Cherry class D amplifier by Digital Amplifier Company looking to repair

[Hcg76]

I have a 5-CHerry amplifier made by the Digital Amplifier Company that no longer powers up. The owner of the company Tommy O’Brien unfortunately passed away several years ago so I’m looking for someone who may know how to service one of these class D amplifiers.

I’ve attached a few pictures to give an idea on the interior components with the cover off. Any help with someone who knows how to fix this kind of amp would be greatly appreciated.

 

[Doodski]

I can't say that I am a class D amplfier service and repair expert. I can though easily say that I have a huge humongous amount of experience in switching power supplies and surface mount PCB diagnosis and repairs. This amp is not a terrible horrible absurd issue but it's enough of an issue in that apparently there is no technical service literature and it is a surface mount design PCB and therefore parts identification and parts availability will for sure be questionable. I would not even accept the unit for diagnosis never mind repair. By accepting the unit for repair I would simply be wasting yours and my time and wasting your money and taking your estimate fee when I already know the outcome to a high degree of predictability. I hate stating stuff like I use a crystal ball, taro cards, chicken livers or even a Oiija Board to see the future but in this case I think the matter can be predicted to a reasonable conclusion.

 

[sceptical1]

You could check/replace the fuse for starters.

 

[Hcg76]

I appreciate the help.

 

[wwenze]

Rather than a single amplifier this looks more like 5 amplifiers plus a power supply unit.

Switched-mode power supplies are not known to live forever. Although you should be able to fine generic guide videos on how to fix one. You can also simply replace the power supply entirely and replace with a Meanwell or similar. An external brick also works if you don't want to fumble with hardware DIY.

 

[voodooless]

Maybe you can identify the make and model of the SMPS and find a replacement? Does it list the output voltage anywhere? Maybe a guesstimate can be made based on specs. Another SMPS can probably be found to replace it.

Found some sources that say 60V 1kW.

 

[voodooless]

The SMPS looks like an earlier incarnation of this one:

SMPS800RS | Connex Electronic

connexelectronic.com

Or this one:

SMPS800RE | Connex Electronic

connexelectronic.com

Peak is close to 1kW, so maybe it’s just one of those. Probably drop-in replacement.

 

[BeeKay]

Maybe that cap does not look too good?

 

[Hcg76]

Awesome advice from you guys. Can’t thank you enough.

 

[wwenze]

I've seen power supplies that still work with the capacitor in an even worse state, especially if the load is small compared to the max capability of the PSU. So I wouldn't put my eggs into the basket. But it's an easy check.

EDIT: Then again, everything is an easy check to the repairman. Rectifier open/short test, switching transistors short test and output short test, transformer open/short test can be done before taking out the soldering iron. Same for finding and checking ceramic capacitors for shorts, as are resistors to some extent.

 

[wwenze]

The SMPS looks like an earlier incarnation of this one:

SMPS800RS | Connex Electronic

connexelectronic.com

Or this one:

SMPS800RE | Connex Electronic

connexelectronic.com

Peak is close to 1kW, so maybe it’s just one of those. Probably drop-in replacement.

RS is single while RE is +- output. I see only 2 wires out in OP's photo, so it's RS

 

[snapsc]

This link may help…

Cherry Amp Repairs?

Cherry Amp Repairs?

www.audiocircle.com

 

[Hcg76]

RS is single while RE is +- output. I see only 2 wires out in OP's photo, so it's RS

Is this something that can be purchased off the shelf? Would think I can buy it and then simply have a local repair company swap the part?

 

[Hcg76]

This link may help…

Cherry Amp Repairs?

Cherry Amp Repairs?

www.audiocircle.com

Thank you. I just saw this link.

 

[Zinda]

I

You could check/replace the fuse for starters.

Made that mistake with an 8 channel lab gruppen amp that powered up with 2 channels flagged as problems. Replaced those 2 fuses and the amp died upon the next start up. The original damage may have been easily repaired, but the new damage burnt out the entire protection circuit, ironic hmmm.