Yamaha CR-620 Pop sound when shutting off

[petehall347]

Nikko Newbie's Nikko 440 we've been trying to help on.

yes i was waiting on a reply . i just bumped the thread ..
anyway enough off topic chatting on this thread ....

 

[avionic]

99% of the time a "pop on shut down" is burnt out lamps.

 

[Natsil42]

So if it has been converted to led then this is likely the issue? Like I said the lights are working but if they are led then there is not enough load from them and thus... so put back original lighting or add... what to make this copacetic?

 

[llwhtt]

If the LEDs are run at full current, 20ma or so,40ma total, that's 1/3 of the load that the lamps,120ma, present to the power supply. The LED conversion would need resistors to limit current to the LEDs and another resistor to create more of a load. Since nobody runs the LEDs at full bore it would take some experimenting to make it look correct, especially if you want that pale green Yamaha look.

Craig

 

[Natsil42]

So if they have been replaced with led lights I either have to get the original lamps or add what...? To compensate?

 

[Natsil42]

Oh, thanks Craig!

 

[Natsil42]

Thanks to everyone for sharing their k-naledge, this has got to be the best forum experience I've ever run into!!

 

[reydelaplaya]

Replace is best. Cleaning relays is usually only a short term fix. Did you replace the lamps or is this converted to LED ?

can you explain to me exactly HOW lamps would cause popping to the speakers?

the lamps when working are drawing current so relay operates correctly at power off .
when not working the relay off time is extended hence the pop .
well its something like that .. its been covered before .

The lamps are run off of the same power supply as the protection circuit and present a fairly high load compared to the relay circuit. When power is switched off the power supply should collapse immediately and relay de-energizes immediately also. Without lamps the heavy load is not there and the relay power supply doesn't collapse as fast, slower than the amplifier circuit and that's where the pop comes from. The amplifier circuit is collapsing BEFORE the relay circuit, just what you don't want.


Pete beat me to it!


Craig

As Pete and Craig have reitterated. Its due to the lamps and the protect relay are on the same power supply. This issue is prevalent in most of the CR models.

If the LEDs are run at full current, 20ma or so,40ma total, that's 1/3 of the load that the lamps,120ma, present to the power supply. The LED conversion would need resistors to limit current to the LEDs and another resistor to create more of a load. Since nobody runs the LEDs at full bore it would take some experimenting to make it look correct, especially if you want that pale green Yamaha look.

Craig

So if they have been replaced with led lights I either have to get the original lamps or add what...? To compensate?

It's funny, my CR-1020 had been making a pop at shutdown too, but I just attributed it to being kinda old. It did have a couple lamps out though.

I ended up replacing them with resistored LEDs, but I don't recall the pop going away because I just got into the habit of switching the speaker selector to 'Off' before I powered down.

One thing I can attest to is that I ended up pulling the LEDs and putting in a full set of the correct grain of wheat lamps and it hasn't popped since (and sometimes I forget to switch off speakers), but I never would've guessed it was related to the lamps.

To OP: your lamps are available on Amazon. A pack of 10 for like $5 - they're the same ones I used in mine. From that page in the Yamaha owner's manual:

12V 60mA 3mm

CEC Industries 7219 Bulbs, 12 V, 0.72 W, Wire Terminal Base, T-1 shape (Box of 10) https://www.amazon.com/dp/B00L8BR76A/ref=cm_sw_r_cp_api_uJ7YxbMV9X28Q

 

[Mr. Yamaha]

I have the same issue with my CR-800. I converted it to LED with the proper resistors, but the shutdown pop remained.

Also strange: the LEDs have become half as bright since they were installed 2 months ago

 

[llwhtt]

There will be two sets of resistor(s), one to get the LEDs at a proper current/brightness and one to get the current draw back to what it was with the incandescent lamps, in that order. Not sure about your brightness problem. You'll need to open it up and take some measurements to see what changed.

Craig