Discussion in 'Yamaha' started by maclvrbr, Sep 22, 2017.
IN pin/wire Right channel, RED wire, Left channel WHITE wire
Thank you sir. Does anyone know how to access this switch for cleaning? Thanks for all of the help.
coupler switch off main ins to in pin of R&L channels .3ohms
coupler switch on pre out to in pins R& L channel are OL on meter.
Wait on cleaning the coupler switch for a moment. I think I got the test wrong,maybe...
Maybe a typo in the SM, it shows a connection between PRE and MAIN
when the coupler switch is OFF and no connection when the switch
is ON, counter to the owners manual and the CA-1000.
Connecting a separate PRE "should" have worked unless we are talking
about multiple faults, maybe confirm this config through headphones.
Suggest waiting for others with direct CR1000 knowledge to chime in.
Refer to page 22 of SM.
Remove 4 screws on back plate
Remove 2 screws on side and loosen 2 screws then pivot backplate down.
Almost certain that was a typo in the SM.
Update guys when a source was plugged in main in inputs I have sound in both channels , I assume issue is in preamp section. Ideas and thanks
Would be nice to test using CR1000 as pre to external power amp. The coupler switch can be tricky.
Assume you don't have an oscilloscope.
The CR has problematic switches, both channels affected would normally mean power supply.
Have you tried with different inputs(=different switch positions) ie, AUX1,2, TAPE?
Will try and get some test points.
I have not worked on a CR-1000, everything looks so crammed/inaccessable.
You could try a basic continuity check to rule out some of the switches.
Amp powered off/unplugged.
Input selector set to AUX-2, all other controls normal position, SOURCE etc...
Measure resistance from Left AUX-2 RCA (inside) to wires on volume pot in brown rap.
One should give OL (right channel) the other should not give OL, maybe kohms
depending on switch position. You can try same for Right AUX-2 RCA.
Can also try connecting source(CD-P?) to TAPE-PB-A and tape
monitor switch to PLAY A, this would bypass the input selector. Any audio?
The tone and filter amp use +B(50V) supply
The filter amp has a mute function (TR607,8).
Try measuring the dc voltage at the green wire on the power board as shown.
Near zero volts is good.
Correction, need a high voltage to close the gate/break connection to GND.
Near zero volts is bad.
Can you just run a set of RCAs from pre out to main in and eliminate the coupler once and for all?
I had an R300 that had absolutely 0 sound from both channels and it turned out to be a (very) dirty input selector. After some Deoxit and a whole lot of turning back and forth it started to work fine. From the sounds of it you are dealing with 1 or more really dirty switches or pots.
thanks I have removed the switch and cleaned it as well as used a patch cord to connect main in to preouts still no sound. That would have been great if that switch was dirty. At the volume pot I used the finger test with headphones and got a buzz from both channels and assume signal is clean from volume pot to amplifier boards. I am trying to focus signal loss between volume pot and inputs ( I am using aux -1). I need assistance finding exact locations of signal through the remaining sections tape monitor switch board , function switch board etc. Without a scope I have been using a signal input ( home made) rca connector with ground clipped to chassis and lead alligator clipped to touch signal points on boards, I am playing a cd through the rca cord and touched leads to the volume pot producing R and L channel signals.. I know this is not typical but can I get some guidance to find signal path. I have cleaned these switch many times and suspicious of the function board PCB with all of the components it has as being a higher possibility of signal loss. thanks
If you've got a spare amp around you can make a signal tracer and work your way down the line from the inputs to wherever the music stops.
I use a landfill bound set of computer speakers I cut the 3.5mm jack off of. Clip the ground to chassis and solder a .1uF cap on either R or L input and use it as a test probe. Then you can see exactly where the problem lies.
Have you checked your power supplies that supply power to the flat amps and/or EQ amps ?
Check the fusible resistors within these circuits.
Audio path from AUX-1
RCA's to function board/Input selector
Violet wrapped wires
From function to tape monitor switch board
Green Wrapped wires (pins 14 and 17 on tape mon switch board).
Note TR911, 912 mute function
Tape monitoring switch to mode switch
Orange wrap wires (pin 1 & 3 on tape monitoring switch board)
Mode switch to loudness board
white wrapped wires (pins RO&LO on mode switch board, pins ri & li on loudness board)
Loudness board to volume pot
Red wrapped wires (pins RO&LO loudness board, pins 3 and 3' at volume pot)
Will check voltages on those amps boards thanks
Filter amp and equalizer amps and tone control amps.
have 50 volts at pcb boards did not see a flat amp board.
Any ideas for cleaning these switches ( sliders) some are almost non accessible. Thanks
Disassemble front panel. Remove switch from circuit board. Disassemble switches. Clean contacts. Reassemble switches. Reinstall on the circuit board. Reassemble front panel. Have fun.. There are no short cuts in my book.
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