'scope? Still some things you could check before declaring it an *organ donor*.
Regards,
Rick
If all items in the display are lit up, the microprocessor isn't scanning; that would be consistent with the 'no response to buttons' symptom. If the giant power spike killed your Mechancon uP, you've probably heard your last CD from it.
But there is a chance that the uP's power is just down, too. You mentioned that you mod'ed a digital out for the player -- so, maybe you have a 'scope? Still some things you could check before declaring it an *organ donor*.
Regards,
Rick
R808 open or D813 short ?The voltage out of F1 and F2 measure the same as -27 V så there is a big damage somewhere
Mona
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