I guess "teat" means test, and test of if the LM3886 IC is still functional.
Measure the impedance (resistance) from the output pin and to the "+" and "-" pins, and from the "+" pin to the "-" pin (without power evidently). I can try the same tomorrow and we can compare the results. It is clearly not a full test but a good indication.
Measure the impedance (resistance) from the output pin and to the "+" and "-" pins, and from the "+" pin to the "-" pin (without power evidently). I can try the same tomorrow and we can compare the results. It is clearly not a full test but a good indication.
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a common failure is the output transistors so check output to rails for continuity. low impedance equals broke.
From pin 1+ to pin 3 op I get 11.42k
From pin 3 op to pin 4- I get .526 on 2k range
From pin 5+ to pin 3 op I get .583 on 2k range
From pin 4- to pin 5+ I get .445 on 2k range
From pin 1+ to pin 4- I get 1.861 on 2k range
Thanks
From pin 3 op to pin 4- I get .526 on 2k range
From pin 5+ to pin 3 op I get .583 on 2k range
From pin 4- to pin 5+ I get .445 on 2k range
From pin 1+ to pin 4- I get 1.861 on 2k range
Thanks
I am waiting on some solder wick to test out of circuit. On my dim bulb tester the light stays lit at a constant level so I guess they have a short.
Start by stating what is the problem you are trying to solve, if any.
Which are the symptoms which lead you to test an LM3886 to begin with?
No sensible answers possible until you answer that, sorry.
schematic
Hi a friend gave me Mackie s8 monitors to look at. He said that it blows its fuse after 20-30 seconds. I tested the caps with ESR and all seemed ok.
On dim bulb it doesn't dim.
Hi a friend gave me Mackie s8 monitors to look at. He said that it blows its fuse after 20-30 seconds. I tested the caps with ESR and all seemed ok.
On dim bulb it doesn't dim.
best way to get them out i found was to cut pins as high up as possible.
then heat up pin at pcb then either shake pcb or then grab top end of pin with long nose pliers.
however before replacing i would power it up to see if something else is wrong.
on my design the pads on top of the pcb were a little big and if the 3886 was pushed right down it would short on adjacent pin.
so i had to sit the 3886 up a bit.
then heat up pin at pcb then either shake pcb or then grab top end of pin with long nose pliers.
however before replacing i would power it up to see if something else is wrong.
on my design the pads on top of the pcb were a little big and if the 3886 was pushed right down it would short on adjacent pin.
so i had to sit the 3886 up a bit.
I have powered its power transformer without a load though the dim bulb and I could hear intermittent buzzing,crackling sounds it comes and goes .It is outputting the correct voltage though. What sort of value resistor would be good to load it?
I have metered the secondary and primary and compared the readings with the other working speaker and they are exactly the same
Thanks
I have metered the secondary and primary and compared the readings with the other working speaker and they are exactly the same
Thanks