Marantz PMD221 - most units that are sold as not working will have a burnt motor governor, a burnt headphone amplifier and 2 blown capacitors; parts are readily available; - a new belt set will be needed if the unit has a lot of hours on it; when replacing the belts, a relubrication of the rotating parts is also necessary; - there is a crosstalk between SOURCE and TAPE when recording on this unit, which is a design limitation; this makes the recording monitoring functionality more or less useless, because the crosstalk will distort the signal badly being out of phase with the source; - noise floor is much better than the PMD430, but that is mostly because this is a mono unit and because of low bandwidth; - the headphone amplifier has a lot more drive capability compared to the PMD430; - frequency response is pretty bad, I'd say at the limit of usability (12kHz on a TYPE I tape, 14kHz on a metal); cassettes played on this units sound audibly muffled; same on recordings;
Sony WMF63/F73 - almost impossible to find a functional unit unless recapped. - Sony used the worst capacitors on this model, So Capacitors must be replaced.
Panasonic RQ-WJ1 - PCB board is fragile (So if you decide to work on this model make sure not to accidentally bend the flexible board - almost all units have heavy capacitor leak on the board - list of capacitors needed to be replaced: 22 uF 6.3V 1 220 uF. 4v 4 10 uF. 16v 1 100 uF. 4V 3 47 uF. 4V 2 4.7 uF. 25V 1 470 uF 6.3v 1
Toshiba KT-AS1, Toshiba KT-RS1 - slider buttons for DOLBY (on/off ) and tape selection (NORM/Metal) is fragile and breaks during belt installation. Be careful not to break it. - a crack in the FFW and REW spool is very common in these models (and most of Toshiba walkman units) - Its common to see a dry potentiometer/ volume pot on these models.
Dudes, WOW! I feel like I am contaminating this thread (BTW, it just MUST be Pinned!!!) but the thought of doing the same for Discmans makes me cringe: I do make notes on each of my revivals but the pains of going through the notes is NOT fun at all! You guys are my Heroes!
SONY WM-DX100 - common problem with reverse pinch roller having an indentation mark; this is caused by engaging the mechanism without a cassette in, which confuses the microcontroller and sometimes the unit remains in reverse even when stopped. Both rollers should be replaced, as this will decrease the wow&flutter significantly; parts available at fixyouraudio: https://fixyouraudio.com/product/pinch-roller-6-x-5-x-1-5-mm-for-cassette-players/ - rotating parts of the mechanism need cleaning and lubrication: capstan bearings, gears (on these replace grease with oil). Not every single gear can be taken out, on those that cannot be removed put a small drop on the shaft and rotate until the oil gets inside; Some of the gears are hard to turn, that's why I really recommend doing the lubrication on this model; - belt will need to be replaced for sure, replacement available at fixyouraudio; On this unit expect a wow&flutter figure typical to belt-driven units; the disc drive section is used solely because the unit is very thin and the FG coil could bot be fitted inside the motor, hence it's fitted under the disc; - servo will need adjustment after belt replacement: there are 2 adjustements one with PLL disconnected, another with it connected; - Dolby levels need adjustment; - buttons in the cassette door may need cleaning with contact cleaner; - if unit was left with gumstick battery inside, expect significant corrosion on the battery terminals; Dolby adjustment: 53mV RMS (no load) at the indicated points (see service manual) with 200nWb/m ANSI tape
SONY WM-701C/WM-F701C/WM-702/WM-F702/WM-703/WM-F707/WM-R707/WM-EX80/WM-EX85/WM-FX85/WM-508/WM-600/WM-805 - motor lubrication problems; if motor is noisy, you need to disassemble it and lubricate: https://stereo2go.com/forums/thread...-type-motor-in-sony-walkmans.7943/#post-59754 - logic control buttons will need cleaning for proper operation; it is necessary to disassemble and clean with contact cleaner and cotton swab, just spraying cleaner and pressing will not be enough; Typical symptom is erratic behavior: unit will go into FF when pressing STOP, into PLAY when pressing FF, etc. - on some units it may be necessary to add a small piece of tape over each button, in order to reduce the force necessary to engage them; - volume potentiometer and switches (Dolby, EQ, DBB) will need cleaning; - pinch rollers may need replacement, which is available at: https://fixyouraudio.com/product/sony-wm-702-pinch-roller-tire/ - new belt can be found at: https://www.ebay.com/itm/224109367674 (I recommend the DeckTech belt for this unit as the FixYourAudio one is a bit too large). - gears near the table reels will need cleaning and re-lubrication; - middle black pulley will need re-lubrication; - capstan bearings will need re-lubrication; - capstans are prone to rust: if it's only light rust it can be sanded (1000 grit, then 2000 girt) then roughened with ferric chloride; if it's deep the capstan/flywheel assembly will need to be replaced; - a general re-lubrication of the rotating parts is recommended;
