Harman Kardon AVR 2600 Wierd DSP issue?

[ikonw8]

All,

I have a Harman Kardon AVR 2600. I thought that when I replaced three output transistors and two emitter resistors, I had solved the issues on this receiver. Not so fast.

When this unit is decoding PCM audio (from any source: COAX, HDMI, Optical) into Logic 7, DTS NEO, Dolby Digital - not issues. All seven channels (or 5) decode perfectly.

When it is in Dolby Pro Logic IIx - I get very noisy, digitally distorted sounding audio on the surround and centre channels. Only Pro Logic IIx.

Voltages on the DSP board are all perfect. I reflowed the DSP and associated ICs, RAM - no resolution.
The firmware was already at the latest version - but I re-flashed the firmware using the upgrade process anyway. No resolution.

Anyone run into anything like this?

 

[Binkman]

G'day;
Is this issue that important? So... keep your finger off the dolby. I don't think they ever got it right. (dolby ) the amps already user equalized or usually is. upgrading firmware is rare. but it worked for you. Don't even think AVS forum? is all that popular. but keep the finger off the dolby if it solves it.

 

[ikonw8]

Important? Lots more things are important.... But, I like it when the receiver works like it was intended too. Anyway, the receiver will auto select what it thinks is the best surround... the commercials at the beginning of a DVD could be encoded in 2 channel PCM; and the main movie in 5.1 or 7.1. Pretty nasty surprise when you get the distortion and are not expecting it. The distorted audio is much higher volume than the non-distorted channels.

 

[Binkman]

The distorted audio is much higher volume than the non-distorted channels.

turn the vol. down before the movie begins? there is no correction for intentional preempt movie ads to do what they want. I use a monitor and laptop hdmi cable setup..source audio from a small monitor.. but have hooked up av amp from the t.v. even rca cables work I can turn off the t.v. Yeah i've come across a couple cd screw ups as you describe it. So my t.v. also has the option limit sudden vol. surges I think with balanced on
(already edited couple times.
even if you had a fold-out orig. service manual for the majority of these brand av's x 35mb of on line manuals? nobody want's to mess with it.

 

[ikonw8]

Thanks for the reply Binkman. Going to pack this one up for now... and try to set it up so it never goes into Dolby PLIIx by itself.