Mode Four smokin' but with real smoke!

[booj]

Hooked it up to a 16 ohm load with a scope and meter to give it a power check. Got about 10 clean volts out on the meter, when it "dissassembled" itself.
I had previously looked it over and saw nothing amiss, and had checked it out at low level with a guitar and speaker. I put it back to gether and was just making sure it put out full power.
It started cutting out at a certain output level and go into protect mode. I just wanted to see what the actual voltage was that it cut out at (the last time was 10 volts)
Besides the output chips, which I feel like I ought to replace all four of, I suspect the protect circuit was doing its job until the last go around.
Anybody got any experience with this amp?
I'll replace the chips, but I sure don't want the same thing to happen.
mf350_60_02_iss3.pdf

mf350_61_02_iss3.pdf

mf350_62_02_iss2.pdf

pcbp-00121.pdf

[clydey]

steve connor put me right on that one (scope)
there is two threads just finished with all the info you will need
cheers

[Enzo]

The output of the MF350 is bridged, NEITHER side of the speaker is ground. If you connected a scope ground to the return side of the speaker, you just grounded out half the power amp, and that blows tham up. You can connect the scope to chassis and then view either side of the load, but NEVER connect a scope ground or any other ground to either side of the speaker.

The four modules are in bridge, but none are parallel, on each side, one module amplifies and its mate is a follower. When one blows, always replace all four.