ARCHIVED FORUM -- March 2012 to February 2022READ ONLY FORUM
This is the second Archived Forum which was active between 1st March 2012 and 23rd February 2022
I won a Beolit 505 that I bidded for mainly to get the red panels, an undamaged antenna (with correct top) and possibly other parts.
The radio was advertised as non-functional but when I turn it on, it does actually play.
However, there is no bass and when I examine the speaker, it seems the cone has seized. I can't move it at all with my fingers. I compared with another Beolit and the cone should move,
How can this have happened? The speaker looks undamaged and the magnet doesn't seem to have become unglued. Could it be corrosion? There are no particular signs of corrosion on the rest of the radio though.
The magnet has become unglued.Push it sideways and it will snap to the side.It can be fixed.
Martin
Hi Martin. I examined the magnet very carefully and it doesn't look unglued. But maybe you are right after all. I'll make another attempt at pushing it.
/Jörgen
It's a common problem. Here are some posts from the old forum about it:
OK, so maybe it isn't worth the effort trying to fix it then. I have two Beolit 600s with working speakers already.
Anyway, I now have found that the magnet and the rear steel plate can be rotated and moved sideways as a unit. I haven't been able to free the voice coil by doing so though. Is there a way to remove the (now loose) magnet and rear plate for inspection?
Yes, pull it off.
Thanks Martin.
With the magnet off (see pictures below) it is clear that the inside of the coil has rubbed against the magnet center. This has caused burr in the aluminum. I wonder if this can be removed without damaging the coil.
There is 0.4 mm clearance between the coil inside and the magnet center.
With the magnet off, the coil/cone moves freely and the outside of the cone seems to be centered in the hole of the front steel plate.
The speaker with magnet off
The coil inside.
The coil.
The removed magnet.