Altec/Lansing 641 Subwoofer

[tech2014]

Had a humming sound, I found 8 blown ICs. The numbers on them say H21AF and P21AL. I can't find these parts anywhere, and a schematic or service manual would be helpful. Does anyone know where to get these parts?

PS-I found a shorted diode which is the reason for the parts blowing.

[budm]

Re: Altec/Lansing 641 Subwoofer

H21A is Optointerupter.
http://doc.chipfind.ru/fairchild/h21a.htm
Can we see good clear pictures to verify?

[tech2014]

Re: Altec/Lansing 641 Subwoofer

H21A is Optointerupter.
http://doc.chipfind.ru/fairchild/h21a.htm
Can we see good clear pictures to verify?

Here you go , hope the pic is ok. the part is different from what I have.

[budm]

Re: Altec/Lansing 641 Subwoofer

I cannot read the printing, really out of focus.
I can tell it is made by Fairchild Semiconductor, FDS????
Tell me what is printed on top there.

[tech2014]

Re: Altec/Lansing 641 Subwoofer

H21AF
FDS
6609A

The other part is
P21AL
FDS
6612A

[budm]

Re: Altec/Lansing 641 Subwoofer

Power MOSFETs
FDS6609, FDS6612

You said they are blown, how did you find that out without knowing what they are and without the pin out?
Check the resistance between S and D pins, make sure to post the readings if they are in OHMS, K Ohms, or M Ohms.

[tech2014]

Re: Altec/Lansing 641 Subwoofer

Because they were burnt/charred. 5 of them were burnt so I would rather be safe and replace all. Here is a pic.

[tech2014]

Re: Altec/Lansing 641 Subwoofer

Ok I found FDS6612A at digikey but the FDS6609A is obsolete. Digikey found a replacement part for it so all is good. Thanks for the help budm.

[budm]

Re: Altec/Lansing 641 Subwoofer

OK, that is Class D amplifier, The LX1711 IC should be check otherwise it may blow up the MOSFETs.
http://www.microsemi.com/document-po...11-100evug-pdf

http://www.microsemi.com/existing-parts/parts/56877 It is obsoleted part.

[tech2014]

Re: Altec/Lansing 641 Subwoofer

ok I will check it. BTW, is there a schematic for the board or a service manual, so I can check and make sure there are no other bad components. I don't want to install the new parts, power up and get a smoke show.

[tech2014]

Re: Altec/Lansing 641 Subwoofer

does anyone know where I can get LX1711 IC. One of the LX1711 IC reads 0 ohms on pin 23.

[budm]

Re: Altec/Lansing 641 Subwoofer

Try EBAY?
http://www.ebay.com/itm/1PCS-LX1711C...item58b1068743