hifi engine

Yamaha CR-1020 cooling

I was just wondering about something. I recently repaired a CR-1020, changed the bulbs, cleaned all the pots and switches and replaced the tuner cord. While I was inside I noticed none of the rubbers were hard yet. I don’t think this receiver was used much and looks new inside and out. I was wonder about installing a small 4” electronics fan that I have over the top cooling grate and plugging it in to the switch power receptacle on the receiver. The fans I saved are 120 volt and I have several. This would blow a nice breeze through unit keeping everything cool. What do you guys think?.....Over kill or good idea?



Re: Yamaha CR-1020 cooling

I have worked on an number of those receivers. I believe it is overkill and would only promote dust intake into the chassis. These receivers are approximately 40 years old now and heat issues have never been a problem.

-bob

Re: Yamaha CR-1020 cooling

Thanks Bob for taking the time to respond. I was just curious because they do feel warm to the touch.

Re: Yamaha CR-1020 cooling

Hi,

Double check that the bias is set correctly. After adjusting, let the unit idle for 30 minutes and re-check.

-bob

Re: Yamaha CR-1020 cooling

I’ve found a fabulous YouTube video explaining this on the Cr series. Thanks for the suggestion Bob. I’ll be sure and check it..

Re: Yamaha CR-1020 cooling

Would that procedure be explained in the service manual? I’ve got a Fluke meter and I’m familiar with equipment repairs but have never adjusted bias voltage on a receiver before. Should be easy if I can identify the correct sampling points and pots to adjust. I was a radar technician 40 years ago in the AF and have been a professional mechanic for 35 years. I remember enough to be dangerous from my radar tech days!

Re: Yamaha CR-1020 cooling

Don't stand in front of the CR-1020 when adjusting the Bias, it will burn a hole clean through your skull.... :)

Re: Yamaha CR-1020 cooling

Hi,

Yes, the instructions are in the service manual. Very simple to do using a multimeter. You are just adjusting a pot for a voltage across a resistor that is in series with the output transistors. When you adjust it the circuit will then need to settle to reach themal equilibrium. That is why you want to adjust it and then let it sit idle for 20 minutes or so and re-check it.

One word of caution. When putting the cover back on, be extremely careful that the metal support from the wooden cover doesn't get caught on the dial string. If it does and you turn the tuning knob you will more than likely break the dial string. If you do end up breaking it, you will NEVER make that mistake again. LOL

-bob