Sub channel not working - Directed 1100d5

[CanadianDream]

Hey guys, I haven't used this amp in a while and was just hooking it up.

It is a 5 channel car audio amp, and the sub channel seems to have no output.

I have the feeling it is not receiving a RCA input signal (but could be blown I don't know). I have tried both using the internally summed input for the sub (comes from ch 1-2 which is working fine so the rca source is good), or when I directly connect into the sub input.

Now, car audio I am good with - repairing amps and troubleshooting I am at a loss.

The amplifier clearly has power (green light, and output on ch 1-2), a good +12V amp on signal and no protection lights.

I have tested the sub output with 3 different subs to make sure it is not a sub issue, or impedance issue.

Any help what to check from here would be amazing.

 

[Perry Babin]

I'm not familiar with the amp but if you post a few photos (or email them if they're high res), I'll try to help.

babin_perry@yahoo.com

 

[CanadianDream]

Thanks a lot for the reply. Do you want interior pics, or input pics.

Here is a website with the exterior pic.
http://www.drdetailshop.com/d1100D5.htm

Here is the manual (.pdf)
http://www.directed.com/guides/manuals/og/directed_audio/G1100d5.pdf

Anything more specific please ask.

Thanks.

 

[Perry Babin]

I need photos of the internals so I can see if I recognize the circuits they're using. The area around the power supply and the sub channel are most important.

 

[I Am An Idiot]

No X-Ray Vision Software? You used to have some.

 

[1moreamp]

It has a vertical riser driver card that is very similar to other directed and Memphis cookie cutter designed Class D amps. It uses IRF9640 and 640 outputs, and the driver board is the discrete totem pole type fet driver setup used in Crossfire, and many others. I have one of these sitting here in my things to do on a slow day pile.

If you have ever seen a Memphis 500 or a Crossfire 1000 well its the same driver card as used in those amps. And by same I mean exactly the same parts, card, design, and even PCB material. The directed has relay speaker protection also so that's why there is no bass, the sub channel has failed, most likely at the outputs but not limited to just that as the driver transistor get so hot they like to melt off the card as they fail....Hope this X-ray vision is of some use to my friends here .....

 

[CanadianDream]

Well a lot of that is over my head...but let me ask... is this testable? repairable?

I will look into getting interior shots tonight.

Thank you very much for the help.

 

[Perry Babin]

If it's like the memphis amps, it should be relatively simple to repair. Post the photos and we'll go from there.

 

[CanadianDream]

So good and bad news. I ended up pulling all the external fuses, and pulling the amp out of the car to take pictures. Bench tested it, and works fine. Strange part is I reinstalled the amp and working fine.

My concern is it is an intermittent fault now. Will just have to wait and see. It definitely had nothing to do with rca inputs, or loose connections as both the internal summed input, or using the external sub input failed.

Thanks for all the posts, and I will update this thread "when" the problem returns. Probably just about the time I have it all nicely installed again