Beocord 5000 Type 49xx no sound

[davidross222]

Tape mechanism works but record/play relay fails to pick when play pressed, so no sound.

[TJames1901]

Have you opened the player up?

[Dillen]

The record/playback relay should only draw when record is pressed.
Do the VU-meters react while playing a tape?

Martin

[davidross222]

Thanks, Dillen.

From the circuit I thought RL101 needs to pick for play.  No, nil display on VU’s when recorded  tape running.

[davidross222]

Thanks, TJames for your reply.  Yes, opened and replaced a number of darlingtons in circuit around RL101.  No VU’s on recorded tape.  No change on micro pin 36 !REC.

[Dillen]

Check the supply voltages to the Dolby ICs.
Particularly the Vref (a dead C2 wouldn’t be a first).

Martin

[davidross222]

Thanks,  this deep electronics is daunting for an old bloke!   But B&O have made any servicing a delight!

I will check voltages around the Dolby ICs.

And your suggestion of Vref will be done, too.

davidross

[davidross222]

Sorry for delay in answering, Martin!  Thanks for the leads.

Checked all voltages including 14a around Dolby board.  All present.  But worst possible result for fault – after reassembly it works perfectly!!  Tested now with many tapes both in playback and record.

Guess I just wait for something to show up some day … sigh

[davidross222]

New thread:  what is best solvent to remove the gunk left by perished belts in tape drive??

[Dillen]

davidross222 wrote:

New thread: what is best solvent to remove the gunk left by perished belts in tape drive??

IPA.
(Isopropanol alcohol, that is. – Not the beer).

Martin

[davidross222]

Thanks, martin.  But I need to buy some gloves first, because NOTHING gets the awful stuff off your skin!

David

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