CR-1020 power supply question

Mrv8q

Audiofool
So I decided to open and clean up a 1020 I picked up over two years ago(!), and of course I can't find the replacement bulbs I ordered from our favorite AK bulb supplier. D'oh!

In a related post:

The man has a wealth of knowledge, as everyone knows by now. And he likes to share it. He Knew what the culprit in my unit (Yamaha cr1020) was before even opening it. explained what led to the problem and how he's going to fix it. I Left it there and he said to check-in with him in a week.

Well, what did he say?

The big resistors in the power supply tend to develop bad joints. Just curious if he identified that.


I have my 1020 open on the bench now, and would like to look at those big resistors tomorrow. I'm guessing these are on the buried front left circuit board that holds the two big power supply caps? If so, will it be
apparent which resistors might be suspect?

While I'm in here thought I would disassemble and clean the two center boards, and replace the two fuses on each. I've got my paint brushes ready. The fuses look like they haven't been touched in 40 years.

Everything else looks very original and untouched. No bulb lights, but all LEDs work. Protection relay works, haven't heard it play yet, though. Time to eyeball those "bad joints".

Encouragement welcomed!
 
have my 1020 open on the bench now, and would like to look at those big resistors tomorrow. I'm guessing these are on the buried front left circuit board that holds the two big power supply caps? If so, will it be
apparent which resistors might be suspect?

Here is the service bulletin for the CR-2020. The CR-1020 uses the same power supply and electrolytic board and resistors. It will help you locate the resistors.
http://sportsbil.com/yamaha/cr-2020-servbull3.pdf

http://www.mouser.com/ProductDetail/Ohmite/93J22RE/?qs=sGAEpiMZZMvNd0dY0KymzmzmepcxLzvPqwIOHRt9xgY=
http://www.mouser.com/ProductDetail/Ohmite/93J33RE/?qs=sGAEpiMZZMvNd0dY0KymzivJA4eua7tqoa4ZDqdVHDk=
 
There are 2 each 22Ω and 33Ω - 2 watt resistors. You may want to install the 3.25 watt ohmites.;)
 
Thank you, Avionic, for taking the time for your answer and the links. In the meantime, I found my bulbs
and replaced them all. 4 of the 5 were bad. It was fun to see how clever Yamaha was with their articulated
plastic snake for the tuner bulb wiring.

Cleaned face and buttons, replaced 40 year old fuses, did the deoxit shuffle, and put it back together.
I was able to dial the idle current in just right. I will order your suggested components and dive back in, in the fall.

I'm not used to horsing that big receiver around on the bench. My cute little CR-400 has spoiled me!

Again, my thanks!
 
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