The solder connections are often a good indication of what's been flow soldered and what's been hand soldered.
You may also be able to see the impression of the TO-220 transistors on the sil pads if they were originally in the amp.
You may also be able to see the impression of the TO-220 transistors on the sil pads if they were originally in the amp.
I cant tell since the sil pad was not orginal.. And also really couldnt tell if the solder was orginal ..
The guy sid he had someone fix it before..
So i will just put it back to the other outputs..
The orginal outputs are the SSP45N20A's So will the IRF3415's work in this ?
The guy sid he had someone fix it before..
So i will just put it back to the other outputs..
The orginal outputs are the SSP45N20A's So will the IRF3415's work in this ?
I don't know if the 3415s would work. They may work if the rail voltage never exceeds ±75v. The IRFP260N is readily available.
Ok i replaced the outputs in this amp i put them back to the SSP45N20A's
Also replaced all drivrs for the outputs...
Amp still has 70 volts on output terminals.. Thats measured directly across them..
Any ideas where to look next ?
Also replaced all drivrs for the outputs...
Amp still has 70 volts on output terminals.. Thats measured directly across them..
Any ideas where to look next ?
I don't have any information on this amp. I'd need a MUCH better photo to help.
Read the photo section of the basic repair page. The camera that I used there was a very old Nikon. I'm sure that the S3000 can do much better if you take the time to learn to use it.
Read the photo section of the basic repair page. The camera that I used there was a very old Nikon. I'm sure that the S3000 can do much better if you take the time to learn to use it.
If Q22 is connected to the bases of the drivers for the high-side FETs, pull it. Does that eliminate the DC?
What is the DC voltage across pins 1 and 3 of the high-side FETs?
If you have two meters, connect a meter across the speaker terminals while you're measuring the DC voltage across the legs of the FET to see if the DC voltage across the speaker terminals drops.
If you have two meters, connect a meter across the speaker terminals while you're measuring the DC voltage across the legs of the FET to see if the DC voltage across the speaker terminals drops.
If you have less than 1v and you still have 70v on the speaker terminals, you either have shorted/leaky FETs or something else is shorted to the positive rail.
With all of the outputs removed I get 81 volts on the output terminals still...
Would a shorted inductor cause this and still make the amp idle fine or do i need to look at other cause's?
Would a shorted inductor cause this and still make the amp idle fine or do i need to look at other cause's?
Unless the inductor is shorting to the board, it cannot cause there to be DC on the speaker terminals.
If you connect a dummy load resistor across the speaker terminals, does the amp draw excessive current or does the DC simply drop to 0v?
If you connect a dummy load resistor across the speaker terminals, does the amp draw excessive current or does the DC simply drop to 0v?
If i connect a 1 ohm resistor across the speaker terminals the DC goes away and amp still idles fine..
That would seem the indicate that something is leaking current and not shorted. Is there any leaked electrolyte on the board?
What is the rail voltage?
What is the driver voltage (emitter of Q20)?
What is the rail voltage?
What is the driver voltage (emitter of Q20)?
Ok something is not right with this amp now..
I have - 70 volts of rail but only 5.6 volts of positive rail and now i have 5.6 volts on the output terminals..
Im thinking the rectifer is bad..
I have - 70 volts of rail but only 5.6 volts of positive rail and now i have 5.6 volts on the output terminals..
Im thinking the rectifer is bad..
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