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yamaha ct 800 service manual

C

craig hodges

New Member
Just got my hands on a ct 800 yamaha tuner. I read somewhere that a replacement bulb kit consists of
4 bulbs but upon checking i only counted 3. i each in the meters and one in the tuner dial not sure where
the 4th one is, as i cant find a link to a service manual and am hoping someone in ak land has a link for one.
while on this topic of my ct 800 my signal meter lights up but the needle does not move can these be repaired
or do i need a replacement meter, if so does someone have a working meter they,re willing to part with.
 
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Punker X said:
When counting bulbs are you counting the pointer?
Click to expand...

The "pointer light" is the only defect in my Yamaha T-2. Hasn't bothered me "much" since there is the "digital" indicator as well. I might be tempted to replace it if I knew where to get a replacement and I could get over the "what could possibly go wrong?" element of opening it up.
 
Think this image shows the dial pointer illuminated. Small grain of wheat bulb, That lights up the pointer that indicates what frequency you are tuned to.

56a6-DSC_8632-0-1-1200x800.JPG
 
Punker X said:
Think this image shows the dial pointer illuminated. Small grain of wheat bulb, That lights up the pointer that indicates what frequency you are tuned to.

56a6-DSC_8632-0-1-1200x800.JPG
Click to expand...
Punker X said:
Think this image shows the dial pointer illuminated. Small grain of wheat bulb, That lights up the pointer that indicates what frequency you are tuned to.

56a6-DSC_8632-0-1-1200x800.JPG
Click to expand...
Punker X said:
Think this image shows the dial pointer illuminated. Small grain of wheat bulb, That lights up the pointer that indicates what frequency you are tuned to.

56a6-DSC_8632-0-1-1200x800.JPG
Click to expand...
Yep that's the one I have to change so there's only 3 bulbs in the ct800. I suppose you don't know how to fix the signal meter in these as the needles not moving.
 
Hello

as i cant find a link to a service manual and am hoping someone in ak land has a link for one.
while on this topic of my ct 800 my signal meter lights up but the needle does not move can these be repaired
or do i need a replacement meter, if so does someone have a working meter they,re willing to part with.

I think that you don't know how work the " signal meter " on CT800 like many YAMAHA tuners and receivers , this is specific to YAMAHA tuners and receivers and is patented . This is called " signal Q " Q like quality and if the sound is really bad , your meter will confirm this by no indication of the meter . More the meter is closer to zero , more the quality is worse.
The quality of the sound is depending of quality of the reception
Replacing your meter is not usefull because it is probably not because of it, except if you have DC Voltage across it and no deflection . In this case the meter is bad
 
craig hodges said:
I suppose you don't know how to fix the signal meter in these as the needles not moving.
Click to expand...

Easy way to determine if your meter is bad or the circuits driving them is with a multimeter. Set to read ohms and put on the lowest ohm setting, On the Signal meter quickly touch the leads of the meter don't hold for a long time. The meter should move. With red on the positive terminal it will defect toward full scale, if backwards will drive it to zero. On the tuning meter, The pointer will move from center and the opposite way if your revers the meter leads.

If the meters movements are good, then the circuits driving them are the problem. Could be dirty switch contacts, alignment or a component failure. If the meter seem bad, Repairing them is delicate work. Sometime is a interference issue, sometime they just get stuck, sometimes there is a bad connection from the coil to the lead. And sometimes there is a failure or damage to the movement that is not repairable.
 
clinic-audio said:
Hello

as i cant find a link to a service manual and am hoping someone in ak land has a link for one.
while on this topic of my ct 800 my signal meter lights up but the needle does not move can these be repaired
or do i need a replacement meter, if so does someone have a working meter they,re willing to part with.

I think that you don't know how work the " signal meter " on CT800 like many YAMAHA tuners and receivers , this is specific to YAMAHA tuners and receivers and is patented . This is called " signal Q " Q like quality and if the sound is really bad , your meter will confirm this by no indication of the meter . More the meter is closer to zero , more the quality is worse.
The quality of the sound is depending of quality of the reception
Replacing your meter is not usefull because it is probably not because of it, except if you have DC Voltage across it and no deflection . In this case the meter is bad
Click to expand...
My reception is good sound is good and stations lock on I used a cheap ribbon antenna and it finds all the stations although it only plays it mono until I get a better antenna that's a coaxial to fix that problem and the meter still doesn't move so do you need a multi meter to check for dc voltage across it.
 
clinic-audio said:
Hello

as i cant find a link to a service manual and am hoping someone in ak land has a link for one.
while on this topic of my ct 800 my signal meter lights up but the needle does not move can these be repaired
or do i need a replacement meter, if so does someone have a working meter they,re willing to part with.

I think that you don't know how work the " signal meter " on CT800 like many YAMAHA tuners and receivers , this is specific to YAMAHA tuners and receivers and is patented . This is called " signal Q " Q like quality and if the sound is really bad , your meter will confirm this by no indication of the meter . More the meter is closer to zero , more the quality is worse.
The quality of the sound is depending of quality of the reception
Replacing your meter is not usefull because it is probably not because of it, except if you have DC Voltage across it and no deflection . In this case the meter is bad
Click to expand...
I fitted a cheap ribbon antenna picks up stations beautifully although not in stereo tuning meter is spot on but signal meter still won't budge so I'll get a multi and see what I can find.
 
Good Craig

Let us know if you get any DC Voltage accross it
If your meter is bad give us the part number marked on it
 
clinic-audio said:
Hello

as i cant find a link to a service manual and am hoping someone in ak land has a link for one.
while on this topic of my ct 800 my signal meter lights up but the needle does not move can these be repaired
or do i need a replacement meter, if so does someone have a working meter they,re willing to part with.

I think that you don't know how work the " signal meter " on CT800 like many YAMAHA tuners and receivers , this is specific to YAMAHA tuners and receivers and is patented . This is called " signal Q " Q like quality and if the sound is really bad , your meter will confirm this by no indication of the meter . More the meter is closer to zero , more the quality is worse.
The quality of the sound is depending of quality of the reception
Replacing your meter is not usefull because it is probably not because of it, except if you have DC Voltage across it and no deflection . In this case the meter is bad
Click to expand...
How do you tell if you have dc voltage a
clinic-audio said:
Good Craig

Let us know if you get any DC Voltage accross it
  • If your meter is bad give us the part number marked on it
Click to expand...
I won't get around to testing this until the week end so I'll reply with what I find and the part number I can get now JI 0002362BA
 
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