cr-440 powers up... no sound

rmunson

Well-Known Member
Hi Everyone -
I'm having a problem with my yamaha cr-440 -- hoping it's not major --

I power up the receiver, everything lights up, powers up ect -- tuner seems to be pulling signal...

but...

no sound

I haven't tested the phones jack... but no sound from both pair of speaker outs.

I opened the case and looked at the 3 fuses and they appear to be ok -- I didn't take them out I just looked to see if they were blackened or blown -- they appeared ok.

Any ideas?

Thanks in advance,
Reed in Lakeville, MN
 
Hi, easy stuff first then the intelligentia can chime in.

- are all controls in the proper position?, speaker switches, tape mon etc.
- do you hear a relay click shortly after turning on?
- check fuses with a flashlight, they generally don't burn out and change colour but rather the hair thin wire inside gets a break in it, difficult to see.

Try to get some headphones on there and see it they work.

-Dave
 
ok -- will check those things --

will not try to fix relay myself this time :)

is it ok to remove the fuses for inspection?
 
rmunson said:
ok -- will check those things --

will not try to fix relay myself this time :)

is it ok to remove the fuses for inspection?

Just listen for the click, say 3 to 15 seconds after flipping the power switch, no need to dig in at this point.

Yes removing the fuses is fine, don't mix them up, they may have different values.

(ron-c, I didn't mean to imply that you are not one of the intelligent ones, you just posted a little quicker than I)

- Dave
 
Use an ohm-meter with a probe on either end of a given fuse to make sure that the fuse is still good. Sometimes, visually it looks OK, but it really isn't. With my Yamaha B-2 amp (after it was delivered) the fuses looked fine, but no output (and click of the relay). Checked ALL of the fuses and found one partially damaged. Replaced the fuse, click went the relay and we had output!

Try the simple and not-so-obvious first, before fearing the worst.

Also, it could be that the switches are dirty and need some DeoxIT. I've had more trouble with dirty input selector switches bollixing-up output.


...and as Lt. Columbo used to say...one more thing...see if there is an "Adaptor" switch on the front panel (couln't find a CR-440 manual at the Yamaha site, but there is a CR-840 manual). If there is an "Adaptor" switch on the front panel (for a Dolby Unit or Equalizer), make sure that it's turned OFF. If it's on, then no output unless an external Dolby unit or equalizer are attached). I don't think that there are any Pre-in Main-out connectors/switches on the back panel of this receiver.
 
I'm not getting any ping on turning the receiver on -- as I recall I previously did get a ping from the protection circuit when turning the receiver on and off --

with the ohm-meter test -- do I just put the probe on the fuse and set it to the amp the fuse is 2.0 and 3.5 and test to see I'm getting 2.0 or 3.5? I've never used an ohm meter before <---- newbie
 
One probe on each metal end of the fuse, you can leave them in the receiver but make sure and double check that it is not plugged in when you do this.

You are looking for "0" on the meter or continuity or no resistance which means that the fuse is good.

You could probably wing it with a flashlight battery and a bulb, not the best but will give you an idea.

- Dave
 
Hey - thanks for the tip -- I set the meter to RX 1 and get a reading half way between 0 and 1 -- does that mean that the fuse is ok?

this receiver has 3 fuses and they all read that way -- half way between 0 and 1
 
wajobu said:
Also, it could be that the switches are dirty and need some DeoxIT. I've had more trouble with dirty input selector switches bollixing-up output.

...and as Lt. Columbo used to say...one more thing...see if there is an "Adaptor" switch on the front panel (couln't find a CR-440 manual at the Yamaha site, but there is a CR-840 manual). If there is an "Adaptor" switch on the front panel (for a Dolby Unit or Equalizer), make sure that it's turned OFF. If it's on, then no output unless an external Dolby unit or equalizer are attached). I don't think that there are any Pre-in Main-out connectors/switches on the back panel of this receiver.
No "Adaptor" switch on the 440, I'm pretty sure the CR-840 was the lowest number of that series to have it.