Cybernet PS-202 MiniConcert/AKAI PM-R1/AKAI PM-R2/TEAC PC-7RX There are 2 models of Cybernet MiniConcert: one that looks like the Infinity Intimate and one that looks like AKAI PM-R2/TEAC PC-7RX. Here, I am obviously reffering to the latter. All these 3 walkmans are mostly identical and designed by Cybernet, the only major difference in them is: the Cybernet has no Dolby, AKAI has Dolby B and TEAC has dbx (so a different noise reduction IC or the absence of it entirely). - CE brand capacitors leaky; despite I only found some specific values to be leaky, it's a good idea to replace them all. Also clean the PCB thoroughly and repair any corroded traces. - volume potentiometer needs cleaning with contact cleaner; DON'T use things like WD-40, even the one adverstised as a contact cleaner as it's not intended for this purpose; - mechanism will need relubrication as some gears will have dried grease on their shafts; I recommend using watch oil after cleaning, not grease; - EQ and mute/Dolby/dbx switches will need cleaning with contact cleaner; - problem with azimuth variation from FWD to REV. Solution is to add a very thin plastic washer (sand it down to ~ 0.1mm and enlarge inner hole to 2mm) below the C clip that hold the head assy. - a new belt will be needed; DeckTech sells one exactly for these models (1mm thickness square cut); - possible problem with FF not working; cause is head wire is not in a correct position, not allowing a lever to move to its intended position; - FF/REW not working at all due to stuck gears (old grease); NOTE: I recommend replacing the battery wires (twisted together), as there is a risk of fire if the isolation is pierced when cover is put back together as it's a very tight fit. Recommend routing the new wires so as to avoid the risk and also don't twist them together.
SONY WM-EX90/GX90 - potential problem with clutch slider, which does not sit straight and will cause gear noise when running; solved by adding 2 washers from Marian's washer kit; - motor may need lubrication if it's noisy; same type of motor as WM-700 series; Tutorial here: https://stereo2go.com/forums/thread...-type-motor-in-sony-walkmans.7943/#post-59754 - all microswitches need cleaning with contact cleaner; - the front logic control buttons will need cleaning with contact cleaner; - pinch rollers are likely to need replacement; they are the same as WM-700 series; You can buy them here: https://fixyouraudio.com/product/sony-wm-702-pinch-roller-tire/ (you need to buy 2 pcs, it's not a set) - the GX90 has some surface mount electrolytic capacitors, that are prone to leaking and will need repalcement; Thanks @Emiel for providing this information ! Belt: 70mm x 0.6mm (inner diameter x thickness) - https://fixyouraudio.com/product/rubber-belt-70-0-6-mm-square-shaped/
SONY ZX-7 - rubber needs to be restored or replaced (note that not all rubber parts are available); - rotating parts need cleaning and re-lubrication; - CP601 servo hybrid module must be de-potted; it's identical to the WM-D6 one, so if speed problems happen 2 transistors will need to be replaced; - cleaning of leaf switches, REC/PB switch, mode switches, EQ sliders and potentiometer are also necessary; - flywheel thrust play and motor position need to be adjusted; - adding a 9V regulator to the power supply is recommended, since the supply is unregulated; Idler tires: 1 pcs 17 x 13 x 2mm (outer diameter x inner diameter x thickness) 2 pcs 13.5 x 9.5 x 1mm (outer diameter x inner diameter x thickness) Belts: 1 pcs 31 x 1mm (inner diameter x thickness) 1 pcs 36 x 0.5mm (inner diameter x thickness) Pinch roller: TPS-L2 type
Panasonic/National RX-2700 - mechanism is identical to the Infinity Intimate Stereo, AKAI-PM01, Cybernet MiniConcert/Intimate, the extra parts being the recording erase head; - the spring that tensions the clutch assy must be shortened, otherwise the takeup torque will be very low to non-existent; - the idler tires must be sanded and cleaned: there are 4 of them 2 on the table reels and another 2 on the FF/REW clutches; - the clutches may need repair as the upper plastic part breaks: solution is to glue it to the bottom part (don't try to glue the break it won't hold); - leaked CE brand capacitors are to be found exactly as in the Infinity Intimate: all 3 boards have leaked capacitors so just replace all of them; - corroded traces/vias can happen, so if after recapping the baord some functions do not work, examine traces carefully and measure continuity in key points; - pay attention when removing the front part of the case as the hand hook screw must be loosened, otherwise the small PCB will break; - pay attention when removing the 2 flat-flex connectors: the radio one must be desoldered from the radio board, while the servo one from the main board; - pay attention to the spring that un-latches the REC/PB switch: it must be installed after main PCB is installed from the radio compartment; Belts: capstan 90 x 1mm clutch 38 x 1mm counter 38 x 0.5mm Pinch roller: TPS-L2 type
