There will be more 9640s and the 3rd legs of all of the same transistors will be directly connected.
im just trying to figure out why the 640/9640 are getting warm just idling and all other fets and regulators are cold
I don't have any photos of your exact model but there's no way that you could possibly get them in the wrong locations with the photo and description I gave.
FETs typically heat up from either cross conduction (both banks on for a tiny fraction of the duty cycle) or because they're not being driven with enough voltage (would likely only affect one bank or the other and more likely when higher current was being driven through them). Excessive current could also cause it but that's not the case here.
FETs typically heat up from either cross conduction (both banks on for a tiny fraction of the duty cycle) or because they're not being driven with enough voltage (would likely only affect one bank or the other and more likely when higher current was being driven through them). Excessive current could also cause it but that's not the case here.
im wondering if maybe I should replace all resistors inline with the 9640/640's one thing I havnt tried yet
I am hoping around Christmas Ill have one
I removed the riser board near the rca jacks to check the voltage at the 9640/640s and there holding a steady 51.5 volts all of them 640's are - of course
I removed the riser board near the rca jacks to check the voltage at the 9640/640s and there holding a steady 51.5 volts all of them 640's are - of course
When measuring the drive voltage on transistors, you need to place the black probe on leg 3 and the red probe on leg 1.
It's difficult to make much of the readings unless something is really odd because there are so many variables.
It's difficult to make much of the readings unless something is really odd because there are so many variables.
I cant get into leg 3 with the heat sink in the way so I used the ground terminal
with the riserboard out near the rca jacks they don't seem to be getting hot or are they even being powered with that board out
with the riserboard out near the rca jacks they don't seem to be getting hot or are they even being powered with that board out
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Using the ground won't work when you need critical measurements like you do here.
You don't have to touch the leg. There a huge trace leading from the leg. Drill your probe through the solder mask into the trace or find something else connected to that trace very near the FET.
With the driver board out, the voltage 1-3 will be 0v.
You don't have to touch the leg. There a huge trace leading from the leg. Drill your probe through the solder mask into the trace or find something else connected to that trace very near the FET.
With the driver board out, the voltage 1-3 will be 0v.
I thought I might be able to locate what was fluctuating voltage wise with the riser board near the rca jack removed by checking the values throughout the board guess not
maybe the problem lies in the protect portion of the amp limiting the voltage throughout the whole amp?
That would be very difficult in a class D amp without a scope but if you could see the output pulsing on one of the preamp op-amps, it may be possible.
Hey Perry do you know if yg225n2 and yg225c2 should both have a closed loop between legs 1 and 3 each ?
Also Thermal has a closed loop not sure if that's normal
Also Thermal has a closed loop not sure if that's normal
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problem with this amp still have not been resolved hey Perry I thought I would take a shot at this one with my scope can you give me any suggestions on where to start
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