hcraig244

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  • in reply to: BeoGram 4000 tone arm problem… #11938
    hcraig244
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    Dillen (Martin) from this site is your man……he can supply the correct lamps for you, send him a line.

     

    in reply to: Bg 4000 tonearm behavior #11799
    hcraig244
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    Just spotted this post justin, picked up a chest infection from soewhere ;¬(

    The tone arm dropping sharply sounds like not enough dampoing, try winding the srew in very slightly…..and I would check out the down switch contact…..if its playing up the tone arm will dot stay up when ^ is pressed

    in reply to: BeoGram 4000 tone arm problem… #11630
    hcraig244
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    Found this in a 2012 – 2022 archived post “justins BG4000”

    Powered up and this is what transpired:

    unit sat powered up with no actions
    upon hitting Start the platter drive started up at 33rpm
    the panel ilumination lamps came on
    the 33rpm speed selector lamp cam on
    However the transport drive motor didn’t run, I could change the speed from 33rpm to 45rpm but no other functions responded. Time to look at the circuit diagrams…… 

    This is what I found….the following components where shot:

     

    1D11 Diode
    1TR33
    1TR31
    1TR30
    1TR32
     

    All of the components on the opposite side of the motor tested good.

    Untitled5

     

    in reply to: BeoGram 4000 tone arm problem… #11612
    hcraig244
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    You may consider checking out diodes 1D8/1D14 also, you could also try exchanging the inboard drive transistors with the outboard drive transistors one at a time and testing as you go….if it is a failed transistor you will get to a point where you lose inboard and gain outboard travel.

    2917877-40

    I invested in one of these…….it has been a very usefull tool over the years, can test transistors and diodes

    in reply to: BEOGRAM 4000 “Training manual” problem #11569
    hcraig244
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    Read on through section 3.21….this gives a full description of the three functions associated with the drive for the transport system, you should be able to test the voltage levels at the associated transistor points when the control panel switches are operated, the notes are a little truncated and “solder ron” may be able to fill in the missing information as they where kindly donated by him.

    Craig

    in reply to: BeoGram 4000 tone arm problem… #11458
    hcraig244
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    Sorry…..i misunderstood your problem, didnt realise everything was fine when playing a record.

    in reply to: BeoGram 4000 tone arm problem… #11352
    hcraig244
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    P1016412 (Copy)

    in reply to: BeoGram 4000 tone arm problem… #11347
    hcraig244
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    Ok…..check this set of switch contacts also…I know i keep banging on about switches but if nothing else you will eliminate them from the search. If these contacts dont operate your motor wont operate as a servo, the contacts should open when the solenoid energises.

    Untitled

    • This reply was modified 2 weeks, 1 day ago by hcraig244.
    • This reply was modified 2 weeks, 1 day ago by hcraig244.
    • This reply was modified 2 weeks, 1 day ago by hcraig244.
    in reply to: BeoGram 4000 tone arm problem… #11247
    hcraig244
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    A very high percentage of problems experienced with these decks result from switches, either on the control panel or the transport slider. A switch out of position be it open or closed will play havoc with the boolean logic control gates, I have chased my tail for weeks trying to locate a problem that turned out to be nothing more than an intermittent sticking contact on a transport slider switch……an issue that had been identified as a possible cause by Dillen at the outset….however as it was intermittent when I tested the switch it worked fine…turned out that the silicone grease i had blobbed onto the plastic nipples (which I thought would help keep them free) was causing them to bind due to the viscosity……thorough cleaning and has worked fine since…….I’m rambling I know ;¬)

    Craig

    in reply to: BeoGram 4000 tone arm problem… #11238
    hcraig244
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    switch2Ok…..start by checking the switch contacts on the carriage transfere mechanism, sounds like this unit has been stood idle for a while, they are a little awkward to get at but sounds to me they will need cleaning even if they are not responsible for your problem. Dont adjust any of the position screws.

    Craig

     

    • This reply was modified 2 weeks, 3 days ago by hcraig244.
    in reply to: BeoGram 4000 tone arm problem… #11231
    hcraig244
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    Dont force it…..let it soak, WD40 isn’t popular on this site (I think the popular term for it is snake oil ) De Oxit is the cleaner of choice, however i would go for something like 3 in one penertrating oil…..leave it overnight.

    Craig

    in reply to: BeoGram 4000 tone arm problem… #11128
    hcraig244
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    Read/view this rom beolover

    https://www.youtube.com/watch?v=IxIxHb8sZdg

    in reply to: What are you working on now? #10845
    hcraig244
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    IMG_2243

    in reply to: Beomaster 4400 – Sudden drop in sound? #10687
    hcraig244
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    Are both your tuning lamps working fine?

    in reply to: Beogram 4000 Restoration Issue #10661
    hcraig244
    SILVER Member
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    Where did you get that lovely Beo Hub board from? I did have to replace a reed switch and a blown transistor on mine (TR6 I think?).

    I have also had to replace the reed switch on a couple of these units, usually after i have invertedly grounded the 6vdc circuit…..its happened a couple of times when the carriage slide has moved too far in when i have been testing with the slider switches removed (schoolboy error)…..

    in reply to: Beomaster 4400 – Sudden drop in sound? #10660
    hcraig244
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    You haven’t said if your measuring a voltage drop when the volume falls down….have you monitored this yet…i so is it falling off?

    If you upgrade your membership to silver you will have access to the service manuals for mostly every B&O amplifier available…….

    in reply to: Beogram 4000 Restoration Issue #10641
    hcraig244
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    Firstly….is the existing fuse blown? no need to replace it if its good….I would buy a couple because often when you take these out the end cap becomes detatched and the fusewire pulls out of the glass holder, the fuse is 0.4A and sits in approx 14vac circuit.

    The high temperature that has discoloured the yellow sleeve is heat generated from the voltage regulator circuit 2D4 (ZF6.8) 2R22 and 2TR6…..the fuse isn’t responsible for generating heat, this discolouration is very common as the regulator circuit does run hot…before you reconnect the fuse check you have the approx 14vac measured between the blue wire connected to the fuse and the blue wire connected to the PCB just above the rectifier…..this will confirm you transformer is giving the required voltage.

    Craig

    in reply to: Beomaster 4400 – Sudden drop in sound? #10538
    hcraig244
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    Made a mess of that…..the table shows the voltages that should be present at TP14 for mute on or off.

    • This reply was modified 1 month ago by hcraig244.
    • This reply was modified 1 month ago by hcraig244.
    • This reply was modified 1 month ago by hcraig244.
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    in reply to: Beomaster 4400 – Sudden drop in sound? #10507
    hcraig244
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    in reply to: Beogram 4000 Restoration Issue #10474
    hcraig244
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    What do you measure on the input and output of the bridge rectifier 2D5 ? and have you checked the fuse hiding inside the yellow sleeve from the transformer to 2D5 ?

    Craig

Viewing 20 posts - 1 through 20 (of 102 total)