JVC CX-F3K/CX-4 & AKAI PM-R5 - mechanism will need a cleaning and re-lubrication of rotating parts; - motor will need to be lubricated; - belt will need to be replaced, you will need to get it by dimesnion as there is none made specifically for this device; - capacitors might leak on some units, inspect carefully for any leakeage; Note that you do NOT need to remove the radio scale and AM antenna in order to remove the PCB. The PCB comes out toghether with scale and AM antenna as an assembly. Belt: capstan 67.5 x 1mm (inner diameter x thickness)
SONY WA-8000/WA-8200 - mechanism will need a cleaning and re-lubrication of rotating parts; - all switches will need to be cleaned with contact cleaner; - rubber tires will need to be cleaned or replaced; - motor top bearing needs to be lubricated with watch oil; - pinch rollers may need to be replaced; This is a step that only requires the door to be removed, so can be done after the restoration of the unit. NOTE: Switches to be cleaned include REC/PB switch, REV/FWD switch and leaf switch. For mechanism servicing, I recommend removing the front cover, top cover, leaf switch and desoldering the motor ground. This way you can tilt the mechanism 90 degress and work on it without fully removing from the device. Belts: capstan: https://fixyouraudio.com/product/belt-sony-wa-8000/ counter: 36 x 0.5mm (inner diameter x thickness) Pinch rollers: TPS-L2 type Idlers (2pcs): 8.5mm x 4mm x 2mm (outer diameter x inner diameter x rubber thickness)
JVC CQ-22K/CQ-11K Mechanism is identical to the one presented in post #30 (apart from motor being in a different position), so it shares the same problems. - FF/REW will not work due to old grease; I recommend relubricating all the rotating parts of the mechanism; - motor needs to be lubricated on both bearings; - play in the head carriage assembly will create a situation where azimuth is different in FWD compared to REV. Solution is to take a nylon washer (https://fixyouraudio.com/product/washer-set/) and sand it down to ~0.1mm thickness. Inner hole needs to be enlarged to a 2mm diameter with a drillbit. Then install this washer under the C clip that holds the head assy in place (the one near the buttons). Lubricate the area with grease. - gear teeth require cleaning, so check if there is any debris and clean; - leaky CE brand capacitors, all need to be replaced despite only some particular values may have leaked (there are only a handful of electrolytic capacitors on this one). - switches/pot need cleaning: tone, ON/OFF, REV/PB, volume potentiometer. I recommend Kontakt 60. Pay careful attention when removing the PCB, volume potentiometer needs to come throught the front (where the PLAY, FF, REW buttons are) and tone plastic switch is better to be removed in order not to damage the actual electronic switch. Belt: 87.5mm x 1.2mm (inner diameter x thickness)
Grundig BeatBoy 80 For the most part, the mechanism only needs basic maintenance items: - cleaning and re-lubrication; - new belts; - potentiometer cleaning; Capstan belt: 27.5mm x 1mm (inner diameter x thickness) Clutch belt: 32mm x 1mm (inner diameter x thickness)
SONY WM-100/WM-100 mkII (WM-102)/WM-100 mkIII (WM-103)/WM-F100/WM-F100 mkII (WM-F102)/WM-F100 mkIII (WM-F103)/WM-F203/WM-F404/WM-51/WM-504/WM-F501/WM-F606/WM-F107/WM-51/WM-R202 Shares table reel design with WM-10 series mentioned on previous page at post #17. The good part is the table reels themselves are much easier to remove, not requiring to disassemble the entire device. The overall design is much better, hence why many of these devices will get away with a basic service. The WM-500 series use a different DC motor which does not have a hole for bottom bearing lubrication. These also use an amorphous head. The maintenance items are as follows: - new belt and belt path cleaning; it requires a thin 0.5mm belt which can be found at both FixYourAudio and DeckTech; - corrosion in the battery compartment is common, but despite this damage can be serious; - gear train near the table reels will need to be cleaned of old grease and re-lubed (I recommend watch oil); - all switches (including the 2 leaf switches) will need to be cleaned with contact cleaner (I recommend Kontakt 60); - the 2 leaf switches may need sanding (I recommned 2000 grit sandpaper), it's a problem that exists on WM-10 series as well; - pinch rollers may need to be replaced depending on condition; new ones are available from FixYourAudio; - pinch roller hubs may shrink on some units, making the use of new roller impossible; Solution is using these rollers instead: https://www.ebay.com/itm/125756456667 - motor bearing may need lubrication, but it's a less common problem compared to WM-10 series; - azimuth instability problems are relatively common on these, which can have more than one cause: not straight capstan bearings, bent head bridge, bent pinch roller holding pin; - bent head bridges and pinch roller holding pins are common, causing azimuth instability. Solution is to straigthen the bridge, reinfornce it with some glue and also bend the head bridge spring so it's not that stiff anymore (otherwise bridge will get bent back in time). Dolby adjustments: WM-100 series, WM-200 series - 100mV RMS (no load) at indicated points (see service manual) with 200nWb/m ANSI test tape WM-500 series - 25mV RMS (no load) at indicated points (see service manual) with 200nWb/m ANSI test tape
