pg octane 900.5 repair

Read the second paragraph before you take the amp apart to check for bridged solder joints on the bottom of the board.

We seem to still have a problem at the output transistors.  Check and make sure you do not have a bridged solder joint on one of the outputs you replaced.  Check the top and the bottom of the board.  Also check to see that you did put them back in the right spot.  In order to check this, the middle leg of one of the rectifier diodes will show a dead short between the middle or the right leg of the outputs.  The CA diode will be connected to one and the CC will be connected to the other.  You may have to pull the clamps off of the 4 channel part and verify which output is connected to which diode.  They will be the same on the part of the amp we are working on. 

Before you do anything else,  run the amp for a few minutes to see if the heat sink is heating up on the supply you worked on.  Make sure you mount it back into the sink.  If there is a problem with the drivers, the 44s will heat up on that side before they heat up on the other side.  After you leave it on for a bit and determine that it is not heating up, check for shorted solder joints on the outputs.  Also check the resistance of the rectangular concrete looking resistors near the outputs.  Now set your meter to the diode test function and check for shorted driver transistors near the outputs you changed.  Check all possible combinations of those legs.  If you get any readings below .300, check the same transistor on one of the other channels of the amp.

After you test for heat with the diodes still removed, at least remove the 36s, they may be leaking, Since you have them I would replace them.  They are rated at the same current as the 35s, they went through the same abuse as the 35s, they may have survived but could be weak. 

We are getting close.  But just to be safe, power it back up and leave it on for about 5 minutes.  You need to monitor the heat sink the entire time to see if it is getting warm.  No Speaker wires and no RCA jacks.  After 5 mnutes you should begin to feel it warming slightly.  If it is getting hot you may want to stop.  If it is only getting a few degrees above ambient, connect speaker wires and RCA cables and try playing it.  With the 5 amp fuses, it will only play at a very low volume, turn it up until you can barely hear any audio.  Walk areound the vehicle listening carefully to each speaker.  If they all sound free of distortion,  gradually turn the volume up until you blow the fuses.  If all sounded good until the fuse blew, Cross your fingers and insert the proper size fuses.  Play it again and see what happens.