2 amps with issues......gonna be fun

[toobnoob]

picked up two non working amps today.

first up is a kenwood kac-941. this one has issues with cracked traces on one of the circuit boards due to attempted theft by use of a crow bar. was able to find specs, but year of mfr no.

anyone know what year it is from?

second is a fosgate 360a2 and this amp was primarily the reason i got the two. this one has a supply issue. q10, which is one of fets feeding the primary of the power transformer looks like it went supernova. going to be an interesting unit to repair.

and finally, a note to perry babin, nice site you have there.

i am an e.t. by trade and find enjoyment working on this stuff in my spare time also.

[tsmith1315]

Originally Posted by toobnoob

picked up two non working amps today.

first up is a kenwood kac-941. this one has issues with cracked traces on one of the circuit boards due to attempted theft by use of a crow bar. was able to find specs, but year of mfr no.

anyone know what year it is from?

1990, produced for about 3 years.

A scan from their "10th annivesary" sales brochure:

(Higher resolution image available if you'd like)

[toobnoob]

awesome! thanks for posting that.

it's a nice looking amp. wonder if it reproduces as nice as it looks.

[Perry Babin]

If Q10 has failed, you MUST replace Q10, Q6, Q7 and Q11. Check the gate resistors on those FETs as well as Q1 and Q2.

After replacing the FETs, connect the ground and remote (no B+) and confirm that you have a clean square wave on the gate leg of each power supply FET (assuming that you have a scope).

For replacement of the FETs on the MEHSA strips:
http://www.diyaudio.com/forums/showt...81#post1901581

[toobnoob]

hey perry,

thanks for the info!

i do have a scope as a matter of fact, a tek type 422, which is definitely the best 50 bucks i have ever spent on a piece of test gear.

will post updates.

[tsmith1315]

Originally Posted by toobnoob

awesome! thanks for posting that.

it's a nice looking amp. wonder if it reproduces as nice as it looks.

It will sound very nice if you don't try to wring too much power out of it. Keep in mind it's not a high current amp, use efficient speakers and you'll be happy with performance.

When mounting, mind the heatsink holes. Drill bit or screwgun bits will have to pass through the upper holes to reach the mounting holes in the bottom part of the sink. It's very easy to scar up the those visible top holes with the chuck or drill bit when doing so...