And a good round of DeOxit Faderlube would be good, whether that's the problem or not.
 
rmunson said:
Hey - thanks for the tip -- I set the meter to RX 1 and get a reading half way between 0 and 1 -- does that mean that the fuse is ok?

this receiver has 3 fuses and they all read that way -- half way between 0 and 1

Sounds like the fuses are good. Switch and pot cleaning is an excellent suggestion though I would expect to hear the relay click regardless of dirty switches.

I halfway suspect that the relay may be stuck or something leading to it has gone bad, a diode maybe but that kind of thing is way beyond my level.

If it was me (and I ain't no bright boy) I would fire it up and lightly tap the cover of the relay with the plastic handle of a screwdriver to see if anything happens. Be forewarned that this can be risky if you are not familiar with the internals and is really a pretty hacky way to diagnose.

Really the smartest thing would be to call out to Merrylander, he would know the most likely failure to look for.

- Dave
 
Hey Guys-
an update on my CR-440 that quit making music - it lights up, meters move, fm tuner lamp lights -- no sound.

The other night I took it off the shelf and connected it to another receiver using the tape out (from the Yamaha) to rec in (on the Pioneer). To my joy I got sound! :banana:

I'm able to switch between inputs on the yamaha and hear them on the pioneer.

So it looks like I have a functional preamp section on the yamaha but the main amp is blown.

Is there anything obvious that I should look for in the power amp section?
 
Not so fast, Reed!

The fact that you get sound from the tape OUT jack means nothing. Tape OUT is almost always way before the tone controls, volume control, balance control and filters.

In short, it's a very short signal path from the souce to tape OUT.

Does the Yamaha have a Pre-OUT or Adaptor out set of jacks?

If not, then you really need to have someone determine where your signal is lost. When both channels are out, it's got to be something common to both like a regulated power supply, or speaker protection relays.

Hope this helps ...

Regards,
Jerry
 
I'm I the only one that thinks that cabinet (that was converted) on Reed's website was really cool before dismantling? Very cool (Eames or Knoll maybe), would have looked great in my living room. Surprised he didn't take it over to one of the retro shops in the twin cities, bet he could have gotten a couple hundred for it.
 
You may have to remove the bottom plate to check this. Set yout meter to DC volts, range 100 volts and with the power on check betwwen the chassis and pin 7 of each of the big power amp modules. If you read anything higher than 2 volts the power amp module is toast. Nearest replacement is STK0040 II

Rob
 
I've been having problems with my CR-440 also. After being on for about 1 hour the left channel would start screaching at full volume. None of the controls had any effect. All I could do was turn the unit off. When I disconnected the left speaker and turned it back on the right channel worked fine. I checked voltages on the power amp IC for the left channel and they were different from the right. During a retest the probe shorted out pins 6 and 7 and now neither side works. The speaker relay doesn't even come on. I assume both amps are now gone. I looked up the specs for the STK0040 II. Physically the package for the STK0100 matches what is in the unit but of course it's a 100 watt amp. Any chance I could use this one in place of the 0040 without having to make any other changes?
 
I also have a dead CR440 with this chip that is dead.
Can I put in a 0050 chip in place of the 0040 - and the original is yamaha IG02990.
How does it compare to the 0040.
Cool.
Srinath.
 
The whole series STK0040 II STK0050 II up to STK 0080 II and STK0100 II are electrically identical except for the voltage ratings, so yes you could use an SSTK0050 II but an STK0100 II would be overkill - try www.bdent.com or Audiolab Georgia.
 
Thanks.

Thanks, that gives a better chance of finding it @ the local electro/computer parts place.
Its not an stk0050 now is it. Its stk0050II - they are different aren't they ... cos I have the 0050 from my pioneer 790 repair adventure.
Cool.
Srinath.
 
OK this is strange.
stk0040 and stk0050 cross into a NTE1281. That's from the NTE site. STK0040 II is not found on it.
Now they have a stk0040K and a stk0040VT.
What is the stk0040II ? anyone know.
Cos I have the NTE1281 sitting right here. Its a 2 min swap in if it will work. Thanks.
Cool.
Srinath.
 
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