JBL EON 615 no audio output

[Michael27]

Hi

Currently I'm facing a weird issue on my Eon 615. The unit starts up, signal indicator is active but no sound comes out. I've replaced the entire input board assembly with a known working one the results did not change. I've replaced the Power amp/smps board and the unit gives sound. So I went back to the faulty board replaced the 2 TDA8954th Ics and theres still no audio.

Any help will be greatly appreciated..

[The Dude]

Have you checked the speakers? If the power amp failed and output DC voltage to the speakers, it's possible the speakers burned open.

[Michael27]

Speakers are fine. I've tried another power amp/ smps board(both are incorporated into 1 pcb)and sound passes thru. Theres something on that smps board that caused the amplifier circuit to mute

[The Dude]

Have you tried a factory reset? It could just be corrupt settings.

[Michael27]

Yes I have done a factory reset. I can confirm it is a powersupply fault as 1000uf 50v capacitors were swelled(I replaced them already)

[Jazz P Bass]

There are markings on the power board for the HV rails.
+35/ -35Vdc I think.
Are both voltages good?

Power Board PCB part #: Assembly JBL 5054674

[Michael27]

Yup. The voltages are there. For some reason the TDA8954TH is stuck on mute..usually on a working speaker you would hear a very low audible hiss with no input signal. In this case I'm not getting that. I do get a very very very low pop noise on switch on which is normal on these Eons. Other than that I'm still very confused.

[Michael27]

It's not the input pcb as I've tried a working one.

[Jazz P Bass]

The Mode pin has to be greater than 4.2Vdc for the amp output to operate.

Kind of hard to get at the ic but what voltage is on the pin?

TDA8954_Pinout.pdf

TDA8954_ Mute.pdf

[Michael27]

I cannot do any measurements now as the power supply is completely dead on the secondary stage. Could a power surge cause this type of failure. The initial fault was no sound output and now a new fault arises