What to do with a broken Yamaha CR-1040?

Artie

Super Member
Hi folks. Wanted to get your thoughts/ideas on what to do with my old Yamaha CR-1040 reciever. Its in excellent condition, but the output modules are blown and Yamaha doesn't supply them any longer. I imagine they're basically STK modules but I don't have a cross reference.

This unit seems too nice to trash, but then again, is worthless as it sits. What would you do with it?

Btw - I'm an electronics tech with over 35 years experience . . . but I still need parts. :worried:

Thanks all.
Artie
 
Like you I have been there too many times and continue to be there even now. Who knows maybe one day you will find the right parts at the right price. Have you tried Consilodated Electronics, Inc and spoken with Steve he has been a life saver for me.
 
If it is not blowing fuses, use it for a tuner or if it has preamp outputs use it as a tuner/preamp and find a nice power amp. If a receiver is going to crap out I always prefer it be the power amp. If all else fails donate it to Merrylander and he'll hold it for parts for 1 of his treasures he tenderly retores and then sells at what must be a profit of -$1.00 but he makes it up in volume. I think is was actually desigining a module replacement for one of the STKs but maybe I'm wrong here.
 
I believe the output is STK0080II, which you can still get. It is the driver IC that is unobtanium.
 
Nakdoc has the part number right but rather than buy a couple of $18 STK modules first unsolder the old power amp modules. Then physically remove them so there is no chance of contact being made. Now power up the receiver and see if the relay clicks in, if so good. Next step, flip it over and locate the pre-driver modules (IG02930) and locate pins 13, 14 & 15 (pin 5 is not connected, so that will tell you how the numbering goes. Again power on, check pin 15, should be about 48V. Check pin 14, should be no higher than ~4 V, same for pin 13. If you see high voltages on pins 13 or 14 you have an elegant doorstop. I have figured out the internals of the pre-driver module but simply have not had an opportunity to build a couple of prototypes.

Rob
 
Thanks for the replies folks. Good info and ideas.

merrylander said:
Nakdoc has the part number right but rather than buy a couple of $18 STK modules first unsolder the old power amp modules. Then physically remove them so there is no chance of contact being made. Now power up the receiver and see if the relay clicks in, if so good. Next step, flip it over and locate the pre-driver modules (IG02930) and locate pins 13, 14 & 15 (pin 5 is not connected, so that will tell you how the numbering goes. Again power on, check pin 15, should be about 48V. Check pin 14, should be no higher than ~4 V, same for pin 13. If you see high voltages on pins 13 or 14 you have an elegant doorstop. I have figured out the internals of the pre-driver module but simply have not had an opportunity to build a couple of prototypes.

Rob

And especially thanks for that info. I have the modules out and I believe the relay clicks. (I'll verify in the morning.) I'll also check those voltages. If it looks good, I'll try the STK modules. If not, I may send it your way. :thmbsp:

Artie
 
I know this is an old thread, but i have a question.
Does the relay click if you have bad stk modules in?
If not, when you take the stk modules out and if the relay clicks, and the voltage is ok on pins 13,14 and 15 would new stk modules fix it?
 
I know this is an old thread, but i have a question.
Does the relay click if you have bad stk modules in?
If not, when you take the stk modules out and if the relay clicks, and the voltage is ok on pins 13,14 and 15 would new stk modules fix it?

Most likely.
 
Speaker relays will not click if DC voltager greater than about +- 1 volt is present on the output. A good test point is typically at an emitter resistor, but the better point is the RF coil in series with the output.
 
Doc is right, as the only adjustment on the 1040 amp is DC offset. So if it out of range it could cause the 1040 to stay in protect mode.
 
thanks for your input doc and merrylander.
i am just trying to decide if it is worth the time to drive 1hr 30 min to get a yamaha cr-1040 with no audio output(since the pre-power ic's aren't made anymore). It powers up and the tuner works. The guy is asking 10 bucks and since my dad has a honda that gets 40 mpg he might drive me to get it, but taking time to drive for 3 hrs is kinda hard.

What does anyone else think? Is it worth it to go get it?
 
I think it would be a nice electronic project to built a driver board for this receiver.

I have the schematic but it really needs a circuit board designed and etched. The basic circuit was an STK3040 but Yamaha added some circuitry to that and thus it was an OEM part. I have built one on a small Radio Shack perf board but it is a real PITA to do. Ideally if someone takes the circuit and converts all the components to surface mount you could almost duplicate the original.
 
Hello folks, I too have the same problem but fortunately picked up a donor unit that had a bad channel. I posted an query on the CanuckAudio forum a while back when I was looking for a parts unit and just this morning got a response from a fellow in California that has found a solution to his problem. I'll cut/past his post and also try to provide you the link on the CanuckAudio site. I hope this helps. My orginal unit is still on my bench waiting for a meter and a couple of lamps but this news may put some new life back into the donor unit for a comeback. Wouldn't that be fantastic. I would like to hear Rob's opinion on this though before attempting anything. Let's keep our fingers crossed. Best Regards......Joe

Here is the post...........

"Hi:

I think I may have come up with a replacement part for the unavailable IG 02930 driver used in Yamaha CR-1040 and probably CR-2040 receivers. My drivers went out as well. I found I can use STK-3062 or STK-3082 device as a replacement. Mine has been working for some months and no problems. here is the pin-out you need to follow.

STK-30xx pin 1 to IC-602 pin 1 (audio in)
pin 2 to IC-602 pin 3
pin 3 to 560 ohm resistor in series with 250 pf cap back to pin 4 of STK-30xx. This part of STK-30xx not used.
pin 5 to IC-602 pin 13 (audio drive to output device)
pin 6 to IC-602 pin 14 (audio drive to output device)
pin 7 to IC-602 pin 5 (power pin)
pin 8 to ground
pin 9 to IC-601 pin 15 (power pin)
pin 10 to IC-601 pin 14 (audio drive to output device)
pin 11 to IC-601 pin 13 (audio drive to output device)
pin 12 to 560 ohm resistor in series with 250 pf cap back to pin 13 of STK-30xx.
pin 14 to IC-601 pin 3
pin 15 to IC-601 pin 1 (audio in)

Before you power up the unit check voltage at unsoldered wires going to pins 5 and 6 (right channel) and unsoldered wires going to pins 10 and 11 (left channel) to the STK 30xx. If over a volt you probably have problems with the output device as well. Obviously rail +/- (10 to 39 V) present would blow the STK-30xx chip and you will need to start over with a new STK-30xx. I measure about 15 mv. on these wires to ground.

Hope this helps get some of these units back operating again.

Paul Warenycia/KA6NFP
Roseville, CA. 95661
 
OH holy cow, I am going to have to do this sometime soon. A DOA 1040 showed up @ my door.
This post will put this thread in my list of posts ...
Thanks.
Srinath.
 
Old topic, I know but I recently got a 1040 that works well. Just wondering if anyone knows a thread showing how best to add a heatsink to the STK modules that crap out as a precaution? TIA for any help.
 
Back
Top Bottom