Autotek MX5000 Repair


Autotek Mean Machine MX5000 Amplifier



This amp came from the Internet, it's a pretty good amp, basically same thing (same exact output section) as the MX3000.1, which is also a good amp. The difference is this amp uses larger FETs on the power supply. This amp is a 2 Channel Class D, kind of unusual, can be "bridged" to drive a 2 ohm load with lots of power.



Click image to Enlarge the image



The Autotek Mean Machine line of Amplifiers is a good line I think.

500 watts x 2 channels @ 4 ohms. Pretty good for 4 ohm load, goes up alot
if you drop down to 1 ohm per channel or strap it at 2 ohms (bridged)

Nice looking amp on the inside.

This is a problem with these amps (yes aren't there always problems) they
use modules to make the outputs work in this amp, and they are proprietary
modules with defaced ICs (DL101 and DL102 aren't real IC numbers). The ICs
cannot be identified because of this. These modules are made by Dlogix
and they will not sell you less than 500 units. Luckily, these modules
(or at least the 2 defaced IC's) seem to rarely fail, so most times it
is not a concern. ***UPDATE We no longer service the older Class D amplifiers like this one. The modules do fail, eventually, and render the amp useless, sad because they were a nicely built amplifier. The newer Class D amps do not use proprietary output drive modules like these older amps and are 100% serviceable.

Each channel requires a module, since this amp is 2 channel there are 2
modules.

These power supply FETs, IRFP064N are pretty heavy duty (100 amps each max
rating) but somehow they went up in smoke anyway. There are 2 power
supplies in this amp, each has 6 IRFP064N (groups of 3). 12 Total.

Closeup of power supply driver boards. These rarely have problems.

The power supply FET drivers. These always have problems and have been
replaced here.

Closeup of output FETs (one side). These are P Channel FETs. This amp
uses P Channel and N Channel FETs, 5 each P channel and 4 each N channel.
P Channel FETs are normally not rated for as much current as equivalent
N Channel FETs so they use more P channels to make up for the difference.

All clamp bars removed, about to pull the mainboard from the amp, this is
a pretty good size amp.

While not a 5000 watt amp, this amp is capable of close to 3000 watts. It
has the same output section(s) as the MX3000.1, don't let anyone tell you
they are different. The differences are in the power supply, this amp uses
larger FETs and less of them, where the MX3000.1 uses more smaller FETs.
MX3000.1 = 16 RFP70n06 (70 amp FETs)
MX5000 = 12 IRFP064N (100 amp FETs)
Output Sections are identical.

Mainboard removed from the heatsink.

The reason the power supply failed is likely because some of the output FETs
failed. They are on the channel in the mid section of the board, they have
been removed in this pic (the bad FETs have been removed).

Now onto the smokey power supply, remove all the bad FETs.

Nice clean removal of those FETs.

All gone, ready for new ones.

All bad parts now removed from the mainboard.

New power supply FETs magically appear. All the outputs on the bad channel
will be replaced. This is the proper way to do things when repairing an
amp.

Now new output FETs magically appear.

Board is placed back into heatsink.

All clamped down and load testing! Done.



This repair was easy, kinda expensive parts, but easy because nothing weird was wrong with the amp once the new parts were installed. Lots of times the amp still won't work correctly when new parts are installed and that's when you give up if you are a shadetree amp tech, no scope, no find the problem. This one had no problems. Good as New!