Don't buy one.
The IC didn't fail in the most common way (you checked the output stage). You checked everything else in that part of the circuit.
A couple of things you could try. Completely disconnect from the IC by removing D33 and R157.
You could also try paralleling a second capacitor across the caps in that area. They are low in value so even a 0.1 or 0.01 would be more than enough to tell us if you possibly have a bad cap. It's unlikely but there aren't many things left to try.
The IC didn't fail in the most common way (you checked the output stage). You checked everything else in that part of the circuit.
A couple of things you could try. Completely disconnect from the IC by removing D33 and R157.
You could also try paralleling a second capacitor across the caps in that area. They are low in value so even a 0.1 or 0.01 would be more than enough to tell us if you possibly have a bad cap. It's unlikely but there aren't many things left to try.
With D33 and R157 removed the amp powers up with no protect. IC4 has 15.1v DC on pin 10. IC2 has 0v on pin 10. No PWM on any pin of either IC
Pure DC? No square wave?
Where was the black meter probe when measuring pin 15?
What are you using to measure the volage?
Where was the black meter probe when measuring pin 15?
What are you using to measure the volage?
Check the high-side output sections of the ICs like you did for the low-side. Pins 14, 15 and 16.
Same battery powered scope as in post #30?
Weren't you having trouble with its voltage readings?
Same battery powered scope as in post #30?
Weren't you having trouble with its voltage readings?
Yes it's the same scope, I got a new probe for it and re-calibrated it. It's confirmed accurate to my DMM now
I'll test shortly and give you the voltages on those pins on IC2 and IC4
I'll test shortly and give you the voltages on those pins on IC2 and IC4
IC2
Pin 14: 12.8v DC
Pin 15: 12.8v DC
Pin 16: 15.2v DC
IC4
Pin 14: 11.2v DC
Pin 15: 11.2v DC
Pin 16: 15.2v DC
Pin 14: 12.8v DC
Pin 15: 12.8v DC
Pin 16: 15.2v DC
IC4
Pin 14: 11.2v DC
Pin 15: 11.2v DC
Pin 16: 15.2v DC
What you're doing here is basically what you're doing when you check the output transistors in an amp. ICs can fail in other ways but this type of failure (shorted internal transistors) is easy to check. The 8244 datasheet didn't have a good diagram. This is from a different driver IC. Note how each drive circuit is much like the output stage of an amplifier.
My mistake on post #116. You check:
14-15
14-16
15-16
My mistake on post #116. You check:
14-15
14-16
15-16
Attachments
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IC2
Pin 14 to 15: 10.99k ohms
Pin 14 to 16: 1.02m ohms
Pin 15 to 16: 1.05m ohms
IC4 meters identically
Pin 14 to 15: 10.99k ohms
Pin 14 to 16: 1.02m ohms
Pin 15 to 16: 1.05m ohms
IC4 meters identically