[tomheavybeats]

Hi, I have had the CP4500 working fine on my studio TAC 500 series rack but I recently bought it home, to use with my home setup Midas L10 rack and within a week the CP4500 has stopped working. The Meter light comes on but the In button no longer does anything (LED doesnt light up) and no compression happens. Before taking it apart to test I am wondering if anyone else has experienced issues with Midas rack? Maybe not enough power on the rails? My other 500 units work fine on it at the moment. I will obviously try it back in my studio rack but its going to be a while before i'm back there. Any help much appreciated!

[JPK]

It doesn't sound like a lack of power.
Maybe a earthing issue that injected some mains voltage leak into the chassis.
Check the V+, V- voltages.
Remove the input/output interface IC's U1, U7, U11, U17 and check again.
Check the LED D3 with your DMM.
What is your PCB revision number?

[tomheavybeats]

Thanks JPK, will try these next week when back with testing equipment. I removed the 4 IC's you mention and plugged in rack but still same issue. Revision of PCB is 1.3

[JPK]

Check if you do not have a bad connection on the meter wire connector.

[tomheavybeats]

Hi 
I am finally able to look at this to see whats wrong. I am getting correct voltages on pcb V- and V+ test points. When I check LED D3 i just get a reading of 370mv. I think LED gone but would that stop the whole unit from working?

Weirdly I have an HRK module and just plugged in to my Midas L10 and now all 11 LEDs on its meter have gone but unit is working. Is Midas killing my LEDs!?

[tomheavybeats]

Well I bought more LEDs so will see if that fixes but if you could point to more things I could test please?

[tomheavybeats]

Changed LED and all working! 

I have an issue with another CP4500 actually that I built for a friend. It has been working for over 2 years but now when the "in" push button is in the out position, it cuts audio altogether. Working fine when in.
I have yet to get it from him to repair but what should I look out for please?

[tomheavybeats]

Hello? Support? If not here where do we go for support?

[JPK]

Changed LED and all working!
Good!
Are you sure there is no overvoltage happening in the Midas, maybe temporarily at power up?

now when the "in" push button is in the out position, it cuts audio altogether.
This is the bypass mode.
On both channels?
Is this also a REV1.3 PCB?

[tomheavybeats]

Changed LED and all working!
Good!
Are you sure there is no overvoltage happening in the Midas, maybe temporarily at power up?

now when the "in" push button is in the out position, it cuts audio altogether.
This is the bypass mode.
On both channels?
Is this also a REV1.3 PCB?

Yes when in bypass, all audio on both channels cuts out. I will get PCB Rev number but it is the newer SMD version

[JPK]

It can only be in the bypass relays.
But both relays failing at the same time is very weird, unless something bad has been done like sending some voltage to the outputs?