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
Just picked up a BeoMaster 1900-2 in full working condition except for the lamps. A lot of those did not work (volume up, bass, treble, balance, radio 2, radio 5 and dial lights).
Removed top cover to replace the lamps and even before doing anything at all touch doesn't work anymore.
Power comes on (stand by light working), but that's all. Did I break something, and if so, where?
Any help appreciated.
You didn't assemble it correctly. That's very common.A bunch of bronze spring contacts needs to grab each their tiny pin on the underlyingcircuit boards, not an easy task.
A lamp kit is available, it comes with a complete set of fresh and correct wattage lampsplus instructions for (dis-)assembly with photos and english text.The lamps are soldered in but if you have a standard electronicstype soldering iron, basic electronic tools, screwdrivers etc. and a little skill, you will be able to do therepair and lamp replacement yourself.
We are not allowed to advertize our own listings on Ebay, Bonanza and the likes but you cangoogle "Lamp kit for Bang & Olufsen Beomaster 1900" and you will get the idea.
Martin
Martin,
Thanx for the quick reply.
I do a lot of repair on vintage electronics (just finished a BeoGram 6000 and a BeoGram 1600). All lips are in the proper position, so I suspect it's the lamps. Could you confirm blown lamps can cause this? If not, I'll have to spend some evenings to check caps and resistors with a scope.
Will check out your website.
Adam.
I suggest you check those bronze forks again, you can see them from below the front, with the bottom plate off.There could be other reasons for the sensor pads to stop working but this is by farthe most common reason and the fact that you just had the front panel off only addsto the suggestion.
Blown or wrong wattage lamps can cause many strange faults but usually not a completedisfunction of all sensor pads.
Bonanza is not my website.
Will do.
I know bonanza is not your website... like eBay is not mine. Would be nice tho. I'd love to go sailing with Richard Branson every now and then .
OK. Cleaned the pins (touch pads reacted 'jittery') and realigned the forks. Those are all fine now, and work properly, except for volume control which was flakey to begin with (very slow volume down; instant volume up to max). TR28 and TR27 have small burn blotched and are smelling. The 1900 diagram (for the 2903 model which is what I have) is driving me nuts however. TR28 should be a BC327, but is a BC558B. TR27 should be a TIP32A(???) but is a BC549B. Or is the 1900-2 (2903) a different one?
And boy was I stupid. Desoldered red, black and yellow wire from volume board and disposed of my 'jot-down' sticky with info on how to connect those :-(.
Any help is appreciated.
Servicing B&O is like nothing else. I don't know how skilled you are but it's not someting I would recommend for starters,There are countless small production changes etc.,not all are documented and I still haven't seen aservice manual and/or schematic without typos and other mistakes.Beomasters of this series came with two (very) different volume control boards; a 16-step version and a 128.
Martin. Thanx for the quick reply.
I don't do this for a living, but managed to fix 3 TEAC A-H500's, a Beogram 1600 and Beogram 6000 this year. Without proper schematics I would not have been able to fix those either.
Will replace with same parts and see where it ends...