Fisher 200t weak FM signal

[Odizzieus]

I just picked up a fisher 200t today for $28 dollars at an estate sale. The phono input and aux both work, but when I switch to the FM input with an antenna connected, the signal is barely audible at full volume. The signal strength meter works, but the stereo light never shows, likely just because it needs to be changed. There is no loud static, and FM muting is off. I have cleaned all the potentiometers with contact cleaner, and the issue persists. Any help would be appreciated

Also, the signal is still quite regardless if I have the unit in stereo or mono

 

[Dave451]

All tubes lit? Can you check them (tube tester)?

 

[HTHMAN]

All tubes lit? Can you check them (tube tester)?

No tubes, it is solid state.

 

[Odizzieus]

I also want to clarify that when I say weak, I mean extremely quiet. The signal strength is strong according to the indicator. The actual audio can not be heard unless I turn the knob up to max

 

[Dave451]

Whoops, read it too fast--sorry! In that case, double check antenna connections. Other than that, you can go to HiFi Engine and pull the service manual and start checking voltages. Other owners may be able to point you to any known problems with the tuner. Your receiver may be mis-aligned (if someone has been messing around inside) or may have a front end/IF problem that will require service.

 

[Dave451]

Couple other thoughts: clean the FM muting switch with a light shot of contact cleaner and work it. Turn the receiver over and pull the bottom cover and look for the FM muting trimmer pot that is beside the meter adjustment trimmer. Hit it lightly with contact cleaner and work it a little (set it back to where it was) and see if this makes a difference. (The exact location of this control is shown on the chassis view in the service manual). Good luck with it!

 

[Odizzieus]

Couple other thoughts: clean the FM muting switch with a light shot of contact cleaner and work it. Turn the receiver over and pull the bottom cover and look for the FM muting trimmer pot that is beside the meter adjustment trimmer. Hit it lightly with contact cleaner and work it a little (set it back to where it was) and see if this makes a difference. (The exact location of this control is shown on the chassis view in the service manual). Good luck with it!

There is no fm mute adjust

 

[Dave451]

Sorry again, man. I'm also working on a 700T and had both schematics up and looked at the wrong one. Yep, the 200T just has a meter adjust pot underneath. I think I'll close down for the night and avoid misleading you further. Hit the FM mute switch with cleaner and see if that helps, if not you may have to go into troubleshooting mode on the front end. Also could be a problem with the "meter and muting" board, which mutes the FM audio signal and the 19 kHz pilot signal (which goes to the MPX stereo decoder and causes the "stereo beacon" lamp to light).

 

[HTHMAN]

I'm also working on a 700T

Just a question for you and I do not intend to hijack the thread. I have a 700T and everything works except the dial pointer light. As you know, it is integral to the pointer and to replace the light is to replace the pointer. I am afraid to try to transplant a wheat bulb in it for fear of breaking a non-replaceable part. Any suggestions?

 

[Dave451]

See below from the service manual on changing the pointer lamp. Looks like the who assembly needs to be changed and you'd either have to find one from a parts rig or try to open it and change the bulb, as you suggest.

Here's a link with a suggestion from Larry L, but no further followup: http://audiokarma.org/forums/index.php?threads/fisher-dial-pointer-lamp.380625/

Here's another link with some thinking on replacing the pointer: http://audiokarma.org/forums/index.php?threads/fisher-700t-restoration-begins.539307/page-2

I have not powered the 700T yet, as it has a sticker on the back saying the right channel is bad and I don't want to power it until I check the output transistors and drivers. I may start a thread on that, meantime this is the best I can find on that pointer lamp. Good luck!

 

[HTHMAN]

Yep, I was part of both posts, but neither has actually done it. Afraid to try to scoop it out for fear of breakage. Was hoping someone had actually repaired it.

 

[fred soop]

Go back to my 600-T restoration thread from 2014. I replaced the pointer lamp with an LED and changed the power feeding it accordingly. Will eventually be repeating that on another pointer and plan to have more photos. This was one of several features that set Fisher apart from competitors for appearance.