Koss MusicBox A walkman with unique mechanism design which features feather-touch play button but no logic control. The unit looks to be manufactured by Sanyo and based on the Sanyo M-G1 model, however the latter doesn't have Dolby NR so electronics side is not identical. Main problems with this unit are leaked capacitors, corroded traces on the PCB and old streched belts. Repair and maintenance goes as follows: - all electrolytic capacitors should be replaced; not all of them will have leaked, but all should be replaced regardless; - the PCB needs to be cleaned throroughly with contact cleaner before installing the new capacitors; - the PCB needs to be checked for open traces and repaired accordingly; it's a single layer PCB so repair is easy; - rotating parts of the mechanism should be cleaned and re-lubed (I recommend watch oil); - motor top bearing should be oiled; - belts need to be replaced; the secondary belt needs the takeup reel assy to be removed completely, so it's pretty involved; - leaf switches (there are 2), volume potentiometer, EQ and Dolby switches will all need to be cleaned with contact cleaner; - tape speed and azimuth will need to be checked and re-adjusted if necessary; Capacitor values: 220uF@4V (5pcs), 100uF@4V (1pcs), 47uF@4V (6pcs), 33uF@4V (2pcs), 22uF@6.3V (2pcs), 10uF@6.3V (1pcs), 4.7uF@25V (1pcs), 2.2uF@25V (1pcs), 0.47uF@50V (1pcs), o.33uF@50V (1pcs); Capstan belt: 50mm x 1mm (inner diameter x thickness) Secondary belt: 26mm x 1.2mm (inner diameter x thickness)
SONY WM-55/WM-R55/WM-F77 Most of the repairs are related to the mechanism, on the electronics side only common problem being the headphone jack which needs to be glued and re-enforced. It will obviously need a new belt, which can be purchased from FixYourAudio. Repair and maintenance items: - headphone jack is likely to need repair. This is achived by glueing and re-enforcing with electrical tape, then adding another layer of glue over the tape and finally glueing the jack to the PCB. - volume potentiometer and Dolby/EQ switches will need cleaning with contact cleaner; - pinch rollers will need to be replaced in most cases; - the idler tire will need to be replaced, it's the main problem of this mechanism causing it to loop continuously between FWD and REV; Idler is available here: https://fixyouraudio.com/product/idler-tire-for-sony-wm-55-walkman/ - a general cleaning and re-lubrication of the mechanism is highly recommended on this unit; - Dolby levels may need to be adjusted for proper Dolby decoding; Pinch rollers: TPS-L2 type Dolby adjustments: WM-55/R66 - 44mV RMS (no load) at indicated test points (see service manual) with 200nWb/m ANSI test tape. WM-F77 - 100mV RMS (no load) at indicated test points (see service manual) with 200nWb/m ANSI test tape.
Sanyo JJ-P101/JJ-P100/JJ-P4/MR-02 The JJ-P101 is a full logic version of the JJ-P4/MR-02 mechanism, but both types of mechanisms share the same problems. Belt for the unit can be found at FixYourAudio. Repair and maintenance items: - supply reel has a magnetic ring that tends to detach from the table reel. It needs to be re-glued (use liquid type super glue). Typical symptom of this magnetic ring being detached is unit will continuously loop between FWD and REV because the hall sensor cannot detect reel rotation. - the 2 gears that drive the table reels on PLAY tend to break (they're from a rubbery material, not POM). There are 2 potential solutions to this problems: either you swap the FF/REW gears with PLAY and give up on FF/REW functionality or get a donor unit and have 4 POM gears. - potential problem with pinch rollers misalignment causing azimuth problems and/or eating tapes; Solution for this problem is to remove the carriage assembly and bend the holding pin back to the correct position. Friction points also need re-lubrication. - a general cleaning and re-lubrication of the mechanism is recommended; - volume potentiometer and Dolby/EQ switches will need cleaning with contact cleaner; Note these mechanisms work best with a thicker 0.8mm belt, since the thinner 0.6mm ones are too elastic and after some time of storage they will slip when engaging the camgear. Belt: 46mm x 0.8mm (inner diameter x thickness)
