I have this older type Beomaster 2000 I managed to fix up from a parts machine, but later the tuner suddenly failed; all I can get is static from all the presets and the main FM dial (AM probably works, but we don't have anything worth receiving over here so I can't really tell from all the computer and switched mode PS noise).

I measured the power supply and test point voltages I could get to, and they seemed OK. The IF detector/amplifier TCA420A seems hot to the touch - is this a likely failure point? I have another working unit for comparison,  but since the covers are a b*tch to get back on correctly, I thought I'd ask first...

Replace the rectifier (D8), it will be bad, put in a B40C1500 or similar and while at it, you might as well replace the 470uF cap right next to it, it will also have seen it's best times. Check that the five lamps are of the correct type since wrong lamps will put too high loads on the driving transistors, they will be hot enough with the original spec lamps.

- Or just grab a kit containing new lamps, new rectifier and a small fix to make the lamp circuit work as B&O intended.

You didn't break any of the leads going to the tuning cap/potentiometer on the top panel ? Do the FM presets work ?

Martin

Thanks for the hint - the old rectifier measured OK, but I replaced it anyway (and the cap) - no change. All the power supply voltages are OK and so is the tuning voltage, both from the dial and presets. I have replaced the bulbs with presumably correct types earlier. TCA420 still thinks it has no IF (pin 10 stays at ~0V). Time to haul this machine to the oscilloscope and see if it's right.

If the front end proves to be at fault, I don't think I'll bother investigating further - this unit is missing some buttons and is also cosmetically challenged otherwise. Makes a great amplifier though