Beocenter 9500 No Output / Weak Right Channel

[Dustin Ortegon]

Greetings All!

I just picked up a beautiful Beocenter 9500, my first B and O product.  I brought it home to do initial testing of the unit, only to find that the Main Passive Speakers have NO output, the Secondary speakers have Left channel and a VERY faint Right channel.  Headphone output is the same.  Left Channel is good.  VERY faint Right channel.  (Basically sounds like an unamplified signal)

Before I tear into this thing, I want to reach out to the experts.  I am thinking the muting relay is probably to blame for the dead main speakers, and possibly the STK IC for the Right channel issue.  If you experts have any other ideas I would appreciate it.

Thanks!  Oh, and the Powerlink sockets work with amplified speakers.  No issue there.

[Guy]

Hi and welcome to Beoworld!  The BC9500 is a great first purchase.

First thing to check is simple:  Are you sure that there isn’t a 3.5mm to 1/4 inch adaptor in the headphone socket?  Sounds silly but this mistake has been made many times in the past!

EDIT:  But if the headphone output has the same problem this is unlikely – apologies!

[Dustin Ortegon]

Thanks!  It really is beautiful.  I saw it at the estate sale with a matching Beogram 9500 and had to have it. (Even though it was completely unneeded.  LOL)

No adapter installed.  I used a 1/4 inch plug to test my headphones.  But I appreciate simple troubleshooting before tearing into a unit.

[lausvi]

The muting relay is a likely suspect (trigger it on/off several times to see if there is any improvement).

Check if the “dummy plug” is installed in the LINE IN/OUT on the rear connections panel (if removed, the pre-amp signal won’t be going to the main amp, although this wouldn’t explain the partly working secondary speaker output…).

Also check the BALANCE adjustment.

[Dustin Ortegon]

I triggered the “Mute” a few times, I didn’t hear any clicks of a relay activating.  As far as the Line In/Out plug, it is installed.

The Balance seems to operate correctly.

Thanks for the response.

[Dustin Ortegon]

Update: New relay at R1 installed and no change.  Main L+R passive, no audio.  Secondary R is good.  L is weak.

Any ideas from experienced B and O techs?

[Dustin Ortegon]

Update:

Replaced TR22 and now the mains have audio.  Main and Secondary Right Channel is GOOD.   Main and Secondary Left channel is WEAK.

I am leaning towards an STK module.  Do these regularly go bad?

Thanks!

[Author]

Posts