I recently scored a mint condition 701C complete with box and accessories sold as non working. After changing belt and pinch rollers (both had intendentions after being left engaged) it is working great when playing forward, however playing reverse side of tape has less treble. What can be the cause of this? It is not a showstopper for me, more curious if there is anything to do about it.
The first suspect in such a situation is a misaligned azimuth. Given azimuth is not adjustable on these units, I would start by checking if there is any tape curling near the pinch rollers. Take the door off and run a cassette with door off, then observe from above. A cassette with transparent shell will be the best for this. Also check the head position visually, if it's visibly tilted to one side. If the problem is in the electronics, only potential suspect is the head preamp IC which also contains the electronic switches. Anything else wrong would cause less treble on both sides, not just one.
Thanks for your tips. I have checked the playback to see how the tape behaves and it looks good. I also rechecked the pinch roller and noticed some uneven plastic on top, I fixed that but I don't think that it had any effect on playback. I did notice however that the head is tilted to one side no matter which direction the playback goes. Also I have noticed that the cassette sits in a quite strong grip when inserted. Once inserted it doesn't feel it is a tight grip, it can move around freely. When taking out the tape there is again required some minor force, it looks like it is because the tape has to be a little in angle to get it out so maybe this is normal? When listening a little more it sounds like the tape is not moving stable over the head, treble can be quite good just after starting playback then fade. If I shake the player slightly treble will improve for a second or two.
Ok, so let me undertand: the head is tilted when looking from above ? In stop mode it's normal, as it's not engaged, but in play it should be more or less straight. If cassette has play in the carriage, there are some metal springs that may need to be bent a bit more to keep it firm into place. Put some pictures with how the cassette fits, as I don't remember out of my head how the carriage is built on this particular model.
I hope this helps.... and of a wm702 but it should be the same ... the azimuth is given by the pin that comes out under the head ... and runs inside the brown mechanism
@Rune Lindman I think what happens there is the head is not fully engaging on that pin, judging by how it looks on the pictures. Or maybe sometimes it engages, sometimes not. Potentially a lubrication problem.
Yes, I think you're onto something here. I was thinking the same as I can se the mechanism inside moving when engaging play but head is not. I will look into why it's not moving.
Indeed that was the issue, after some lubrication the head is now moving forward when play is engaged. It still has a problem with the last 1/10mm when engaging, it is tilting the head slightly. A light tap on the player makes the head fully engage and it plays perfect on both sides. Maybe I need to fulle disassemble the head from the mechanism and clean out old lubrication?
Many thanks Valentin and Silver965 for your help and detailed pictures. It is really enjoyable to try to rescue as many as possible of these old gems.
Check if that pin moves freely, maybe you need to clean and re-lube the pin as well. You are clearly on the right path.
@Rune Lindman a difference that I notice from your photos to mine, that on the 701 there are no such references for the cassette
There is one on the 701C, it's kind of a rounded square thing, you see it on one of my pictures. It looks like they improved upon this in the 702.
Hi On The Beach, I'm using something called G-Lube, product made for gamers: https://www.gloriousgaming.com/products/glorious-lube-g-lube I'm sure there are better alternatives but it was I had at home and it has been working fine for my projects. This didn't fully adress the issue. I will disassemble the complete head mechanism and see if there are any old grease that needs to be removed. This will need to wait until after vacation though.
Update: The situation has improved quite a lot by a simple an obvious measure, cleaning oxidation from the battery terminals. Now it engages correctly 9/10 times. It seems it did not have enough power before. Feel a little embarrassed not doing this before but I inspected the terminals when I bought it and they looked fine, no battery leakage. I discovered this by noticing the battery were not fully discharged after the 701 stopped, the battery could work for quite awhile in another walkman after that. My feeling is that the last 1/10 time it doesn't engage fully without a gentle tap is because of dirt or old lubrication onside. I haven't fully disassembled it and cleaned it as I thought the problem was with the head and tape path. Hopefully this information can be useful for someone else with this wonderful and great sounding Walkman.
