Definitive Technology SuperCube III Component Level Repair Troubleshooting Photos

[DumpsterFire]

Hi Everyone,

I'm attempting to troubleshoot my Definitive Technology Supercube III and proceed with component level repair if possible. I have not been able to find a DIY guide on this.

I've confirmed the amp receives power indicated by the Red LED light, however I have no sound/bass coming from the amp when I attempt to unplug and plug the RCA sub cable to the LFE input (the photo I took is testing other inputs). I have a secondary sub, which I tested to eliminate that it's an sub output receiver problem.

The board looks fairly clean except for ST tip32c and LM337LZ transistors that seems to have some brown residue around the yellow potting material (photos attached below). I have not tested the pins for voltage and wasn't sure if this would affect the LFE input for sound.

https://cdn.badcaps-static.com/pdfs/...4cb7a47e97.pdf

https://cdn.badcaps-static.com/pdfs/...4f0ad28f91.pdf

Does anyone have a schematic or way to possibly confirm the voltages on the transistor.

Thanks,

[budm]

Re: Definitive Technology SuperCube III Component Level Repair Troubleshooting Photos

You must remove those glues first, as you can see in the last picture, it is turning dark brown, these glues become corrosive and will eat away metal and also become conductive.
https://www.badcaps.net/forum/showthread.php?t=34692

[tobascovodka]

Re: Definitive Technology SuperCube III Component Level Repair Troubleshooting Photos

Hi DumpsterFire, I have the same issue as you do with my III, have you had any luck in testing?

With so many refurbished models it shouldn't be the adhesives, it is likely a component, I will be testing voltages tomorrow but I know my caps charged on both the amp and preamp.

[westernmetro]

Re: Definitive Technology SuperCube III Component Level Repair Troubleshooting Photos

I am also troubleshooting a supercube III.
There is a 5 wire plug from the crossover system to the amp.
I think the crossover is ok with a bad amp?

The signal plug has one wire is a different color and 4 wires same color.

I am thinking one (the different color) may be a common/circuit board ground and the other 4 two + and two - for low level speaker input leads for the amp.

The amp appears to have two parallel amp circuits.

Anyone with an electronic background who can suggest how to test leads to determine what they are?

I would like to input low level signal to test the amp separately.

Another different question-
Also- this system is a 120v system.
There appears to be a transformer coil dropping the voltage- probably to DC.
I would also like to identify a way to see if this could have the power supply hacked to run on 12v in a motorhome. I am can do guy but have no electicsal engineering info.
i just solder and replace things and hack them.

Thanks, Scott

[stj]

Re: Definitive Technology SuperCube III Component Level Repair Troubleshooting Photos

any decent sub will use more than 12v - usually about 30v

[srt1]

Re: Definitive Technology SuperCube III Component Level Repair Troubleshooting Photos

Any one have schematic of super cube 3 , mine have no power