CVT3030 - permanent muted
Hello,
I am repairing an old CVT3030 and I have found that the mute feature is 'stuck', the FET's after the pre-amp stage is 'on' (Gain voltage is zero). I do have some schematics, but not for the headphones PCB board which seems to be involved in the mute feature. All supply voltages are ok and the pre-amp works fine.
Prior to the current situation I replaced a faulty zener diode ZD302 (causing the 15V supply fuses to blow).
Any comments and help is appreciated. Is the schematics for the headphone PCB available?
Regards,
- Lars
Comments
CVT3030 - down load CVT3030 Service Manual from AMC website
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Hi Lars,
We just uploaded CVT3030 Service Manual on AMC CVT3030as section of AMC website www.amchome.com
Please down load it for checking your unit. Please refer to Pre-Amp schematic of CVT3030 on P11 of 17 of the Service Manual and trace from gate of Q315 (J105) to power supply on all related circuitries for mute feature.
Hope above will help. Let us know if there will be any we can do further.
Cheers,
AMC Support Team
IEEE Group
www.amchome.com
CVT3030 Service Manual
Hi Lars,
CVT3030 Service Manual with Schematic of Headphones Amp was uploaded to www.amchome.com already.
Please note the mute signal connected to Headphone Amplifier is for muting Headphone Amp. As mentioned previously, the mute signal is from power supply voltage that you can find on Pre-Amp schematics.
All the Best,
AMC Support Team
IEEE Group
www.amchome.com