1980's Beocord 5000 type4923 very low and rough sound output

1980's Beocord 5000 type4923 very low and rough sound output.

First: I did all the belts. Then the r20 10ohm resistor on the power board and now it physically runs and sounds as if playback speed is correct.

The only audio I get is at very high volumes I get a faint distant sound out of two known working tapes and the sound is crackly distorted. My uneducated guess is the sound is bypassing any preamp in the deck.

I've think I've read every post I can find on the deck or ones that are similar. Touched the leads coming from the head and there was no loud sound or buzzing, just sounded the same.

Cleaned and deoxed the connectors.

I'm an amateur here, read someone replaced caps on the Dolby board so I replaced the 220, 470, 2x 100mf caps. I know enough to put the caps in the right direction and use the appropriate values. Funny thing was the c2 cap installed was a 470mf but the service manual has it as a 100mf. I first tried the 470 then the 100. No change.

Any tips out there? Where

I'm at the end of my diagnostic road. I don't know how to test a capacitor and don't have an oscillator or know how to use one but I do have an analog multimeter and can follow instructions. How else do you go about solving these problems?

Check the relay for playback/record (tapehead) switching.

Martin

Thank you Martin,

How do I test this relay? If this is like testing a relay in a car then I would expect an audible click or pull it out and test it under current.

Also, I'm a big fan of yours here in the reading and studying beoworld archives.

Already on to the next question, how interchangeable with newer products are these Omron g2v-2 34ohm 4.5volt relays? Looks like an exact replacement part is going to be hard to find.

Put an ohmmeter to its contacts. Tap it with a pencil or give it a shot of contact cleaner.
If in doubt replace it. It's often found bad. A 5V type will be fine.

The same goes for the two black Roederstein capacitors with the green lettering right next to it. 2x 470uF if I remember correctly.
And thanks.

Martin

Thank you,

I've put new 470mf caps in and cleaned the relay again. Nothing. Primary survey redone, everything connected, switched, etc. still nothing. Pulled the relay out.

Not totally sure where to test for continuity with these 8pins and the diagram of the relay from the service manual doesn't tell the untrained which connections correlate to which pin. Trying different combos with manipulation of the inner contacts is still leaving me nowhere.

I'm assuming the relay is my source of troubles now. I found somebody in Lithuania selling untested replacements. Little more complicated than my car's blinker relay.

How tolerant of spec changes are these relays if I buy something else? Or should I just try to buy a parts unit bc5000 and hope for a working relay?

Thanks again for your advice,

Learning in progress here. Relay is good. Continuity between pin 4& 6, 13&11. 9v current to pins 1&16 gives me discontinuity between 4&6, 13&11 but now continuity between 4&8, 13&5. From pictures online of other 8pin 4.5v relays this is a common format. Also if someone else is trying to find a replacement, emailed Omron about the relay being out of production and they state that the g2v-2 4.5vdc is replaced by the Omron g5v-2 4.5. So I will order a replacement and test the relay once it is reinstalled. And I see and hear connection. Maybe the contact cleaner had to soak in.

So if my relay is good what's my next diagnostic path? This has been a good learning exercise on a deck that was headed for the trash.

Relay arrived in the mail this morning, installed while the coffee was brewing and hurray! The Beocord works! Two months of trying and testing and studying and waiting for shipments from Asia and Europe. Thanks to Martin for his expert advice in this thread and his advice over the course of years to other members that are so amazingly archived on this forum.

Pictures of the relay used from recommendation of Martin and the Omron representative, and a picture of it installed for the reference of the next person working on one of these.

Good job!
Haopy I could help.

Martin

And thanks for posting the positive result, often people forget that.