Kicker KX600.4 protects and led alternately flashing

[nonprof]

Hello!

This amp looks weird...it alternately flashing the red and green light or steady red light. I don't have a defective output and power transistors. I've checked every supply but no problem.

But if I unbias the transistor that driving the Kicker logo lights (4 leds in parallel) this amp is powered up. Removing the gate diode or shorting the zener diode across LED connector this amp will works fine.

Any advice?

Please see attached picture.

Thank you!

[Perry Babin]

The LEDs appear to be grounded to the audio ground (RCA shields). Is that correct?

Does the amp go into protect mode when a source unit with a proper grounded RCA shield is connected?

[PapaZBill]

The LED leads are most likely shorting to the amp cover. Use diode checker or ohm meter to check continuity to bare metal on cover to LED leads and resistor. This of course should test open. If shorted, remove name badge and trim leads.

[nonprof]

RCA shield is that the ground of an RCA input? or the circular metal frame from RCA female connector?

I checked the continuity of the RCA shield and the AGND. no connection.

I powered the amp with my mobile phone use as a source unit but goes into protect ON and OFF (flashing lights alternately), rail voltages ups and down...

I removed LED strips from the metal cover but still ON and OFF.

But if you remove the supply or disconnect the base of the LED driver transistor. The ON and OFF gone and amp works perfect.

[Perry Babin]

I don't have the complete diagram so I'll leave the rest of the troubleshooting to PapaZBill since he's helping you.

[nonprof]

Thank you Perry and Papa!

I've found the problem...it was the adhesive from the Leds terminal that caused leakage to adjacent component. thanks!

[Perry Babin]

Are you referring to the brown fixative that's around the connector below? If so, any time you see that fixative and it's started to turn dark, you need to remove it. It becomes both conductive and corrosive. It will eat through the legs of components and through the conductive elements of resistors (causing them to open or change value).

[nonprof]

Originally Posted by Perry Babin

Are you referring to the brown fixative that's around the connector below? If so, any time you see that fixative and it's started to turn dark, you need to remove it. It becomes both conductive and corrosive. It will eat through the legs of components and through the conductive elements of resistors (causing them to open or change value).

Yes. You are right. Thank you again...

[PapaZBill]

Good catch! I have seen this a couple of times.Sometimes the problem is staring you right in the face, and finding it lacks looking in the right direction!

[Perry Babin]

PapaZBill, do you know what that fixative is? If you don't, could you research it and post the exact name? I know it's asking a bit much but I've never been able to find exactly what it is.