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so I gave it a dash of contact spray (it smells good, if nothing else) and a good session of the ol' in-out thing.
And I always thought I was the only weird one liking that smell! 😁 PRF 7-78? Just having a plenty of that smell here (was about to send my Beomaster 5000 tuner to service as it was humming loudly, now I tried again and it's working perfectly! Had to give the switches a great deal of cleaning, though).
Good luck with the IR-thingy!
And I always thought I was the only weird one liking that smell! 😁 PRF 7-78?
Exactly! 😁😁😁
I don't use it if there's any better way, but now it did the trick.
Nice thread and great work, Mika! Hope the listening goes well!
Another day and time to continue. I finally realized how the IR receiver should be tuned - disconnect the front panel entirely, power it up from an external 5V supply and reprogram my home made "STB controller" to continuously send the B&O "volume down" command. Two hands are now quite enough and I managed the adjustment. Oddly, the most sensitive setting is completely to one side of the coil so I'm not sure if either the coil or the cap inside the coil tank are somehow a little bit off value now.
I believe tweaking the coil would've been unnecessary from the start - the adjustment is far from sensitive.
I also added one 4.7µ tantalum supply bypass cap for the IR preamp in case it would benefit something. Not much else I can do to the front panel, so after checking the cables I assemble it.
I also soldered a couple of lead wires to the detector part of the IR receiver, which is on the end of the CPU module, so that I can scope the signal at one intermediate point and the final logic level signal that goes to the CPU, even while the CPU module is installed. At the same time, I resoldered that area completely to make sure it doesn't have cracks - it unavoidably got bent back and forth when working with that tight IR connector.
After firing up the Beomaster again, I immediately note a lot of traffic on the IR signal going to the CPU. It's at clean logic levels, but those pulses are obviously originally just random noise. I've never had to look at this signal before, so I'm not sure if it should be like that - I suspect no. The real commands get through anyway with decent sensitivity, so I decide to once again try the Beomaster at the normal location.
Surprisingly, it works well over there; perhaps not perfect, but at least as good as before I started. The MCP works very well in its old place, so does the BL7000 which is located essentially behind the back of the Beomaster. I'll just let it be like this now, I'm getting bored with this step and the functioning is now completely acceptable.
***
In summary:
...tomorrow it's time to dig up some CDs from the stacked up boxes where I still have them 😁
***
Edit: Hah, something funny going on. If I connect the antenna cable (fed from the central antenna of the building), IR reception goes down the drain again. Restored once I disconnect the cable.
Could probably fix that with a galvanic isolator, but I think I'll just use a room antenna. The FM signal from the central antenna is crap anyway.
Another day and time to continue. I finally realized how the IR receiver should be tuned - disconnect the front panel entirely, power it up from an external 5V supply and reprogram my home made "STB controller" to continuously send the B&O "volume down" command. Two hands are now quite enough and I managed the adjustment. Oddly, the most sensitive setting is completely to one side of the coil so I'm not sure if either the coil or the cap inside the coil tank are somehow a little bit off value now.
I believe tweaking the coil would've been unnecessary from the start - the adjustment is far from sensitive.
I also added one 4.7µ tantalum supply bypass cap for the IR preamp in case it would benefit something. Not much else I can do to the front panel, so after checking the cables I assemble it.
I also soldered a couple of lead wires to the detector part of the IR receiver, which is on the end of the CPU module, so that I can scope the signal at one intermediate point and the final logic level signal that goes to the CPU, even while the CPU module is installed. At the same time, I resoldered that area completely to make sure it doesn't have cracks - it unavoidably got bent back and forth when working with that tight IR connector.
After firing up the Beomaster again, I immediately note a lot of traffic on the IR signal going to the CPU. It's at clean logic levels, but those pulses are obviously originally just random .........
I have no idea what you have said above but still mightily impressed.
I have no idea what you have said above but still mightily impressed.
Impressed too, but what has the central antenna to do with the remote ??
Location: Mexico city
Bad ground insulation from the aerial amp phantom PSU? A common problem.
Bad ground insulation from the aerial amp phantom PSU? A common problem.
Close... the thing is that in the same corner, I have an ugly PC that takes care of my TV recordings. A typical computer power supply has two mains suppressor caps connected from each mains line to the protective earth. When they are connected to a non-earthed mains socket (such as I have, this is a 40+ years old building with original electrics), the chassis of the computer ends up floating at around half the mains voltage. The available current is so small that it isn't dangerous, but will pinch your fingers when attaching cables.
Now the PC is connected to the TV socket of the same antenna outlet, and from there the 50 Hz disturbance got to the Beomaster. If I didn't have it there, some neighbour's kit probably would've ensured the antenna ground isn't clean. I'm not sure why it wasn't a problem before (all the ground straps etc are still attached)... the FM antenna signal from the rear panel socket goes to a cable that terminates in a small plug on the tuner board. For some reason, the sleeve of the plug was oxidized black and I cleaned it. Perhaps it just didn't have any ground connection left before this? But the fundamental problem is still somewhere else in the Beomaster. Now that the sun shines on the front panel, it's no good again.
Time to dig up some records. I believe it sounds a tiny bit better than before - more punchy and effortless in the top register, in particular. Was it worth it? Impossible to say. The last time I really paid attention to the sound was in my previous flat, a completely different room and completely different speakers.
I would've expected the bad coupling caps in the power amp inputs to make the most difference, but now I realize that since I have currently Beolab 8000s in the Powerlink outputs, they aren't even used. Wish I had my Pentavoxes up here...
Hi all,
I have recently bought a beomaster 6500. It seemed alright but after an hour or so I can hear a relay click, it switches of and on again resets the volume to default and resumes playing. If I disconnect it from power overnight it will play again for another hour or so.
Any idea's where to start looking ?
kind regards pim
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