Another sick CA-2010

C

Cadillac Kid

Addicted Member
I have a CA-2010 that has a problem. Right channel is dead with an intermittent loud pop(think gun shot). Then it goes into protection.

I have cleaned the coupler switch
Checked DC offset
Cleaned all other controls.

Injecting a signal into the main amp section while the preamp is switched out does not affect the problem. So I think I can focus on the main amp as the source.
I have the circuit diagram and a pretty good basic test bench.

Any suggestions on the next step for tracking to the issue? I would love to get this beautiful amp working.

Thanks for any assistance.
 
Cadillac Kid said:
I have a CA-2010 that has a problem. Right channel is dead with an intermittent loud pop(think gun shot). Then it goes into protection.

I have cleaned the coupler switch
Checked DC offset
Cleaned all other controls.

Injecting a signal into the main amp section while the preamp is switched out does not affect the problem. So I think I can focus on the main amp as the source.
I have the circuit diagram and a pretty good basic test bench.

Any suggestions on the next step for tracking to the issue? I would love to get this beautiful amp working.

Thanks for any assistance.
Click to expand...
Hook up a test speaker
tap on the driver board - looking for cold solder connections. If no luck. Pops are usually bad transistors talking to you.Have you tried to check the bias(idle current).. in "normal" class AB mode.
 
Fuses all check OK

Results from Idle Current Test TP1 and TP2

Normal Mode: -31 mV (should be +25mV)
Class A mode: -293 mV (should be +300mV)

I checked the TP polarity twice.


Next step, please...
 
Last edited:
Protect relay may have fouled contacts.Protect relay is on the underside of the 2010.

Still sounds like a bad solder connection or flaky transistor.
 
Last edited:
Can the contacts be reconditioned?
Why the reversed polarity of my TP readings?

I know it is not good practice, but I tested it while hot switching from Class A to Normal. There is no difference in sound, but the unit seems to be momentarily sucking current when switched judging by the room light dimming for a fraction of a second

Thank you so much for helping me with this.
 
I know it is not good practice, but I tested it while hot switching from Class A to Normal
Click to expand...
Good way to pit & carbon up the other relays contacts.
 
I don't hear the mode relay click when switching. The switch cover is missing, I wonder if this was intentional due to a problem.

Can I do a closer visual inspection of the relay by removing the cover?
 
Cadillac Kid said:
I don't hear the mode relay click when switching. The switch cover is missing, I wonder if this was intentional due to a problem.

Can I do a closer visual inspection of the relay by removing the cover?
Click to expand...

The mode relay is visible from the top. Yes ,you can pry off the plastic covers for a look see.

BTW both the mode relay and protect relay are the same part number. HL2-P-DC12V
 
Is there supposed to be a relay click when going to or from class A?
you've got me worried about the one I'm sending the fez... I don't recall hearing a click. I only switched it while powered on once or twice though, with the volume turned all the way down. and everything else seemed to work well, and it sounded awesome.


Sent from my GT-I9100 using Tapatalk 2
 
4seatPilot said:
Is there supposed to be a relay click when going to or from class A?
you've got me worried about the one I'm sending the fez... I don't recall hearing a click. I only switched it while powered on once or twice though, with the volume turned all the way down. and everything else seemed to work well, and it sounded awesome.


Sent from my GT-I9100 using Tapatalk 2
Click to expand...

Should be a "click" but you may not hear it over the mechanical click of the mode switch.
 
avionic said:
Should be a "click" but you may not hear it over the mechanical click of the mode switch.
Click to expand...

Ah... Good to know. It was definitely in class A if the heat produced is any indication!
Thanks... End of hijack. :)

Sent from my GT-I9100 using Tapatalk 2
 
4seatPilot said:
Thanks... End of hijack. :)
Click to expand...

Not a hijack, I was wondering the same thing. I assumed it should kick in when changing mode but was not sure.

My mode relay does nothing when switching. I noticed last night that the protection relay is arcing pretty good when it closes.
 
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