Anthem MRX500 - no sound. R2A15218FP issue??

[benspawn02]

Re: Anthem MRX500 - no sound. R2A15218FP issue??

btw I had a no sound problem with a Marantz SR7011. There are four DSP ic's on that board and each has it's own serial flash. The flash for DSP3 had become corrupted (partially erased) and I was able to rebuild it with the dumps from the other flashes. After reprogramming it the receiver worked fine and I still use it a few times a week in my movie room. It replaced an aging Newcastle R-972 because I wanted to try out Auro3d.

This sounds great but it's a bit beyond my scope. If you don't mind me asking a few questions to guide to see if I can even attempt this. . .
Did you have a particular rig that you had to build? Remove the DSP chip from the board? Anywhere you can point me in reading a how-to?

EDITED:
So after I posted the above, I did a quick Google.
Based on this. . . https://www.riverloopsecurity.com/bl...5/hw-101-jtag/
I found some info about JTAG and it appears that this TMS chip may have a JTAG. There's a ribbon cable connector (9 pin) roughly next to the TMS DSP chip. So I managed to figure out that the chips are daisy-chained where TDO of the first chip is routed into the TDI of the second.
I managed to trace the following on the "JTAG connector"
1 - Vcc IO, 2 - Gnd, 3 - TMC, 4 - EMU1, 5 - EMU0, 6 - TDO, 7 - TDI, 8 - TMS, 9 - TRST

So that's a first step, now I just need to know how to flash the chip. . .

[mmartell]

Re: Anthem MRX500 - no sound. R2A15218FP issue??

If you manage this read them both first and compare.

I've not done what you're attempting so no help there but do keep posting your progress.

[benspawn02]

Re: Anthem MRX500 - no sound. R2A15218FP issue??

If you manage this read them both first and compare.

I've not done what you're attempting so no help there but do keep posting your progress.

How did you manage to retrieve the dump from your marantz dsp flash and subsequently reprogram it?

[mmartell]

Re: Anthem MRX500 - no sound. R2A15218FP issue??

They were soic8's so I have the CH341 for that.

[benspawn02]

Re: Anthem MRX500 - no sound. R2A15218FP issue??

Ah right ok. No progress on my end so far. I ordered a JTAG interface and will see if I can get anything.

[benspawn02]

Re: Anthem MRX500 - no sound. R2A15218FP issue??

So a little bit of an update. I received my JTAG interface today and got everything wired up. While I was connecting to it, I kept getting an error. So I started probing around and noticed that my 3.3V source voltage was dipping down to 0.9V or so.

At first I thought maybe the chinese JTAG clone was not putting out enough power. So I wired up an external 3.3V, and same thing happened, the voltage dipped down to 1.2V or so. So it appears that something is "shorted" or drawing down power that the DSP chip is not getting enough voltage to turn on.

I'm back-tracing the circuitry trying to identify the broken component but no luck so far. Will update further.