Memphis MOJO 16-MCD4KW

[mike49504]

I got 2 memphi mojo's in for repair. 1 amp has IRFP360's and the other one has IRFP360lc's.

Both amps have been fixed at 1 point .

Wondering if anyone knows what outputs are the correct ones for theese amps. IRFP360 or IRFP360lc ??

[m4ick]

Found this:

Missing OUT Fets Memphis 16-mcd2500

[mike49504]

Ok i found out that it takes the 360's not the 360LC'S.

My next question is are they any good cross parts for the A1023, C1027 drivers?

Or does anyone know where i can buy the A1023's and C1027's from?

[m4ick]

Most people aren't fond of ordering from Asia but Taydaelectronics.com was the ONLY place I have ever found KTC1027. I have gotten output mosfets from them that didn't work but never had a problem with their small signal transistors.

I have used a cross that had the EXACT same specs from mouser with a slightly lower power dissipation and they DID NOT work, the amp (orion 2500d) would protect a few moments after the speaker relay would engage. The parts from Tayda worked just fine.

[mike49504]

Does anyone know the correct value of theis resistor? And the wattage it looks like a 1/4 watt to me but i orderd resistors from digikey before that looked liked 1/4 watt and they swore up and down they were 1 watt.

The resistor measures 33 ohms out of the board just wondering if that correct?

[Perry Babin]

That's right. 33 ohms, 1w.

The size of the resistor depends, in part, on the materials that it's made of. Resistors can be smaller if the materials can withstand higher temperatures. When using miniature resistors, you may want to install them standing off of the board a bit. This will prevent damaging the board from the heat and will prevent the solder connections from oxidizing over time.

[mike49504]

Thanks Perry,

Next question is Im rebuilding the power supply in this amp right now.
Before i put any fets in i wanna look at the gate signal.

If no fets are in the amp will it still blow the outputs if theres a problem in the output section?

[Perry Babin]

I've never heard of that happening in any amp. I won't say it can't happen (since this amp has the small, low voltage/driver power supply) but I think it's highly unlikely.

[mike49504]

A 2k resistor belongs here. WOuld a 2.2k resistor work?

[Perry Babin]

It would probably work but it would be better if you used a lower value instead of a higher value. I'm assuming that this is to allow you to continue troubleshooting.