Orion Cobalt 1-ch Class D amp goes in protect mode

[cam909ron]

i have a 1 channel orion cobalt amp CB3500.1D . when i run power to it it goes straight to protect mode .i opened it up and nothing looks blown so what do i check first the mosfets they are IRF640N ANY SUGGESTIONS WOULD BE GREATLY APP

 

[nigelwright7557]

My experience of class d faults are usually the mosfets blowing and often taking out the class d IC as well.

 

[cam909ron]

ic ??

 

[chermann]

ic ??

yep... the IC which generate the PWM "working" fequency - e.g. PWM 400kHz
try to get a schematic, internet to get more infos.... or look at the board

 

[cam909ron]

Can u show me what this looks like

 

[chermann]

Can u show me what this looks like

e.g. IRS2092 (irs2092 are mono class D amps) its a 16 pin device

 

[Rick PA Stadel]

Hi cam909ron,

Couple o' things --

- are you sure the 12V power supply can deliver enough current?

- I don't see a protection relay -- what do the speaker terminals measure during 'protect'?

- with that many big MOSFETs to drive (an IRF640 is rated 200V, 18A), the class-D IC might be somewhat protected (from catastrophic output device failure) by a layer of drivers

- depending on what 'Protect' is protecting the unit from, supplying power without the heatsinks may risk further damage -- OverVoltage, OverCurrent, UnderVoltage, dead rail, DC offset -- lotsa possibilities that are hard to assess without a manual, or at least a schematic

- what can you tell us about the history of the unit, esp what was going on when it died?

- it might get more attention (read 'useful responses') if you asked a moderator to move it to the Car Audio forum

- could you post a somewhat smaller, better focused picture?

Regards,
Rick

 

[Perry Babin]

This looks like a common class D audio circuit with a reconfigured driver board. It looks similar to this design:
Sonido Mask 2000.1

Do you have any experience repairing amplifiers?