Hi all! My Marantz 1030 is misbehaving, and has a constant loud noise on the left channel. It´s there with volume at 0, I´ve attached a little video to demonstrate.
YouTube
Here´s a schematic, if that helps anything: Schematic Diagram - Marantz 1030 Service Manual [Page 16]
I´m new to amp repair, I´ve made guitar effects pedals, so I (semi) know how to read a simple schematic and solder, but I don´t really know where to start here, so any help or resources would be greatly appreciated!
YouTube
Here´s a schematic, if that helps anything: Schematic Diagram - Marantz 1030 Service Manual [Page 16]
I´m new to amp repair, I´ve made guitar effects pedals, so I (semi) know how to read a simple schematic and solder, but I don´t really know where to start here, so any help or resources would be greatly appreciated!
Manualslib doesn't work for me as my blockers block it from getting info from me.
Eservice info does work .
With the volume at zero its more likely the fault is nearer the output but that is just a percentage guess, is it still working but accompanied by this noise?
Eservice info does work .
With the volume at zero its more likely the fault is nearer the output but that is just a percentage guess, is it still working but accompanied by this noise?
Could be a bad solder joint or resistor. Look carefully with a light, and a magnifying glass if necessary.
Don't start replacing transistors, that is much less likely to be the problem.
Is the noise stopped by removing the pre-out/main in jumpers on the back (with the unit turned off)?
If not, it is in the power amplifier and will not be easy to troubleshoot in your case.
If the noise is gone with the jumper cables removed, this problem will be much easier to find.
Once located to this or another stage, you could try freeze spray on one pcb component at a time.
Use some junk speakers for this purpose, or your main speakers end up as junk.
Max Pro FR-777-777 Freeze Spray 10 oz.
Marantz 1030 - Manual - Stereo Integrated Amplifier - HiFi Engine
Don't start replacing transistors, that is much less likely to be the problem.
Is the noise stopped by removing the pre-out/main in jumpers on the back (with the unit turned off)?
If not, it is in the power amplifier and will not be easy to troubleshoot in your case.
If the noise is gone with the jumper cables removed, this problem will be much easier to find.
Once located to this or another stage, you could try freeze spray on one pcb component at a time.
Use some junk speakers for this purpose, or your main speakers end up as junk.
Max Pro FR-777-777 Freeze Spray 10 oz.
Marantz 1030 - Manual - Stereo Integrated Amplifier - HiFi Engine
Last edited:
Yes, it still has signal going through, and it´s very loud/gained, much louder than the right channel.
Unfortunately, my amp doesn´t have the jumper cables in the back, so I can´t check it that way... I will look for something gone wrong, what should I be looking for specifically?
Preamp and phono appear to be populated with 2SC458LG's which in some circles (AK) has a "shoot on site" (=preemptive replace). Suggest try a short burst of freeze spray on the preamp transistors and note effect, allow 20 seconds for transistor to recover before moving to next.
I got a tip in another group, and I´ve had a little progress - because the L channel is very noisy and gained (when I put signal through it, it´s much louder than R), I was told to measure L and R between the preamp and poweramp, where the voltages were pretty similar, and then by the speaker outputs where they were 1.5V R and 25V left. So the problem is probably in the poweramp. Should I go ahead and buy some freeze spray, and try it on the components? Nothing looks very bad visually on the poweramp board. But it does smell very burnt when i turn it on.