Amp was bought as going into protect after power up.
Here is what I have for info
Input fets:
All gate pins have 5.4V.
All drain pins have (same voltage coming into the amp)11.9v.
All source pins have 4-7mv.
Output fets:
all pins have nothing on them, with signal or no signal coming in(Ill have to double check these numbers but I'm pretty sure there is none)
All fets check out
Notes:
If I put a little bit of bend or twist in the board by putting a little pressure on a corner of the board a high pitch noise comes from around the big 100v caps.
3 of the 6 input fets heat up hot on the right side of the board but not the back. I've moved the fets around and still all the fets on the right side only warm up.
The amp doesn't go into protect at all for me so I have no idea why there is no output.
Here is what I have for info
Input fets:
All gate pins have 5.4V.
All drain pins have (same voltage coming into the amp)11.9v.
All source pins have 4-7mv.
Output fets:
all pins have nothing on them, with signal or no signal coming in(Ill have to double check these numbers but I'm pretty sure there is none)
All fets check out
Notes:
If I put a little bit of bend or twist in the board by putting a little pressure on a corner of the board a high pitch noise comes from around the big 100v caps.
3 of the 6 input fets heat up hot on the right side of the board but not the back. I've moved the fets around and still all the fets on the right side only warm up.
The amp doesn't go into protect at all for me so I have no idea why there is no output.
Do you know what the chip # is and a good source for it is? If not Ill look tomorrow after I get off.
You are correct. The ones i find are on simi. The ones on the board are fairchild. Seem to have the same data sheet. Will that hurt anything? Also is there anywhere else i should check before ordering parts so i dont have to do multiple orders?
So this one (bjt) i think what it is stopping the whole output side of the board not to work.
I got the chip off successfully. Well sorta, lifted the base pad. So i ordered the part and we will see. Do you happen to know where the base pin connects to so i can make a bridge wire
See I already got that and I'm hoping it's not just a test point. If you look at this picture there is also copper trace above it I found. It's really close to where the pad was so I'm wondering if it connects up there also.
Also is it normal that there is 1v or so dc on the output with 40hz going in with that chip out? It has me worried. Without 40hz signal there is like less then 150mv dc on the output. I didn't test that long because I didn't want to damage anything.
I can't tell you what you would have on the output. That IC powers the drive circuit.
The copper near the trace is likely copper pour in the layout. If so, it's a fill that goes everywhere there isn't a trace. It's often connected to ground.
The attached image shows a board with a green mask instead of black.
The copper near the trace is likely copper pour in the layout. If so, it's a fill that goes everywhere there isn't a trace. It's often connected to ground.
The attached image shows a board with a green mask instead of black.
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