groundpounder3000

[timwebb]

i got this to repair. just looking at it i noticed the output driver card was worked on. but two ic's were replaced and dont know if there right...this is how i got it. u1 and u2 have been changed

 

[timwebb]

i cant find a data sheet on the ic. d3 is shorted, i couldnt find a data sheet on it either.

 

[Perry Babin]

The ICs are right (IRS21844S or IR21844S will work).

Did you remove D3 to confirm that it was shorted?

 

[timwebb]

no i just tested d1 with diode check and it tested fine. d3 shorted with diode check. u2 also got hot when powered up.

 

[Perry Babin]

If the outputs failed, the driver IC that was driving the failed outputs has almost certainly failed as well.

 

[timwebb]

i got the amp with no output transistors in it.but from what i see that looks to be the cause.
i can tell by the soldering on the ic's that they have been replaced. some of the solder tabs are missing for the pins that aren't used.

 

[timwebb]

d3 is good. im looking for the short now.

 

[Perry Babin]

Pins 8 and 14 are likely shorted inside the IC.

Edit:
Sorry, that' should read, 7 and 14.

 

[timwebb]

i was looking for a data sheet on the ic but cant find one.

 

[mike49504]

http://www.irf.com/product-info/datasheets/data/ir2184.pdf

 

[timwebb]

what is pin 14 on this ic ?

 

[mike49504]

I put arrows pointing to pin 14 for both IC'S

 

[timwebb]

i was looking at the data sheet. there is nothing on pin 14.

 

[Perry Babin]

Maybe I should learn to count. I do OK up to 5 but after that, it's mainly luck if I get them in the right order.

It's 7 and 13.

 

[timwebb]

it was shorted. this is the one i need right?

IR21844SPBF for International Rectifier | Arrow Electronics Components

 

[Perry Babin]

That should be it. Confirm that the dimensions are correct. Some SMD ICs have different widths.