This thread will cover the repair procedure for the clutch in the CX-5, CX-7, CX-F5, CX-F7, CX-R7 and CX-V9 walkmans. They all share the same mechanism, the R7 being a slight variation with the recording function, but mostly identical to the others. These mechanisms suffer from 3 main problems (all of which must be fixed): - a broken clutch (both the outer pulley and the drive gear break); - a loose belt (I recommend the DeckTech one); - a squeeling motor (it will need lubrication, especially on the bottom bearing); On the CX-R7, fixing these mechanical issues is enough as capacitors are not leaky. Speed adjustments can be done from the outside if necessary while Dolby levels are not adjustable (this is the case on all models). On the other models however, SMD electrolytics are to be found leaky and those will also need replacement. The CX-V9 uses the same mechanism as CX-R7 minus the recording part, however given I have not repaired one I cannot say if there are other problems in regard to the electronics side or not. NOTE1: I will not go into the details of how to disassemble these devices as there is enough information in the service manuals found on Peter Vis's website. I also assume that if you want to attempt such repair (which is complex) you already have the skills to figure out some steps on your own. If not, I recommend not attempting such repair, as even replacing just the belt requires a complete disassembly and the belt alone won't fix it ! NOTE2: Pay careful attention when removing the clutch from the chassis as the small white gear is likely to fly out under the action of the spring when you removing the cut washer ! NOTE3: Lubrication should be done only on the nylon washers: on top of the bottom washer (assembly 2) and on top of the second washer. I recommend using grease and put just a tiny amount and only on the surfaces that should slip. The spring should NOT slip on the top washer, rather the washer should slip on the white gear. NOTE4: It may be necessary to sand the bottom part of the white gear against a flat surface, as the washer that goes underneath must sit parallel to the bottom plate. Otherwise, some periodic click may be heard as the spring catches on the washer. PULLEY REPAIR: 1. Clean the black outer pulley well with IPA and clean your hands with soap to avoid any contamination with oil from your skin. 2. Add gel-type super glue in the broken areas of the pulley (I used Loctite brand) until the gaps are completely filled. It's not a problem if there is excess glue as it will be sanded at the next step. Let it dry completely. 3. Using an 800 grit folded sandpaper sand all the excess glue until the pulley's groove comes back to original shape. The outer layer must also be sanded, especially the botton part, as the clearance between it and the mechanism chasiss is very small. 4. Using a 2000 grit folded sandpaper, add a finishing touch to the groove until you can no longer feel any non-uniformities as you drag the paper along. GEAR REPAIR: 1. Clean all the parts with IPA; 2. Sand the middle shaft with 800 grit sandpaper to compensate for the shrinked white gear; 3. Install the 2 washers onto the middle shaft; 4. Install the middle shaft onto the clutch assy; 5. Install the brass plate; Pay very careful attention to install it with the recess facing down, otherwise, the clutch will turn very hard resulting in very high takeup torque, slipping the tape past the pinch roller; 6. Clean the visible part of the shaft and the inside of the white pulley thoroughly with IPA; 7. Install the spring and the washer above it as shown in picture; 8. Compress the spring with a pair of tweezers, while adding a small drop of liquid super glue on top of the middle shaft; 9. Install the white gear. Pay close attention to push it all the way in, as otherwise the clutch will not fit into the chassis; 10. Use some kind of clamping tool to hold the white gear until the glue cures. Put the clamp tool in a position as to compress the break line of the gear. Do note that in the assembly 4 picture the bottom plate is NOT installed correctly ! But for the time being I do not have another picture. Before comitting to re-assemblying the device, rotate the clutch by hand and if you feel or hear any abnormality (clicking or harshness) check it again before assemblying as any imperfection in the friction mechanism will make very audible mechanical noise and will ruin the wow&flutter.
