Kenwood subwoofer amp dead with fuse blown

[jasonbay13]

I have a kenwood sw-38ht that has stopped working with a blown fuse. i tried another fuse and with no input or output connected it blew instantly when i turned it on.

i looked the components over and do not see any damaged electronics. i checked resistance between positive and negative coming out of the bridge rectifier and it shows .2ohm. i have desoldered the bridge rectifier to be sure it was not shorted.

do you think it is the TDA7293V that has gone bad? would it be worth replacing, it is a fairly old amp.

attached is service manual, can pull the camera out if you want pics.

[stj]

Re: Kenwood subwoofer amp dead with fuse blown

maybe - desolder that chip and meter it again.
as to if it's worth it - it depends on the cost of the chip - but probably it's well worth it.

[jasonbay13]

Re: Kenwood subwoofer amp dead with fuse blown

i found it on ebay for like $4 including shipping. figure it would be worth a shot for that much. but the thnig is, i dont know what pins to check on that chip.

[stj]

Re: Kenwood subwoofer amp dead with fuse blown

just look at the diagram and meter between B+ and B-

or desolder it and see if the fuse still blows.

[jasonbay13]

Re: Kenwood subwoofer amp dead with fuse blown

definitely looks like its the ic. desoldered it and b+ and b- is now ~2megohms affected by the caps i think. the respective pins on the ic still .2ohm. ordered the new tda7293. will let you know how it works out.

[stj]

Re: Kenwood subwoofer amp dead with fuse blown

V or H on the end of the part number is important btw, it's the way the pins are bent.
(V for vertical mounting, H for horizontal)

[jasonbay13]

Re: Kenwood subwoofer amp dead with fuse blown

Soldered the new chip on, plugged it in and flipped the switch. and boom, sub is working again

thanks stj.