Beogram 4000 record detection issue

5 replies
Hi All, working on my BG4000 which does have record detection issues: first the detector arm bulb dies not come on ? It measures about 40 ohm and is getting 6.3V supply when ON is actuvated. checking the collector voltage at 1TR14 I should see a max of 2.2V  - the max I see is 1.6V. Both, 1TR14 and 1C9 have been tested off board as good ?? what am I missing here and why isn’t the bulb illuminated ?? help would greatly be appreciated ?? ALF
Hi Alf As the bulb is measuring about 40 Ohm it should be OK. Check 1 R 30 (15 OHM) and all tracing connections. About Transistors which are measuring off board in a good state.... If I pull one of these little BC5XX Transistors out I always put a new one in, cost only 5 to 20 cent and you're shure that the new one will work. Had already a lot of them measuring good, but a HFE about 20 or 100, too low in that case. Hope it will help a little bit. Kind regards Christian
Hi Christian, thanks for the input, very much appreciated. R30 measured 14.9 ohm ! i revisited that detector bulb, definitely not lighting up, so I put a “replacement” that lit up straight away as expected when 6.3V are present. However that “replacement” is not the correct bulb - my hope is Martin (Dillen) can supply a correct one ?! ALF
Alf Does the record detection circuit work with the replacement bulb....or are there still issues? Craig
Hi Craig, it worked before the original bulb went dead. The “replacement bulb” has a different filament type - it lights up but does not produce the correct light circle.p through the lense. the correct bulb has been ordered from Beoparts shop yesterday - now its the waiting game until it arrives. ALF  
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