Yamaha CR-1020 popping/re-lamp/idle current/speakers

Greg Weed

Giant Sloar
Hi, everyone - my first post.

I have a new Yamaha CR-1020 receiver, and I just love it. It's beautiful and it sounds sooo great playing my BIC 920 turntable. Thanks to Merrylander, Avionic, Simplyidiot, and many others for all the info. I've been reading here for days.

I've done 3 days of Deoxit Red treatments on all the controls, including the coupler switch in back, and working the controls hundreds of times after each, greatly ameliorated a very weak left channel. Crayon on the tuner string fixed its grab. (see picture.)

I am getting very intermittent popping. Shortly after powering up, then it might go hours without popping at all. It put it into protection a couple of times, but to seems less severe after the last cleaning/working of the decoupler switch.

I've never worked on electronics before, but I'm ready to buy a voltmeter and test/adjust idle current. First, some newbie questions. My apologies if these are available in threads or stickies somewhere else. I've seen threads and I have the manual.

1. When testing/adjusting idle current, other than using a non-metallic screwdriver and not touching things, how do I keep myself and the unit safe?

2. When clipping the meter to TP0 to test idle current, where exactly do I clip it? On the solder?

3. The LEDs are working except for "FM Stereo." It did come on weakly for a while once, and one other time it came on to accompany a pop, then went back off. A clue?

4. Any advantage to using jumpers to bypass the pre-main coupling switch?

5. Lamps are all out. I'd love to re-lamp myself, but I've never used a solder gun. If I had a backup receiver, I might experiment, but I don't. I'm in Washington, DC, so I was crushed to see that my Maryland neighbor Merrylander no longer works on equipment! I'm two years too late. Any other recommendations for economical re-lamping in the DC area? I've also read that re-lamping sometimes clears up popping at shutdown, which I'm experiencing.

6. Speakers (don't laugh). I'm running either 4-ohm JBL Control 1s monitors or 6-ohm Pioneer SP BS-22s in series through an 80-watt Dayton Audio 800 subwoofer. The 1020 manual says not to run A AND B if anything's less than 8 ohm, so I'm not. But am I OK with this setup?

Thanks in advance for any replies. I've already learned a lot here!

Greg
 

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CR-1020 popping - relay switch

Sorry, I forgot to mention - I haven't messed with the protect relay switch at all. I might clean it - I am experimenting with making a cover shucker. -Greg
 
Welcome to AK..
2. When clipping the meter to TP0 to test idle current, where exactly do I clip it? On the solder?

TP O should have a PCB mounted solder lug fastened to it. Clip to the lug.Get a set of mini-grabbers for your new meter. These will minimize the chances of the meter test probe from shorting anything out should it slip off the test point.
 
When testing/adjusting idle current, other than using a non-metallic screwdriver and not touching things, how do I keep myself and the unit safe?
Mini-grabbers.
I am getting very intermittent popping. Shortly after powering up

This could be a number of things. From simply a cold solder connection to a bad component. Transistors are the usual suspects.It stabilizes once the unit warms up indicating a thermal issue. First place I'd look is the pass transistors on the power supply board. The two TO-220 transistors on the PS board are the "pass" transistors.<----- these usually have crusty dried up glue around the base of the little heatsinks that needs to be scraped away and cleaned off.

As far as the FM Stereo LED goes. Tune the reciever to a known strong FM stereo station. Then slightly adjust a trimmer resistor on the Tuner board marked VCO to left or right while watching the FM stereo light.See if it locks in the stereo signal and stays lit.If it does leave it in that position. Note: mark the present trimmer location in case you have to set it back to the original position.
 
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Thanks, Avionic.

The FM stereo light is back on tonight, dimly - better signal at night, maybe - I'm excited for another adjustment I might be able to make myself that I can try tomorrow.

"First place I'd look is the pass transistors on the power supply board. The two TO-220 transistors on the PS board are the "pass" transistors."

I don't know how to test the transistors, or anything - hook the meter to both sides of it and see if it moves the meter, I guess?

I'm sure that if I look I will find "using your voltmeter to test electronics for dummies" info somewhere - maybe even a sticky on AK? I'm a teacher, so this is a good experience for me - having to ask basic questions that everyone else in the room has already moved way, way beyond. In the meantime, I appreciate your patience.

Greg
 
Thanks, Avionic.

The FM stereo light is back on tonight, dimly - better signal at night, maybe - I'm excited for another adjustment I might be able to make myself that I can try tomorrow.

"First place I'd look is the pass transistors on the power supply board. The two TO-220 transistors on the PS board are the "pass" transistors."

I don't know how to test the transistors, or anything - hook the meter to both sides of it and see if it moves the meter, I guess?

I'm sure that if I look I will find "using your voltmeter to test electronics for dummies" info somewhere - maybe even a sticky on AK? I'm a teacher, so this is a good experience for me - having to ask basic questions that everyone else in the room has already moved way, way beyond. In the meantime, I appreciate your patience.

Greg

Just try and lightly tap on them,with something non-metallic like the plastic handle of a screwdriver and see if it cases any pops. I'd do this with a set of cheap test speakers. If it pops chances are the solder connection is just bad and needs to be resoldered. A meter won't identify a noisy transistor.For right now we just need to eliminate solder connections as the problem.If you do find that tapping on the board/transistors causes pops, your next hurdle is getting the board loose enough to flip it over so you can eyeball the solder connections. The first time it was a little frustrating.Now I can have both the PS board and the e-cap board out in less than 10 min.I've repaired quite a few of these models.
 
