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
On the surgerytable lies now a BM1900, donated to me from a friend ( in order to use as source for parts swap with my own 1900 that during playing suddenly fell silent) that is still alive but not kicking: it sounds great although the tone section, sliders and lamps, “says no”.
I found a thread about replacing lamps by LEDs, which I used to apply to the newly acquired 1900; not yet tested on the spot because I took the challenge of trying to open up the sliders and see what is in them.For possible education purposes and mainly for my own fun, despite arthrosis in my fingers and one malfunctioning eye ( I am not gaining for pity) I managed to discover what went wrong with the 3 sliders. See pictures. Will follow later( first reducing size of the .jpg), when I continue this thread, if it is OK to followers.8
Potentiometer repair kit:
https://beoparts.com/2018/01/13/beomaster-1900-2400-potentiometer-repair-kit/
LEDs won't work. The lamps are integrated parts of their respective circuitry, which is depending on the lamps resistance and current flow.
Martin
Before attacking the LEDs issue first trying to get the sliders (balance, bass and treble) fixed.
In all three I found the small brass tips either loose or deformed; a scrap BM 1900 served as donor for the repair session. So I took a deep breathe and at the same time holding it ( very often) and these are the results.
To put it back in place !
It did not hold the first time , so to desolder the slider, opening it and redo the gluing
The original plastic material contains a large amount of oil.Glueing it is practically impossible. It won't hold for long because of the static pressure from the bronze contacts.
I cleaned the particles from grease and furthermore if it holds depends on the kind of glue. So far so good: the 3 sliders do now what I expect them to do. Anyhow I gave it a try; it was at least an exercise in miniature DIY particularly in respect of my previously mentioned physical restriction..
The faulty lamps have been replaced by LEDs , not in the tuning- and volume indicators as Martin adviced.
Now I go back to my other BM1900, that played without any problem until the other day when I moved it from table to shelf: I heard a loud humming and noticed that the left heartsink was kind of loose. When I maninpulated that thing there was one short loud hum .I switched it off immediately and now I do not dare to switch in on. There must be a short some where.What now?
Aad
(Sorry about twice the picture at 9:11: there was a Hackers warning from Beoworld when I tried to post it, but obviously it did come through.
If the plastics turn out to be problematic, send me a complete, assembled donor part and I'll do my best to model a replacement. I'm still on the hunt for a reasonable 3D printing place, but some of these smaller parts will be doable and should last long enough with my printer here.
Or....just get the replacement plastic bridges from Martin that he already provided a link to. :-)
I can vouch for the repair kit as I have them on several Beomaster 1900 and 2400 restorations now.
-sonavor
I will keep all this in mind; so far I am confident that my surgery will sustain the working of the plastic parts: if not I have Martin’s e-mail address.
Thanks for your reactions.