Across the speaker terminals I am getting -1.5vdc on both. I didn't understand where you wanted me to put the black probe and measure the resistor and the cap that I jumped. However by putting the black probe on power grd, I was getting no voltage
Has any work ever been done to this amp.
I wanted the black probe on the negative speaker terminal when measuring the voltage on the driver board.
I wanted the black probe on the negative speaker terminal when measuring the voltage on the driver board.
With the voltages I gave you the second time was from the speaker grd. It doesn't look like it. I looks like factory soldering.
It's a dental pick. It an other options are shown near the bottom of the 'know your meter' page.
I need accurate DC voltage readings from all pins of U205 on the driver board.USe the negative speaker terminal for the black probe. Clamp it down. Touching the screw head can be intermittent.
U205 LM6172im
1. -0.100
2. 0
3. 0
4. -5.175
5. -2.241
6. -0.108
7. .451
8. 5.905
Neg speaker terminal as grd ref
1. -0.100
2. 0
3. 0
4. -5.175
5. -2.241
6. -0.108
7. .451
8. 5.905
Neg speaker terminal as grd ref
There seems to be a couple of problems.
If those numbers are good, the IC appears to be defective. With the non-inverting input below the inverting input, the output should also be negative.
That said, pin 5 should be VERY near 0v.
Can you do the same on U208?
If those numbers are good, the IC appears to be defective. With the non-inverting input below the inverting input, the output should also be negative.
That said, pin 5 should be VERY near 0v.
Can you do the same on U208?
Perry I rechecked U205 and you were right, I miss printed and and shouldn't have placed the 2 in front of the decimal. Voltage on pin 5 in -.238
No sir, what I did was bend a meter lead tip, and put heat shrink on it and measured the op amps in board
Post a photo of the waveform on pin 5 of U205. Scope, center trace on reference, dc coupling, 2v/div and 10us.
Are you sure you were on the right point? I don't think the amplitude would have been more than about ±5v.
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