Hi I'm about to crack open my Beomaster 4000 for the first time to do cleaning it was very dirty outside I'm sure its worse inside. What things checking and what needs maintenance. Where should I start? It has very scratchy controls and crackly buttons and the balance control has to be moved lots so both stereo channels come in. The Bass control doesnt seem connected inside and won't change the Bass. The lights light up but seem dirty and dim. What oil or lubricant do you use on the moving parts? I piece of vaneer is missing from the edge of the radio,top and bottom. I have the service manual so I can find things and locate parts. Thought or ideas.

I'm doing my BM 4000 now, here, I recommend to get a lamp and capisitor set from Martin (Dillen on the forum), before that check all your trimmers and output  transistors, as well as the 3 big 5000 Mu caps, the sliders are kind of open and with a pipe cleaner bend a little, its posible to get in and clean with some iso alcohol.

Also when open check the no load current before ordering parts, easiest is order from Martin, then you get it right.

In the manuels onsite, there is an upgrade description for the output stage, in my eks. it was done only partly, the 2 0.15 Ohm was upgradet to 0.30 Ohm, i will ask Martin if I have to do the rest.

There are no points needing lub, just clean it properly

And for your missing preset cover, search the forum, someone made a good thread about it.

As you are in the US I presume you got the US version with 108 Mhz, type 2408.

I will order my parts from Martin tonight, if you hurry up with checking and ordering maybe we can do a joint venture, the guys here on the forum has nothing to do, in vintage, at the moment, so we will hit a good spot to get help where needed.

Good luck and lets get rolling.