You were told about the importance of polarity in post #21. It is not possible to diagnose faults when supplied with wrong information. The information you supplied pointed to the loss of the negative supply rail.

Les.

 

You were told about the importance of polarity in post #21. It is not possible to diagnose faults when supplied with wrong information. The information you supplied pointed to the loss of the negative supply rail.

Les.

Hi
I am sorry . I

You were told about the importance of polarity in post #21. It is not possible to diagnose faults when supplied with wrong information. The information you supplied pointed to the loss of the negative supply rail.

Les.

I am sorry. I gave wrong information.
Carelessness of my fault.
Jeff

 

That's ok. We all make mistakes. You just did not know how to read your meter.
Your reading on IC501 pin-8 is still wrong. But that does not matter now.
It looks like IC501 is bad. We will just have to wait until you get it replaced.

When you do replace it, don't connect any speakers to the amplifier.
Measure all voltages on IC501 and report back before doing anything else.

 

That's ok. We all make mistakes. You just did not know how to read your meter.
Your reading on IC501 pin-8 is still wrong. But that does not matter now.
It looks like IC501 is bad. We will just have to wait until you get it replaced.

When you do replace it, don't connect any speakers to the amplifier.
Measure all voltages on IC501 and report back before doing anything else.

 

Thank you Sir,
I will follow your instructions.
I will let you know after installation.

Jeff

 

Hi
I am interested in integrated amplifier repair. Where do I start? Book from the art of electronics?
Study from web? Like oyvind Dahl?
Any suggestions will be very thankful.
Jeff

 

I think you should start by learning the basics about electricity. I am thinking about the sort of thing that would be taught in physics classes at school such as ohms law and the relationship between current voltage and power. I think when I was at school I think it was taught in the first few years of secondary school. (I am referring to the UK system when I was at school which was about 60 years ago.) (I still have some of my maths, physics and chemistry books from when I was at school.) I learned a lot from reading radio and electronics magazines and building projects from the magazines. I don't think it is sensible to specialise in one type of product. You could bias you learning towards analogue of digital electronics.

Les.

 

The "Teach in series" from Everyday Electronics magazines, or Elektor are very good..

 

Hi
I am interested in integrated amplifier repair. Where do I start? Book from the art of electronics?
Study from web? Like oyvind Dahl?
Any suggestions will be very thankful.
Jeff

Before even considering learning about repairing things it is VITAL to have an adequate understanding of electrical circuits. That would include understanding the relationships between voltage, current, resistance, and power. Next comes understanding a bit about basic circuit theory, and AC circuits.
But don't let the descriptions and names be a deterrent, because they are not very complicated, and basic math is all you will need to deal with.

But there is a publication to avoid, which is "Nuts and Volts", for the simple reason that it does not talk about theory, only about using little computer boards as a substitute for almost everything. That will leave a huge void in your knowledge area.

 

I think you should start by learning the basics about electricity. I am thinking about the sort of thing that would be taught in physics classes at school such as ohms law and the relationship between current voltage and power. I think when I was at school I think it was taught in the first few years of secondary school. (I am referring to the UK system when I was at school which was about 60 years ago.) (I still have some of my maths, physics and chemistry books from when I was at school.) I learned a lot from reading radio and electronics magazines and building projects from the magazines. I don't think it is sensible to specialise in one type of product. You could bias you learning towards analogue of digital electronics.

Les.

Hi
Very good advice. Thanks for that.
I am from Burma. But I live in Australia now.
I had finished physics in Burma.
Mostly all about Theory and text.
Not much for pratical.
I was average student.
After uni working as all different work. Not related to what I studied.
Now all forgot.
I even did not know how to read meter correctly.
Very shame.
Jeff

 

Hi
Very good advice. Thanks for that.
I am from Burma. But I live in Australia now.
I had finished physics in Burma.
Mostly all about Theory and text.
Not much for pratical.
I was average student.
After uni working as all different work. Not related to what I studied.
Now all forgot.
I even did not know how to read meter correctly.
Very shame.
Jeff

Developing any skill requires both study and practice. And while the electricity portion of a college level physics course is quite something, probably the material in a grade school level physics class would be adequate. Basic circuits and ohms law are the needed building blocks, followed by the fundamental circuit theory understanding, which reduces to the fact that in any closed circuit the sum of all the voltages is zero. That is where polarity becomes really important, otherwise the answer will not come out right. There should be books about that in a local library..

 

Developing any skill requires both study and practice. And while the electricity portion of a college level physics course is quite something, probably the material in a grade school level physics class would be adequate. Basic circuits and ohms law are the needed building blocks, followed by the fundamental circuit theory understanding, which reduces to the fact that in any closed circuit the sum of all the voltages is zero. That is where polarity becomes really important, otherwise the answer will not come out right. There should be books about that in a local library..

Thank you Sir.
Jeff