I have this unit and have a few issues. I was hoping to get some coaching here on where to start checking for issues.
First, when plugged in, it comes on and will not turn off at switch. All lights seem to work. I have been trying to find a replacement switch, but not even sure what I am looking for. I have owners manual and service manual.
Second, when plugging in cd player into fixed input, I get no sound from speakers an A or B.
Does this unit require a pre-amp? Can ot work alone between a cd player and speakers?
It could be as simple as a fuse, but don't want to start working inside until I have a better understanding. I was told the unit worked before being put in storage 15 years ago. It was stored inside house.
What is a good ohm meter, for not much money, as I may only use for this?
I have installed car stereos and home theaters, so I have a little knowledge, but don't know how to fix electronics. I can follow instructions well.
I would like to start with getting a new switch, unless this could be another issue, and ohm meter.
Thanks
First, when plugged in, it comes on and will not turn off at switch. All lights seem to work. I have been trying to find a replacement switch, but not even sure what I am looking for. I have owners manual and service manual.
Second, when plugging in cd player into fixed input, I get no sound from speakers an A or B.
Does this unit require a pre-amp? Can ot work alone between a cd player and speakers?
It could be as simple as a fuse, but don't want to start working inside until I have a better understanding. I was told the unit worked before being put in storage 15 years ago. It was stored inside house.
What is a good ohm meter, for not much money, as I may only use for this?
I have installed car stereos and home theaters, so I have a little knowledge, but don't know how to fix electronics. I can follow instructions well.
I would like to start with getting a new switch, unless this could be another issue, and ohm meter.
Thanks
Nice amplifier, a bit of a monster for your first repair project. You should be getting sound with a CD player. Fuses and relays are are the best place to start.
I did a few tests.
I connected cd player to variable input, had only tried fixed before. I played cd and using left and right attenuators, I could get meters to move accordingly.
I can switch from stereo to mono and the correct front lamp lights up also.
I need to find some speaker wire and try speakers again.
I connected cd player to variable input, had only tried fixed before. I played cd and using left and right attenuators, I could get meters to move accordingly.
I can switch from stereo to mono and the correct front lamp lights up also.
I need to find some speaker wire and try speakers again.
Perhaps you should first know what the amplifier produces before connecting that to a speaker load. If there is a significant DC fault, you not only risk frying the speakers but do further damage to the power amplifier(s).
It's easy enough to test even if you only have the basic instruments like a multimeter, but preferably a digital type. Simply remove all inputs, turn the volume control down to zero or remove the links between the pre and power amplifiers on the rear (if there are any). Obviously, speakers should not be connected at this point either.
Then measure the DC voltage between the speaker output terminals of each channel. Ideally, it would be set to a stable zero volts but an offset of as much as +/-100mV will not cause harm and will likely be adjustable down to less than +/-10mV, which is better than specified, quite acceptable for an old design, and what many of us would realise is fine in the process of refurbishing an old amplifier.
It's easy enough to test even if you only have the basic instruments like a multimeter, but preferably a digital type. Simply remove all inputs, turn the volume control down to zero or remove the links between the pre and power amplifiers on the rear (if there are any). Obviously, speakers should not be connected at this point either.
Then measure the DC voltage between the speaker output terminals of each channel. Ideally, it would be set to a stable zero volts but an offset of as much as +/-100mV will not cause harm and will likely be adjustable down to less than +/-10mV, which is better than specified, quite acceptable for an old design, and what many of us would realise is fine in the process of refurbishing an old amplifier.
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I should have replied on multimeter choices by saying that any type should be OK but there is a limit to how low a voltage an analog meter can measure reliably. 10mV is very small and an analog or electro-mechanical meter mechanism would need to be an expensive one to read it correctly so a digital type would likely be more economical.
Brands and quality vary hugely and the prices asked vary from country to country and between Internet platform sites too. Even so, I found a real bargain in an ANENG 8009 model that is surprisingly easy to use and read with plenty of accuracy. It's backlit too but uses cheap batteries because for me, 9V batteries would have cost near half the price of the meter! It's actually quite small but quite good quality and has plenty of features for the price. I have no connection to any seller of these, other than as a happy customer. Have a look at a teardown anyway: ANENG AN8009 Test + Teardown - YouTube
Brands and quality vary hugely and the prices asked vary from country to country and between Internet platform sites too. Even so, I found a real bargain in an ANENG 8009 model that is surprisingly easy to use and read with plenty of accuracy. It's backlit too but uses cheap batteries because for me, 9V batteries would have cost near half the price of the meter! It's actually quite small but quite good quality and has plenty of features for the price. I have no connection to any seller of these, other than as a happy customer. Have a look at a teardown anyway: ANENG AN8009 Test + Teardown - YouTube
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If protection is engaged, You have to measure before the protection relay.
Do You hear the relay clicking when powered ?
I have a 2' section of 18g speaker wire and I borrowed a multimeter from a friend today.
https://www.homedepot.com/p/Klein-Tools-600V-Auto-Ranging-Digital-Multimeter-MM400/206517333
What setting do I use?
Also I will verify this tomorrow, but when I was testing meters, I seemed to of have a slight static feel when touching the unit.
If anyone wants to have a facebook or zoom video chat while I do this, I would appreciate that.
https://www.homedepot.com/p/Klein-Tools-600V-Auto-Ranging-Digital-Multimeter-MM400/206517333
What setting do I use?
Also I will verify this tomorrow, but when I was testing meters, I seemed to of have a slight static feel when touching the unit.
If anyone wants to have a facebook or zoom video chat while I do this, I would appreciate that.