Hello, this is my first topic here. I have a AIWA HS-RX705. The belt is still there but it makes humming noises so I opened it. I will buy a new belt. The caps are leaking. Are those SMD Caps without the plastic bottom-part? Because they look different to the common hole-through ones. I already found the "list of common used caps-thread" so I will be able to search the right one. I need a different tip for my soldering iron. I am used to bigger caps because normally I restore turntables. There it is possible to use my desoldering iron. I think, this is to big on this circuit board. I think I have to use desoldering braid ??? What do you suggest? The next problem is the connection in the phones jack (is this the right term?).The plug only has connection when I hold it in a exact position. When I move just a very little, the sound is bad or just on one side. This is the case with the original AIWA headphones and with different ones. I saw the leaking caps that are next to the connection of the phones jack. Maybe there is a bad solder joint? Or something in the jack? Do you have a any ideas? Thanks for your help. Flo
Hello and welcome to the forum Boiled_frog ! The capacitors don't have the plastic bottom part because they are not SMD. Look on the other side of the board and you can see the solder points and even the capacitor symbol with polarity. Given than, you can replace them with normal electrolytics, as long as they fit. You can use a normal solering iron (with a fine tip) for replacing them. Here is a list of common walkman capacitors: http://stereo2go.com/forums/threads/list-of-common-walkman-capacitors-2017.1246/ It is to be noted that they're not available at all distributors, you may need to order from DigiKey, Mouser or Farnell (some stocks come from US with high shipping costs). TME, which has the lowest shipping costs in Europe does not have any of the capacitors you need (the smallest one they have is 220uF/6.3V and 100uF/6.3V, which will not fit on your board for sure). Regarding the headphone jack, I would clean it first with a cotton swab immersed in contact cleaner. Is the humming noise mechanical or in the headphones ?
Thanks for your reply, Valentin. I already saw this list and recognized, that it's hard to find these caps in Europe. Think I have to order from digikey. I will try to clean the headphone jack the way you suggested. The humming noise is machanical. Flo
From what I can see in the pictures, it seems like the walkman has a 3-phase brushless motor, typical of later designs that were very slim. This kind of motor sounds different than a typical DC motor with brushes. But if the humming noise is loud and can be heard from distance it is clearly a problem. What I would personally do in this case is lubricate the 2 capstan bearings, the shaft of the white pulley in the center and also the motor shaft. I think the motor rotor can be lifted from the stator and you can put oil on the bearing. This tutorial might be useful, although the motor is not the same, but it's of the same type: https://fixyouraudio.com/tutorials/panasonic-rq-s-series-walkmans-repair-guide/ Good luck with the repair !
