H3NK3L
Member (SA)
New project , scored a prett dirty, not working, humming on one channel,.... Brandt RK813S - aka Sanyo M9998 (for the french market)
had quite a few issues :n
- the usual black stuff that used to be tape belts
- FM radio totally offset , only going from 99.x to 105.x
- constant humming on the right channel (a transfo like sound)
- tape door remaining open
- no apparent power to the the tape deck
-...
Started out with totally dismantling the whole device, cleaned tape deck and replaced belts (not easy but easier than on a M9998), fixed the tape door problem - on these the tape lock mechanisme has 2 moving parts : tape presence detector + tape lock, the tape lock actually is a contactor...so cleaning that solved the "no power to tape deck" issue. - regulated the tuner....which is actually tidious but not that difficult on this one ... . It has the same tuner light system as the sanyo, meaning : sanyo has this black backplate system with a perspect tuner dial imprinted plate with a hole for the light... Btandt went the other way on the same system : a metal plate with the imprint on it (no perspex), and the hole for the light....but a piece of cardboard glued behid the plate to achieve same thickness as the sanyo. Result : the light doesnt do much except be there... So while at it I replaced it with 4 leds, which 2 by 2 I put in thetubing of an empty windex spray , thus creating 2 "light tubes" which I put on both ends. Took some time to figure out why they were CONSTANTLY on... in the end...cut the orange wire...and put on on/off button between the blue and white one (resp on the power switch and the dial light/batt check switch). This way : the original dial light/batt check switch works as intended (light on when pressed, leds to indicate battery) + a permanent button for dial lights I added. When that is on, the batt check still fonctions. while added and for the love of symmetry I added a 2nd button for bluetooth (through AUX din input) - symmetrical to the original power and dial light switch.
Still had the constant humming ont he right channel...checked the circuitry and couldnt find any issue...on the input side...on the the output side however..there was a constant 25 mV signal to the right channel.... so after replacing all caps near to the heatsink or in in its proximity...I replaced the right channel power amp chip and look and behold...no more humming....created a new issue though : left channel being weaker and sounding less "warm" than right, therefore put in a NOS amp chip in there as well and now we have a fully working, clean, bluetoothed, lighted device, with the typical warm and very clear sound sanyo has gotten us used to.
BTW : this thing doesnt look like it but its actually quite huge and heavy (behind it on the table is a Sanyo M9998 for comparaison, its about just as wide and only slightly less high - power though is not the same, its a 2x5 W (7w max continuous), but it goes real loud and has great bass
The tape deck itsself is exactly the same as on the M9998, but (only just) slightly more accessible for replacing belts : remove the bass/treble/volume "block) (one screw right hand side, 2 left hand side + remove the 3 screws holding the tape block in place (2 bottom, 1 left hand upper side), remove the 2 little screws on the back of the tape deck (holding the logics buttons and the pcb), then you can slightly slide out the deck, remove 2 screws on the triangular plate covering the flywheel, replace belts (flat one firstt - while at it : check motor hight and its 3 rubbers), dont forget to use something to hold the screws in place (nail polish. locktite,..) when re-assembling and take very very very good care to tuck all the cables back so they cant toucht any moving parts of the deck).
On these decks, whatever you do... DO NOT insist when especially the REW button doesnt seem to want to go down ! its mechanically held back when the tape presence / locked door detector mechanism is out (that is the little white square thingy on the middle right side of the tape deck, if it sticcks out : push it so it goes in, its like a button, it will "unlock" the piano buttons of the tapedeck. I you were to insist you would possibly break the piano buttons of the tape deck.
had quite a few issues :n
- the usual black stuff that used to be tape belts
- FM radio totally offset , only going from 99.x to 105.x
- constant humming on the right channel (a transfo like sound)
- tape door remaining open
- no apparent power to the the tape deck
-...
Started out with totally dismantling the whole device, cleaned tape deck and replaced belts (not easy but easier than on a M9998), fixed the tape door problem - on these the tape lock mechanisme has 2 moving parts : tape presence detector + tape lock, the tape lock actually is a contactor...so cleaning that solved the "no power to tape deck" issue. - regulated the tuner....which is actually tidious but not that difficult on this one ... . It has the same tuner light system as the sanyo, meaning : sanyo has this black backplate system with a perspect tuner dial imprinted plate with a hole for the light... Btandt went the other way on the same system : a metal plate with the imprint on it (no perspex), and the hole for the light....but a piece of cardboard glued behid the plate to achieve same thickness as the sanyo. Result : the light doesnt do much except be there... So while at it I replaced it with 4 leds, which 2 by 2 I put in thetubing of an empty windex spray , thus creating 2 "light tubes" which I put on both ends. Took some time to figure out why they were CONSTANTLY on... in the end...cut the orange wire...and put on on/off button between the blue and white one (resp on the power switch and the dial light/batt check switch). This way : the original dial light/batt check switch works as intended (light on when pressed, leds to indicate battery) + a permanent button for dial lights I added. When that is on, the batt check still fonctions. while added and for the love of symmetry I added a 2nd button for bluetooth (through AUX din input) - symmetrical to the original power and dial light switch.
Still had the constant humming ont he right channel...checked the circuitry and couldnt find any issue...on the input side...on the the output side however..there was a constant 25 mV signal to the right channel.... so after replacing all caps near to the heatsink or in in its proximity...I replaced the right channel power amp chip and look and behold...no more humming....created a new issue though : left channel being weaker and sounding less "warm" than right, therefore put in a NOS amp chip in there as well and now we have a fully working, clean, bluetoothed, lighted device, with the typical warm and very clear sound sanyo has gotten us used to.
BTW : this thing doesnt look like it but its actually quite huge and heavy (behind it on the table is a Sanyo M9998 for comparaison, its about just as wide and only slightly less high - power though is not the same, its a 2x5 W (7w max continuous), but it goes real loud and has great bass
The tape deck itsself is exactly the same as on the M9998, but (only just) slightly more accessible for replacing belts : remove the bass/treble/volume "block) (one screw right hand side, 2 left hand side + remove the 3 screws holding the tape block in place (2 bottom, 1 left hand upper side), remove the 2 little screws on the back of the tape deck (holding the logics buttons and the pcb), then you can slightly slide out the deck, remove 2 screws on the triangular plate covering the flywheel, replace belts (flat one firstt - while at it : check motor hight and its 3 rubbers), dont forget to use something to hold the screws in place (nail polish. locktite,..) when re-assembling and take very very very good care to tuck all the cables back so they cant toucht any moving parts of the deck).
On these decks, whatever you do... DO NOT insist when especially the REW button doesnt seem to want to go down ! its mechanically held back when the tape presence / locked door detector mechanism is out (that is the little white square thingy on the middle right side of the tape deck, if it sticcks out : push it so it goes in, its like a button, it will "unlock" the piano buttons of the tapedeck. I you were to insist you would possibly break the piano buttons of the tape deck.
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can you get me a pump lad lol
