Beocenter 7700 power supply problem

[Xavier]

It is difficult to buy a relay with such parameters. I have been in several local electronics stores and there is only the one I used before. I am looking for a suitable relay in the web now.

X

[Xavier]

Hi again.

Unfortunately, I can’t find the relay.
On eBay are similar to buy, but in the old relay the distance between coil pins and com pins is about 15 mm, and in those available it is 20 mm (I marked the difference in red color in the picture)

For example, OMRON: https://tiny.pl/wbrlh

And also FINDER: https://tiny.pl/wbrlq

Can anyone tell me where to find the relay?

—————-

In the meantime I did two tests.

First, I connected the beocenter to the power supply without a relay, but it didn’t respond. I thought it would work in standby mode and possibly just not respond to switching on.

I also checked if there is DC power on the paths leading to the coil. The measurement did not indicate a voltage.

How to understand it?

Xavier

[Mark-sf]

Check the link in my first reply to you for the relay.

[Xavier]

Thanks, I completely forgot about it. I will order this relay and a few small things by the way. But what about power? Shouldn’t beocenter work in standby mode without a relay?

[Xavier]

Hi again.

I picked up the relay from the beoparts website and put it on.

Now, after I plug it in, the relay disconnects, so it works. But the display appears for a split second “P1” and something that I can’t read ( short video below), and Beo turns off completely. Not for standby mode.

Any suggestions?

X

[Xavier]

Hello!

I moved forward with the subject.

Beocenter works. During two hours, he did not turn off even once.

The turntable plays nicely.

The radio works and tunes, but it makes a strange low-frequency sound – maybe because it does not have an antenna? By the way, which of the two plugs is better for listening to modern fm?

The cassette cartridge does not work – it arms it and immediately turns it off, it doesn’t want to spin.

And the display works only partially.

A few photos below.

Thank you everyone who got involved in helping ♥

X

[Mark-sf]

Either FM jack is fine as it depends on the type of antenna. If using a dipole wire type you should use the 300 ohm. 75 ohm is for a coax-based external antenna.  Regarding your cassette, have you replaced the belts and check the idlers/pulleys for freedom of movement? As to the display, unless you have bad solder joints if those segments never light up then it is likely the LEDs.

[Xavier]

Thanks Mark!

The radio previously worked on a piece of cable. That’s why I think it’s enough if I order a small telescopic antenna, as on the picture. What do You think?

The cassette player also worked, similar to the display. I’ll start with the diagnostics of the player mechanics.

But before that I will listen to music from vinyl. I am happy as a child : )

X

[Mark-sf]

Glad you are making progress. That antenna is for AM reception though it will work. B&O supplied dipole wired one or one with two hinged rods for FM like this

[Xavier]

That’s nice. They positively surprise me again 🙂

I installed the antenna, but there is still something wrong with FM radio – I hear a low humming voice in the background, like on AM radio, and tuning is poor.

I saw radio voltage calibration in the service manual. Is this the right direction?

[Mark-sf]

Troubleshooting FM sections is difficult without the right test equipment. If you’re getting a hum I would first focus on whether all of the power supply voltages are correct before changing any VRs. It really helps to have a signal tracer or at least a scope so you can check the RF section.

[Author]

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