Project One MARK IV B - FM Muting question?

[jpreza]

Good afternoon everyone,

I finally brought back to life a Project/One MARK IV B Receiver that I bought last year. The original owner had disclosed that the R channel appeared to be going out. I worked on it for a while and after not able to figure out what was wrong I set it aside for a few months. I brought it back out a couple of weeks ago and after reviewing that the C1400 are noisy transistors, I replaced them and the unit is back to life!!

I recapped the Tuner/AF, Power Amp, EQ/Phono Amp. I still have the power supply board left - it's got a bunch of 220uF/470uF caps + two 10000uF caps. which I'll be doing soon.

Having said that, there are a few minor issues I need to address:

1. Both power meters are out
2. The strength meter is somewhat working
3. FM muting is NOT working

For #3, I traced back the two wires that are connected to the FM muting switch, which of course go to the Tuner/AF board. I went ahead and retouched the old/cold solder points just to make sure but this still did not fix the issue. There is no service manual available anywhere so I'm wondering if anyone has any experience with this receiver that may be able to guide me.

TIA....JP

 

[Oerets]

The Project One in that series seem to all have issues with the meters sticking, locking needing a tap to free. Or just plain go open. Also an issue I have run into are the flip switches are of a bad design causing the contacts to get loose or wobble IIRC.

 

[jpreza]

The Project One in that series seem to all have issues with the meters sticking, locking needing a tap to free. Or just plain go open. Also an issue I have run into are the flip switches are of a bad design causing the contacts to get loose or wobble IIRC.

I should've added that I did tap the power meters many times and that didn't work. I eventually did crack them open trying to get the indicator needles free but that still didn't work.