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
As so many before me i've started my BM3000 repair/restore.... Removibg the front snd separating it from the keypcb was about the fidliest work ever.... Is this the common way to reestore these, to totally dismantle it.. Anycase thats more dor less what ive done to get the keyassembly free, need to desolder about two dozen cables... But then ? Do i emerse the whole assembly in isoalcohol and push away at the buttons to desolve the old muck , do i let it soak?.any other solventd i should/shouldn't use?... NoT sure i want to disassemble the pushbutton mechanism..all those springs..not sure i will ever get thst back together..any tips are welcome.
I will upload pix..
Thanx
/g
BM 2000 *1974, 2x BM 1200, BM 1001, BG 1200, BG CD X, BC9500,BM3300,Bcord 3300, BG CD3300, Beovox Cona, Beovox CX100, Beovox 1200, Beovox RL60.2
The best way is of course to take everything apart and clean it bit by bit meticulously but - oh dear - that's a HUGE job inthis Beomaster and less will usually work fine.
I like to spray in liberal amounts of contact cleaner from inside, let it soak for a couple of minutes while operating the switches and then blow out using compressed air. Repeat a couple of times.If left in there the contact cleaner will losen oxidation but it will not remove anything - just shift it around - so you will have to blow it out orremove it in some other way.
Martin
Thanks Martin,
Sounds a lot simpler, is the usual method of refrum on the different PCB to let them stay in the frame whilest messing about? espaecially the bulb on the tuning meter, how would you have changed thatone without taking out the front...
In any case, here are some pictures, the first two is of the donor machine for some parts, a wreck i got for free, screws instead of fuses, and the resulting disaster....the other one from which the other picturas are is a very clean machine indeed, even the trimmers look brand new!
I really cant believe someone would replace the fuses with machine screws!!!
What must they have been thinking of.......I have used "Servisol" switch cleaner to do this fix on a couple of beomasters, Maplin sell it in the UK and they also sell aerosol cans of compressed air to blow out...bit expensive I know...but so is a compressor, I have also used it on the linear trimmers. I have heard people in here talking about the use of "snake oil" and the resultant damage it causes, I'm guessing its a WD type solution to which they refer, as an ICI trained instrument engineer we used Servisol switch cleaner on our instrumentation slide wires and selector switches all the time with no detrimental effect, some of the older guys swore by its healing powers ;¬)
The S-meter lamp is relatively easy to replace.Losen the tuning slider from its string and remove the two screws holding the large tuning potentiometer bracket and swing the whole assy aside.Remove the two screws holding the block of preset potentiometers (fingerwheels) and swing it aside carefully (not to break the ribbon - it's brittle!).Depending on the type of S-meter, you can now either take out the socket and lamp from the right side of the S-meter housing usingneedle-nosed pliers or remove the screw and bronze spring plate and take out the whole S-meter so you can access the small fiberboard carryingthe soldered axial type lamp.
Sounds like a lot of work but it usually takes no more than 10 minutes.
yes, read great thing about Servisol, can't get it in Sweden for some bizare reason, I use this stuff (see link), it does contain a very very thin oil, for slidepots etc, but i used it for contacts in general with some success.. but im unsure how good it is for just disolving without leaving this thin oilfilm
http://taerosol.com/en/7-78-kontakt/
it had the right side access type of "bajonette" lamp... thanks for the tip, for my next 3000 :=) now that it is in molecules i wonder if I shall desolver every connecting wire, so i have freestabnding PCB to work on, or if i shall keep it all togehter and work by turning the whole thing over eacht ime loosening a komponent, the 4400 seems easy in comparison, with all the sockets...
The best contact cleaner in my opinion is one that evaporates completely, rather than leaving "something" behind that merely adds tothe mess already in there.Oil will eventually dry out and become something else. And while wet and sticky it will grab all dust and dirt that comes its way and hold on to it.