Sorry. I missed this.
One problem that I see is that there is inconsistent readings on pin 5. It connects to the point where R63 and R73 connect. When the amp shuts down, the voltage isn't the same on the two resistors as well as pin 5. Were the readings in error or is the problem causing the inconsistent readings causing the shutdown?
One problem that I see is that there is inconsistent readings on pin 5. It connects to the point where R63 and R73 connect. When the amp shuts down, the voltage isn't the same on the two resistors as well as pin 5. Were the readings in error or is the problem causing the inconsistent readings causing the shutdown?
I think the readings drift because the amp is slowly recovering from what shut it down.Taking the reading is a challenge because the amp recovers very fast when i remove the bottom cover.
I pull both thermistor just to make sure they not triggering the shutdown.Maybe an IC is thermally shunting down?
I pull both thermistor just to make sure they not triggering the shutdown.Maybe an IC is thermally shunting down?
Went back to this amp today.I see good gate signal on all PS FET.
SG3526
working --- shutdown
1:4.96 ----- 4.23
2:3.778 ---- 0.002
3:4.22 ------ 0.109
4:4.69 ------- 0.008
5:4.18-------- 0.022
6:0.001------- 0.000
7:0.001 ------ 0.000
8:4.33 --------3.365 pulsing to about 3.772
9:3.735 ------ 3.082
10:1.995 ----- 1.794
11:0.003------- 0.002
12:4.63 -------- 4.15
13:6.66 -------- 0.001
14:15.65 -------12.59
15:0.001 ------- 0.000
16:6.67 --------- 0.001
17:15.67 --------12.59
18:4.96 ----------4.33
SG3526
working --- shutdown
1:4.96 ----- 4.23
2:3.778 ---- 0.002
3:4.22 ------ 0.109
4:4.69 ------- 0.008
5:4.18-------- 0.022
6:0.001------- 0.000
7:0.001 ------ 0.000
8:4.33 --------3.365 pulsing to about 3.772
9:3.735 ------ 3.082
10:1.995 ----- 1.794
11:0.003------- 0.002
12:4.63 -------- 4.15
13:6.66 -------- 0.001
14:15.65 -------12.59
15:0.001 ------- 0.000
16:6.67 --------- 0.001
17:15.67 --------12.59
18:4.96 ----------4.33
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I think the IC may be defective. I checked the voltage with and without B+ as well as with the shutdown pin grounded and the regulated output on pin 18 was a constant 5.01v.
It could be that the regulated voltage is being pulled down, causing the IC to shutdown but that wouldn't make the IC overheat?
Do you have another IC to replace this one?
If you replace it, you may have to temporarily remove R34 if the new IC won't function.
It could be that the regulated voltage is being pulled down, causing the IC to shutdown but that wouldn't make the IC overheat?
Do you have another IC to replace this one?
If you replace it, you may have to temporarily remove R34 if the new IC won't function.
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