One of our amplifiers, Crown CT 8200, is not powering up (do not have power), and one has power, but red clipping LEDs are lit after powering up. Any idea how to troubleshoot? Thank you.

 

Are the outputs at a high DC level? If not, it probably has output relays, and the output before the relays are at a high DC level.
Has it blown one or other of the DC fuses?
If so it probably has a short-circuit output transistor or two.
With any luck, the damage has gone no further, and it will return to life after replacing the faulty ones.

 

Are the outputs at a high DC level? If not, it probably has output relays, and the output before the relays are at a high DC level.
Has it blown one or other of the DC fuses?
If so it probably has a short-circuit output transistor or two.
With any luck, the damage has gone no further, and it will return to life after replacing the faulty ones.

Thank you for your reply. I don"t know where the DC fuses are located to check it as well as the teansistors to check in power supply.. I will download the diagram Sir

 

Thank you for your reply. I don"t know where the DC fuses are located to check it as well as the teansistors to check in power supply.. I will download the diagram Sir

Probably pcb mounted. Does it have a 50/60Hz transformer or a switched-mode? I’m assuming 50/60Hz. Look where the secondary wires connect to the pcb. You should see the bridge rectifier and smoothing capacitors. Look around that area for the rail fuses.

 

Probably pcb mounted. Does it have a 50/60Hz transformer or a switched-mode? I’m assuming 50/60Hz. Look where the secondary wires connect to the pcb. You should see the bridge rectifier and smoothing capacitors. Look around that area for the rail fuses.

Thank you Sir. I will keep you posted as soon as I check the diagram or the main board itsef

 

Hello,

I can found an user manual.
Pages 17 and 18 show some troubleshooting.
I also found the schematics.
The powersection looks like an SMPS, see page 5 of the schematics.

Bertus

 

Hello,

I can found an user manual.
Pages 17 and 18 show some troubleshooting.
I also found the schematics.
The powersection looks like an SMPS, see page 5 of the schematics.

Bertus

Looks like a fixed frequency LLC resonant circuit to me. I like the way they combined the power supply for the drive to the top FET with the gate drive signal using a pulse transformer. Neat!
It’s a rail-switching amplifier Class G or Class H. It’s still a fair bet there’s a dead output transistor somewhere. Just hope for no collateral damage.

 

Hello,

I can found an user manual.
Pages 17 and 18 show some troubleshooting.
I also found the schematics.
The powersection looks like an SMPS, see page 5 of the schematics.

Bertus

Thank you so much Sir