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Thanks again, Avionic. I will find some even crappier speakers than mine (though I think all mine sound pretty good in their own humble way) and do that.

If I still lived in Iowa, I'd be hitting you up for repairs. (I grew up in Iowa Falls, then Hinton (over by Sioux City), went to high school in Marshalltown, then UNI.)

I need to find a cheap or free non-working CR I could learn on without worrying about it. There's a $20 "powers up, no sound" 640 on CL I've inquired about, but it's a bit of a drive. Are there any questions to ask that might make it promising? For example, is it useful to know whether it has a relay click, and if so, would it be good or bad if it did? Working lamps might indicate light use?

Greg
 
The CR-640 uses hybred amplifiers on a single chip or power pack. If no sound chances are good it has a blown chip. I think these chips are rather hard to find legit bonafide replacements.But be a good unit to practice soldering and desoldering.
 
Yeah, I was just reading that about the x40 series - it would take some of the fun out of practicing on something that had little chance of coming alive.
 
Tale of woe. Got in there again, first I hit everything with canned air again, trying to blow up under the protect relay cover - I still can't get it off - and cleaned and worked all the switches again.

Tapping on the relay box produced big pops, flickering FM Stereo light and protect mode. Came back out of protect upon turning back on.

Successfully set the idle current, or so I thought - left was at 24, right at 4. Got them both reading 10.

Hooked it back up and as I was testing, POOM. No left channel. Both fuses blown on that board. Replaced the fuses, but now it won't come out of protect, the left channel reads 22, adjusting the pot has no effect, and it is hot hot hot in there.

Unless there's something else I can check on, looks like I'm taking it in.

Oh, but the FM Stereo light comes on now. Great.

Thanks for your help, avionic. Felt like I almost had it.

Greg
 
…and it was reading 22, not adjusting, and not coming out of protection because there were blown fuses in there… duh. Something in there is toast.
 
…and it was reading 22, not adjusting, and not coming out of protection because there were blown fuses in there… duh. Something in there is toast.

Well... Now we need to learn how to test transistors.:D
Not coming out of protect,blowing fuses...Sounds like a shorted output transistor. The channel that won't adjust is the first channel I'd check.
 
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OK, now it gets real, I guess…

Those are or aren't the pass transistors you were talking about? Let me guess, located on the vertical boards where I was checking idle current, down at the bottom? There are transistors at the front and rear.
 
OK, now it gets real, I guess…

Those are or aren't the pass transistors you were talking about? Let me guess, located on the vertical boards where I was checking idle current, down at the bottom? There are transistors at the front and rear.

The final outputs are the transistors that are screwed to the large black heatsinks. Sounds like you also have issues on the PS board solder connections or relay contacts.The two "pass" transistors are soldered to the PS board and have small aluminum heatsinks.
 
Thanks - At first read, my head is spinning from the instructions about testing transistors. This may be where I reach the end of the line for DIY, for now. I'll have to read them a couple more times and see if I can screw up the courage to start testing. (First thing I saw too, is that I need a multimeter with diode testing… which my new one doesn't have. D'oh!) I do have a colleague at work who is reputed to have skills. Who knows if he's ever worked on anything similar. Maybe I can point him in the right direction based on this conversation, though.

If I did have an amateur tech / friend / colleague type go in there and I were directing traffic as to where to look and what to replace, what should I get replaced as a matter of course? I think I saw lists of such things in other conversations here with you, Merrylander, others - like, "as long as you're going in there…"

After writing the above, I went looking through AK for those lists and found a daunting amount of complicated (to me) stuff that people on here really know a lot about from working on tons of Yamahas. I see why people amass this knowledge and do it themselves. I don't know if that means I should just bite the bullet and take it in to Hi-Fi Heaven or Music Technology (DC area high-end / vintage audio repair), assuming I'll probably have to anyway at some point… or if I'd be basically taking the same chance even with a jack-of-all-trades tech at one of those places. Probably the former. That takes some of the fun out of it for me - I get a kick out of beating the market. If I keep the service to $300, I'm looking at about what I would pay on eBay with a decent deal for a (maybe) working one after my original $100 purchase. But I guess I'd have a warranty and a decent chance of many years of awesome sound. Something to think about.

(There's another guy at work who supposedly has a "vintage hybrid tube receiver with crazy high wattage, like over a hundred" that he's going to give me. He didn't remember the make or model, but he said it was a mainstream brand. I don't think such a thing really exists, but I'm curious what he shows up lugging. He does work in A/V technology, but I'm still expecting it to be hilarious. But that's another story.)

Going to have to pick up a mid-watt 70s Onkyo or Technics or something reasonable and available like that on CL to listen to in the meantime. My former Denon black box is killing my ears after this taste of clear, smooth Yamaha power.

Greg
 
OK, now it gets real, I guess…

Those are or aren't the pass transistors you were talking about? Let me guess, located on the vertical boards where I was checking idle current, down at the bottom? There are transistors at the front and rear.

http://www.audiokarma.org/forums/showthread.php?t=201303
All bipolar transistors have 3 connections ( emitter,base and collector). Your final output transistors are a TO-3 case style. The case itself is the collector and the 2 pins sticking out of the bottom are the emitter and base.
 
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