Yamaha CR800 Transistor Replacement

[jandajr]

A BIC Beam Box.
One of my concerns is why the tuning meter goes almost full tilt, when I hit the on switch.
No matter the setting on the FUNCTION switch.
When tuning a station the signal meter on some stations goes to 80 for a couple of seconds then go back to zero.

 

[jandajr]

.

 

[jandajr]

A BIC Beam Box.
One of my concerns is why the tuning meter goes almost full tilt, when I hit the on switch.
No matter the setting on the FUNCTION switch.
When tuning a station the signal meter on some stations goes to 80 for a couple of seconds then go back to zero.

 

[jandajr]

I need to clear up something I posted earlier.
The tuner had no power before I replaced the FR to a one watt.
After replacing the FR everything ran perfectly for the rest of the day.
Now:
Tuning meter goes almost full tilt, when I hit the ON switch.
No matter the setting on the FUNCTION switch.
When tuning a station the signal meter on some stations goes to 80 for a couple of seconds then go back to zero.
No AFT or Stereo lights

 

[jandajr]

To make things easier I'm going to post a new thread.

 

[petehall347]

does am work ok ?

 

[avionic]

The switch is whisper quiet in all functions.
Worked flawlessly.
AUX, PHONO, AM settings work.

 

[petehall347]

if i was to take a wild guess i might choose tr18 in the tuner circuit .

 

[jandajr]

does am work ok ?

Yes the AM works

 

[jandajr]

Resolved all the issues, and my 800 is finally up and running. Replacing all the bad lamps did rid that popping sound in the speakers. Who would of thought!
Now it's time to complete the restoration. I have two new 6800uf filter caps to drop in, and now I want to rebuild the EQ sheet and preamp board.
My concern is about all the tantalum capacitors. I hear that they could cause serious problems and hurt the tone in preamps. What is the best capacitors to use as a replacement
for those little blue and orange meanies?

 

[petehall347]

what caused the problems ?

 

[jandajr]

The two 220ohm fusibles on the preamp were way, way out of range. After I replaced them, the problem was gone.

 

[avionic]

What is the best capacitors to use as a replacement
for those little blue and orange meanies?

Nichicon "pw"

 

[mhjmhjones]

I have a question about Yamaha transistor replacement: can you just pull out the transistors and insert new ones? If not, how do I actually get the old ones out and the new ones in? Solder gun? I can't see how to actually get in there!

 

[OMGCat!]

Soldering iron. A soldering gun will probably be way too hot and damage the board, traces and the component your trying to replace.
Most times it's not just transistors that go bad by themselves. I'd post up a new thread about your issues.

 

[avionic]

I have a question about Yamaha transistor replacement: can you just pull out the transistors and insert new ones? If not, how do I actually get the old ones out and the new ones in? Solder gun? I can't see how to actually get in there!

What transistors are you referring to ? There is probably 50-60 in there.

 

[avionic]

Replacing all the bad lamps did rid that popping sound in the speakers. Who would of thought!

I could have told you that.