The amp is fully functional. The DSP (audio processor) chip that is causing the no sound fault has been professionally replaced with a new and non-perishable one, so the equipment will last for many years. Repair cost 195 EUR. The warranty for this repair is 12 months.

Included:
replacement new RC-743M remote control (differs from source selection buttons - no PC and ZONE2. Can be switched on the front panel or on-screen menu).

The equipment is 100% functional. Nothing crackles on any channel. HDMI is running - version 1.4a, i.e. it has support for Dolby True HD and DTS-HD 3D image standards.
The enabled HDMI pass through function allows you to send video and audio with only "standby" enabled.

Advanced properties

• THX® Select2 Plus™ certified
• HDMI™ version 1.4a supporting 3D and Audio Return Channel as well as Deep Color™, x.v.Color™, LipSync, Dolby® TrueHD, DTS-HD Master Audio™, DVD-Audio, Super Audio CD, Multichannel PCM and CEC
• 7 HDMI inputs (1 front/6 rear), 1 output
• Audyssey DSX™ and Dolby® Pro Logic® IIz for new surround channels
• Jitter-Cleaning Circuit Technology
• Ability to play streaming audio files (MP3, WMA, WMA Lossless, FLAC, WAV, Ogg Vorbis, AAC, and LPCM) from the network
• Ability to connect Internet radio via Last.fm, Napster and vTuner applications
• Windows® 7 and DLNA Version 1.5 certified
• Firmware update via Ethernet and USB port
• Front USB input for flash drives, iPhone and iPod (allows display of album covers)
Amplifier properties

• 170 watts/ch output power into 6 ohms, 1 kHz, IEC, one channel driven
• Wide Range Amplifier Technology (WRAT)
• Push-pull parallel amplification concept with three-stage inverted Darlington circulation
• Massive High Current Power Supply (H.C.P.S. - High Current Power Supply)
• Linear arrangement of optimal amplification circuits

Processing properties

• Burr-Brown 192kHz/24-Bit DACs (PCM1690) for all channels
• Advanced 32-bit DSP Processing (DA830 & CS49834 Chips)
• Dolby® TrueHD, DTS-HD Master Audio™, Dolby® Digital Plus, DTS-HD High-Resolution Audio™ decoders
• HDMI video upscaling to 1080p with Faroudja DCDi Cinema™
• 4 DSP modes for games: Rock, Sports, Action and RPG (Role Playing Game)
• Music Optimizer™ for compressed music files
• Direct mode and Pure Audio mode
• A-Form mode
• Theater-Dimensional Virtual Surround mode - surround sound from two speakers
Connection properties
• Universal port for one-cable connection of Onkyo peripherals
• Component video connections (2 inputs and 1 output)
• 4 S-Video Inputs, 2 Outputs
• D-sub (15 pin) input for computer or analog RGB
• Front panel audio input for portable devices
• 5 digital inputs (2 optical and 3 coaxial)
• 5 A/V inputs (1 front, 4 rear), 1 output
• Colour-coded 7.1 speaker terminals
• Video Out (Monitor)
• 1 audio input
• Phono input
• Color-coded 7.2 pre-out speaker terminals
• Zone 2 active and Zone 2 Line-Out to another room (separate source)
• RS232, IR (Input) and 12V Trigger Out (Zone 2) connectivity possible
• Ability to make Bi-Amp connections
• Colour-coded speaker terminals accepting banana plugs
• Device control system using HDMI (Remote Interactive over HDMI - RIHD)
Other properties

• On Screen Display (OSD) via HDMI
• Audyssey Dynamic Volume™ maintains optimal listening levels and dynamic range
• Audyssey Dynamic EQ™ for volume correction
• 40/50/60/70/80/90/100/120/150/200 Hz crossover adjustment
• A/V sync adjustment function (up to 250ms in 5ms increments)
• Possibility to preset 40 FM/AM stations
• RDS (PS/RT/PTY/TP)
• Compatible with RI (Remote Interactive) iPod Dock

I am listing the equipment at a bargain price, because I got it for free from a neighbor and repaired it in a professional service. I would probably take it for myself, but I don't want to betray my Harman ;)