Designed to be the world's smallest walkman yet, the National RQ-J1 series (WJ1, KJ1, SJ1) exclusively used a flexible PCB with SMD components. This, in my opinion, made made this quite a daunting unit to work on, as its feels different than your usual stuff and quite flimsy. From experience, it's actually not as fragile as it seems. Since this is quite a rare model anyway, I though a peek inside would be quite interesting to share. And I hope that this guide would help those that was "scared-off" at first sight when opening it up, as I certainly was If you can judge a unit's build quality by number of screws, this one is certainly very high. 7+1 in total, and 4 screws on just one small side... Your first view of the innards of the walkman would be the flex PCB. There really is not much else to see, as it hides all of the mechanism. An advantage of the flex PCB is that you can do without wires everywhere. Quite a different look from the almost as small Sony WM-2. To connect the switches which are on a different level, a slit was simply made on the PCB that lets that part drop down. Note: There should be a shield panel on top, but this unit's missing that. Be careful not to bend the PCB, especially the parts that are already bent 90 degrees. Even the manufacturer printed a note of that. Like the early Sonys, this to uses a long cylindrical motor. But it's smaller than Sony's MNF-1600B. The original belt what the thicker type, not those thin ones that most (especially the smaller ones) need. When reassembling, just retrace your steps. It's quite a straightforward and easy process, not much to align, things fall quite neatly back in place. Just make sure screw holes fall on the right side of their respective brackets, and to insert the guideposts of the switches to the base. The plastic should be flush with the metal. That would insure that the leafs are in the right position. While you're at it, you might as well clean the contact points. My unit was previously not FF/Rew-ing because of a dirty pair of leaf-switches. P.S. In retrospect, I think I should've take more pics. Especially in the movement of the parts after unscrewing... Well, maybe next time.
excellent tutorial. thanks for sharing I have few of this model that need some restoration. This model is very weak on capacitors.
Ah, is that so? I have several as well, and one is not outputting any sound. As for the others, I noticed that there is 1-2 second delay between the pressing of pay and sound coming out. During the delay, the found fades in gradually. Perhaps they all need some recap?
yes, thats true I opened the walkman and found the capacitor leak in 2 of them (obvious) but those capacitors are SMD type and I do not have any experience about replacing them So for now I have to wait till i find a technician to do it for me.
