Sup team !! After getting the service manual for this beauty, here are some pics with the disassembled parts and stuff. Background: The unit has the battery cover in good shape and powers up with both batteries and external power supply. But, when using the external power supply, you can hear a high pitched squeal on the headphones. This does not happens with the batteries. The motor spins, but not the spools, nor the capstans. Radio works pretty good and with good signal strength, even indoors. Time to open it and change the belt, and see what other surprises it has: Taking out the main back cover reveals the first glimpse. ERROR #1: I should have taken the JACKS cover first (left of the pic), this will avoid damaging the back cover. So, this unit has already been serviced before, since the brown double side tape protections are not normal for a new unit. BTW this double sided tape is HORRIBLE, too sticky. The soldering points of the yellow flat cable (for the EQ) look good, but not factory quality ones. This is the jack cover, revealing a very efficient way of using the tuner dial. No strings attached (literally). Here is what this jack cover actually protects, the AM antenna, mic and headphones jack, and 2 switches. You will need to remove the screw holding a small metal plate below the gears, and another smaller screw just below left of the MIC jack (missing on this pic, you can see the hole. Previous guy forgot to put it back). Then, taking out the top cover, 2 small screws only, revealing the physical buttons, head connectors, direction indicator, 3 switches, 1 mechanical switch for the autoreverse selector and the open door switch. Now, you can lift the PCB, but first, you need to desolder the EQ yellow ribbon, desolder the positive terminal from the battery door and desolder the 5 soldering points that join the Main PCB with the Motor Board (marked in purple), unscrew 2 phillips screws on the main PCB (marked in Blue). Optional, you can remove the 2 small screws from the motor board, but it is not needed. Now you can lift the main PCB from the battery compartment up, do it gently and be careful of the cables coming from between the Main PCB and motor board on the bottom. You need to unplug a small white connector located on the RIGHT side of the PCB. This are the PLAY and Autoreverse sensor cables. Now you can access the back of the mechanical part. Here you can change the belt. Make sure to clean the belt path on the brass pulleys to ensure no goo or belt residues are left. Do the same with the motor pulley. In this pic, I did not desoldered the motor board, hence the cables from the motor and sensors are showing. And here a pic of the Main CB from the inside. Notice the black component near to the white connector on the left. This is C179, a Tantalum 100uF 4v capacitor that was blown. It should look like the one right on top of it, shiny blue. It was replaced afterwards, removing a lot the squeal sound when using external power supply. Once the cap and belt were replaced, time to get everything back to how it was before. Remember to reconect the white connector, resolder the yellow ribbon from the EQ, the motor board and the positive terminal from the battery compartment, put back the screws holding the Main PCB and the 2 screws from the jack connectors side (with its small metal plate). Before putting the back cover (the big one), you can check with a cassette the tape speed and adjust it as necessary. You need to turn the screws located on the Motor board, one for each play direction. Outcome: The unit is back alive. Radio still sounds great, but... cassette has a lot of wow and flutter. Recording is working as well. I have cleaned the head, rollers, capstans (outside and inside while changing the belt). The pinch rollers look pretty good, not glazed, cracked or deformed. Capstan shafts are straight and lubricated, belt is good with no visible vibrato (eveness of the belt, it does not moves sideways or up and down during transport). It needs more service after this one, but would like your input on what else might I need to check to ensure it plays as smooth as possible. Hope this helps, thank you all!
Round 2 of this restoration: I have not been able to fix the high wow and flutter that this unit is having, but I have noticed a new behaviour: When playing a tape in reverse, it sounds good, until about half of every tape I have played. It starts with a very soft and then increasingly noticeable "scratch" sound, up to a moment in which you hear the tape as it it had a lot of hiss on it. If I stop the tape, and resume play (just pushing stop then play), it sounds good again, but after a while, the scratch and hiss sound comes back. This happens only when playing any tape (I have tried normal and CrO2) in reverse mode (that is from left to right).
Replaced the belt on my HS J09 Now when I connect the battery it's stuck in forward or reverse mode! - Any ideas to what went wrong?!
Hi Darth Odious, By "stuck in forward or reverse mode", it means that, if you just plugin the battery, the unit behaves as if you were pushing the Play button, but without pushing it? It activates itself? Or, when playing a cassette, it just plays in one direction? It is very possible that, during reassembly, the sensors for play / ff / rew might got caught and they are in the wrong position. This sensors are normally a small pair of copper plates that make contact when you press a button. This sensors can be seen on the 7th pic of my original post. On the right, above the white cog, there is a switch. To the left and right there are 2 of this copper plate sensors. Please share us some more details.
Hi Darth Odious, This sensors are activated by a small metal plate located on the mechanical part of the unit. Regularly, this plate should be located on one side of the 2 metallic plates on the components side, so that, when activated, the metal plate on the mechanical side slides, it pushes both metallic plates on the componets side so they touch each other. It is very difficult to see and photograph, but on the other side of the components PCB (picture 1 on the post), there is a small hole where you can see the state of this metallic plates. This holes are made so you can assess the position and ensure that they are correct. But how to ensure they are correct? The "stand by" position, that is, without activating any button on the unit, should be both sensors open (the copper plates should not be touching). When you activate a button (normally play or FF/RW), the copper plates should touch. This action can be seen through the hole.
Thank you for your information. I have recently replaced the belt on my HS-J600. After replaced the belt, I could sometimes hear some noises in either forward or reverse direction. Changed the play direction could sometimes improved it. So I guessed it was the slide switch, and after I cleaned the slide switch, the noise is gone forever. I think this may fix your issue.
Many thanks for the information Phoenix Chan!!! Hope you enjoy your unit, it is a marvel of technology!
Hi, i have a Aiwa HS-J09. Have just replaced the belt on it, everything was working fine until i tried to record on it. Now the play button dont come all the way up, seem like it stuck halfway up.
I have one that does that sometimes. Frantically pushing buttons including pushing the Play button ALL the way down eventually allows the Stop button to release the Play button. You can then figure out a sequence to reliably release the Play button. I haven't figured out the problem. This one had bent metal parts in the mechanism. I straightened all I could find without taking the mechanism apart. It works well enough that I'm not going to try to find a donor unit with roached cosmetics and main board but good 2ME-7 mechanism. Since you mentioned an association with recording... There is a little lever with a spring near the battery compartment. This is part of the mechanism that prevents recording over commercial tapes. The lever can get stuck in place due to battery corrosion. And the spring is the easiest one to lose when working on these units. I put a speck of glue on the spring to ensure it doesn't go AWOL. In the bottom of the cassette bay there are two levers. Both should be movable and spring back to default positions.
