Announcement

Collapse
No announcement yet.

Need help on Akai AT-S61 tuner

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Need help on Akai AT-S61 tuner

    I got the tuner free from someone. It seems that the tuner is not for my location (north America) because the AM starts from 522 kHz in step of 9 kHz.

    I have downloaded the Operator's manual and could not find any information on how to switch it to starting from 530 kHz in steps of 10 kHz which is for north America.

    I have also downloaded the Service Manual. I found that on P.15 (as attached), under the subject of "Operation" and "Key Matrix", there is information on this. But I am not sure exactly what should be done. Could someone please help by explaining in details what should be done?
    Attached Files
    Last edited by tmhobadcap; 10-02-2020, 03:12 PM.

    #2
    Re: Need help on Akai AT-S61 tuner

    The four diode possibilites set what band/steps the MCU will use.
    You need D25, D26 in and D24, D27 out for North America.
    It seems to have D24 in. So move that to D25 position and add a diode like 1N4148 for D26.

    Comment


      #3
      Re: Need help on Akai AT-S61 tuner

      Originally posted by redwire View Post
      The four diode possibilites set what band/steps the MCU will use.
      You need D25, D26 in and D24, D27 out for North America.
      It seems to have D24 in. So move that to D25 position and add a diode like 1N4148 for D26.
      Thanks for your reply but sorry, I do not understand what you mean.

      Comment


        #4
        Re: Need help on Akai AT-S61 tuner

        Originally posted by tmhobadcap View Post
        Thanks for your reply but sorry, I do not understand what you mean.
        What don't you understand? you need to REMOVE D24 & D27 and ADD D25 and D26 to the circuit Look at page 22 of the service manual for their location.
        So move D24 to D25 location and move D27 to D26 location
        Last edited by R_J; 10-02-2020, 07:34 PM.

        Comment


          #5
          Re: Need help on Akai AT-S61 tuner

          Originally posted by R_J View Post
          What don't you understand? you need to REMOVE D24 & D27 and ADD D25 and D26 to the circuit Look at page 22 of the service manual for their location.
          So move D24 to D25 location and move D27 to D26 location
          Thank you very much for your patient and further explanations.
          Why I did not understand was because I could not find all D24, D25, D26 and D27.
          At first, I only looked at the PC boards on P.21 because my tuner model no. is AT-S61. I only could find D25 and D26 at the bottom right corner of the PCB on P.21.
          After you mentioned P.22, then I also checked the PCB on P.22 and P.23 although they are not for my model. Then now I know D24 and D27 are also located at the bottom right corner of the PCB.
          Now based on P.21, 22 and 23, I marked where D24, D25, D26 and D27 should be on my actual PCB as shown on the below photos. If I am wrong, please tell me.
          If I am right, I will have some more questions. I can add diodes to location D25 and D26. But in the actual PCB, there are 4 diodes (in red circle area) and they not shown on P.21, P.22 or P.23. Should I remove them (the 4 diodes) and install just some connections as shown on P.21, P.22 or P.23?
          Also, I think we should follow P.21 instead of P.22 or P.23 because of the model no. and PCB no. Am I correct?
          What does Fig.10 on P.15 mean?


          Attached Files

          Comment


            #6
            Re: Need help on Akai AT-S61 tuner

            Those silver components are jumper wires not diodes, install 2 diodes, one at D25 and one at D26 positions and it should work. Any small signal diode should work, DS448, 1N4148 etc.
            Last edited by R_J; 10-03-2020, 07:47 PM.

            Comment


              #7
              Re: Need help on Akai AT-S61 tuner

              Originally posted by R_J View Post
              Those silver components are jumper wires not diodes, install 2 diodes, one at D25 and one at D26 positions and it should work. Any small signal diode should work, DS448, 1N4148 etc.
              Yes, you are correct. Those are jumper wires not diodes. That was my mistake.
              I used my diodes (PXPR1002) on hand for D25 and D26. The result was nothing shown on the screen/display. Even when I removed D25 and D26, I could not get back the screen/display. Did I damage the tuner because of the PXPR1002?

              Attached Files
              Last edited by tmhobadcap; 10-04-2020, 01:05 AM.

              Comment


                #8
                Re: Need help on Akai AT-S61 tuner

                Originally posted by tmhobadcap View Post
                Yes, you are correct. Those are jumper wires not diodes. That was my mistake.
                I used my diodes (PXPR1002) on hand for D25 and D26. The result was nothing shown on the screen/display. Even when I removed D25 and D26, I could not get back the screen/display. Did I damage the tuner because of the PXPR1002?

                I got it working now. There is no problem with using the PXPR1002 diodes.

                The main reason I got no screen/display was just because I was too lazy and did not pay attention to details. Thanks for petehall347 (from the other forum) reminding me that "maybe a wire off or loose plug". I did not take the whole PCB completely out for adding the diodes. The PCB has to be flipped while still with wires connections in a tight space. Therefore, I checked all the wires connections. The wire connections are okay. In the checking, I found that there are 3 points on the PCB are contacting to the chassis of the tuner (also via those 3 points to fix the PCB to the chassis with screws). With my limited knowledge, they should be the ground. But when I test the continuity among them, I found that one of them is not connected to the other 2. (They use the chassis to make all 3 points to be grounded). In my testing after installing the diodes, I was lazy that I just installed one of the 3 screws. Therefore, that point could not be grounded and so I got no display.

                Now I got the AM tuning correctly. Thank very much for all your effort guiding me through the whole process.

                Comment


                  #9
                  Re: Need help on Akai AT-S61 tuner

                  i am here also .. well done again .

                  Comment


                    #10
                    Re: Need help on Akai AT-S61 tuner

                    The AM is working perfectly now. But I need help again for the FM as well. I found that the FM cannot have stereo.

                    FM 103.5 is a strong radio channel in my area. When I tune to 103.5, the #4 SIGNAL STRENGTH INDICATORS with 5 leds all light up. When the #15 FM AUTO BUTTON is pressed (the #10 AUTO (FM MUTE) INDICATOR will lights up), I hear nothing. When #14 MONO BUTTON is pressed, the #10 will not light up, and I can hear the radio. And both conditions, the #5 TUNE INDICATOR and #6 STEREO INDICATOR will not light up.
                    But when I increase the frequency to 103.7 on FM AUTO, the #5 lights up, #6 flashes, #4 with only 4 leds light up, and I can hear the radio with a lot of noise. When I further increase the frequency to 103.8, I can hear nothing and #5 and #6 become off again.

                    Could someone please help me on this?
                    Attached Files

                    Comment

                    Working...
                    X