Harman Kardon AVR260 amp, 2013

34 screws and numerous ribbon connectors to remove, to get the rear panel apart , just to see let alone test the fuse that seems to pass mains power to the big Tx , coming out of standby. Better check there is no power going to the big Tx first. There is little current surge at power on , so suggestive of no main Tx coming on, just the little standby Tx.

nothing to do with the current problem. Mighty strange place to put 2x fans, each one 20mm from a wall of unperforated aluminium, how the air is supposed to pass and cool the H/S vanes is beyond me.

No output from the headphone jack?

Does injecting audion to a direct-input (?6-ch direct input?) get you any output? This bypasses the preamps.

Ha.

Sounds like some stellar all-around design there.

no clicks or hiss there

I'll try that tomorrow as well as checking for mains on the big Tx and then a drive voltage over the D912 back emf preventer to the relay, which is about all that is observable without taking the amp apart. Amazing that there would seem to be 2 fuses buried at the rear , behind the relay, cannot even see any part of them. Perhaps some traces are probable to check those fuses without dismantling

I convinced myself that the low switch on surge was not for the main Tx and should have checked there first. Went down the farting about route. Removing a cable tie to move a filter toroid and rats nest of thick cables I could see one end of the elusive fuse. The primary side of the Tx is not probable except at that point and 2.1R to mains neutral, standby Tx

4.4K. Pushing a thin brazing rod through a hole in a rear pcb it was possible to make contact with the other end of that fuse and ok. Powering up and 5.9V over the 6V power relay and clickover. 2 lots of +/-44V dc off the main ps and 23,19,19,23 Vac on the minor secondaries. So next to check the minor DC rails and whether the preamp is working. Looking more like something silly like a child-proof lockout via some set of keypresses or something like that. But nothing like a key symbol appearing in the display.

I've just noticed on the schema an insertion sense contact on the ground of the phones socket, not found where that sensing goes , but will check that out first

The phones socket insert switch is operating correctly. Feeding signal in direct or selecting FM tuner , preset frequencies on the display but no audio out. The minor DC rails seem ok except the supplies to the +/-15V regulators. Schematic shows the raw voltages should be +/-17V in use, but measure

-25V and 23V and only 18 to 20mV dropped over the .47R fusible resistors in line . So looks as though little or no loading of those rails. About .2 amp stable draw from the mains and the main h/s is warm after

10 minutes or so

Removed the little tuner pcb to get some view room The Power_Mute line seems to come from p38 of 100 pin Toshiba T5CC1 IC. It is at 3.3V which seems to be for normal unmute. Next I'll try feeding a signal directly into the edgemost chanel SBR to confirm the amp would work if it was not killed by something in the way of firmware or software or somesuch.

Just as well archive.org still has an English language version of the user manual, as only German,Polish or Dutch seems to be available from the h-k sites now

22 nov 2010 version

I'd noticed this business , but thought it was normal, not familiar with htese sorts of beasts "Letters flash in the Channel Indicator Display (14) " then goes on to say "and Digital Audio stops Digital audio feed paused ? Resume play for DVD/Blu-ray "

So perhaps the last useage was DVD and stopped mid-play and the AVR260 is too clever to realise that if it is switched off at the mains then an owner is not interested in resuming play. As I don't have that DVD and disc of last useage a "factory reset " of 5 sec press of OK while in standby mode, is called for to delete this guff from memory

The reset works in the sense that legend RESET appears in display but the memory contents are not erased ie the tuner preset frequencies are still there