Hi everyone, this is my first post here.
I have a Harmon Kardon 430 receiver that came to me recapped and in very good condition.
After about a year of consistent use, I was listening to music at a reasonable volume one night when the sound started to fade and a static fuzzing and popping noise began fading in and out. At the same time I got a whiff of that distinctive "burning electronics" smell and immediately unplugged it.
After opening it up and examining it from the bottom, I noticed the middle fuse and the inline resistor were fried:
Resistor is hiding beneath some melted tubing in the top right.
The fuse is FU1 in the manual. It connects to Transformer 1 on one side, and (via the now fried inline resistor labeled R9) to a board labeled Rectifier A on the other:
or zoomed out
I ordered up a new 0.5Amp 250V slow-blow fuse, and a 8.2ohm 1/2W resistor, desoldered the old one and replaced the parts.
After plugging it in and turning on the power, probably to no one here's surprise, the burning smell was back and the new resistor started overheating within a few seconds. (The fuse did not blow, but it turned white which makes me think it got part-way through the "slow" blow.
That's where I am today, I know the basics of electronics and how to solder and measure voltage/resistance and I am eager to learn, but I am a total novice when it comes to these receivers.
Does the failure I experienced indicate a specific problem I can look into? Any tips on where to start? Anything would be much appreciated.
-Andy
I have a Harmon Kardon 430 receiver that came to me recapped and in very good condition.
After about a year of consistent use, I was listening to music at a reasonable volume one night when the sound started to fade and a static fuzzing and popping noise began fading in and out. At the same time I got a whiff of that distinctive "burning electronics" smell and immediately unplugged it.
After opening it up and examining it from the bottom, I noticed the middle fuse and the inline resistor were fried:
Resistor is hiding beneath some melted tubing in the top right.
The fuse is FU1 in the manual. It connects to Transformer 1 on one side, and (via the now fried inline resistor labeled R9) to a board labeled Rectifier A on the other:
or zoomed out
I ordered up a new 0.5Amp 250V slow-blow fuse, and a 8.2ohm 1/2W resistor, desoldered the old one and replaced the parts.
After plugging it in and turning on the power, probably to no one here's surprise, the burning smell was back and the new resistor started overheating within a few seconds. (The fuse did not blow, but it turned white which makes me think it got part-way through the "slow" blow.
That's where I am today, I know the basics of electronics and how to solder and measure voltage/resistance and I am eager to learn, but I am a total novice when it comes to these receivers.
Does the failure I experienced indicate a specific problem I can look into? Any tips on where to start? Anything would be much appreciated.
-Andy
