Yamaha CA1000 popping fuses.

[Scrounja]

Hi all, I am persevering with my Yamaha CA1000 - love hate relationship. Firstly I know it needs a good Deoxit, but the controls are difficult to get too, I'm thinking maybe take the face off, but the knobs wont budge - any ideas. Now for the fuses on the side (by 2), the right one blows, when replaced the left one blows?? I have searched the archives and found another member who had the same issues, Avionic put forward some possibilities "One fuse is for the positive rail the other for the negative rail. TR609-TR612 shorted would cause these fuses to blow". Avionic was also good enough to attach a schematic, my eyes are bad and I cannot read it, can anyone help me out with some larger Schematics. Appreciate your time, Scrounja.

 

[petehall347]

try pressing ctrl and + ... to zoom in ..

 

[Scrounja]

Thanks heaps, problem solvered.

 

[avionic]

I'd first pull the two output transistors (heatsink mounted) from the side thats blowing fuses and check them for "shorts". Just unscrew the four screws holding them down and unplug them from there sockets.Careful not to damage the mica insulators and make note of which transistor was plugged into which socket.:thmbsp:

 

[Scrounja]

Avionic, I was kinda hoping you may pop up. Shall study that diagram a bit more, and have a crack at your suggestion in the morning. Do you have any tips at getting that Deoxit in behind the face? Thanks mate.

 

[xoaphexox]

You may need a hex key to loosen the bit holding them on before some knobs will come off. Otherwise you can try using a towel wrapped around the knob to give you more of a grip to pull them off. Unless the previous owner glued the knobs on, they do come off with enough force. Then the whole face plate can screw off. Disassembly is the only way you are going to get any deoxit in those pots.

 

[avionic]

Alot of disassembly required to get access to all the switches.Follow the disassembly procedure in the service manual. The CA-800 is almost identical chassis. Heres its SM.

http://sportsbil.com/yamaha/ca-800-sm.pdf

 

[brutal]

Don't pull hard on anything without consulting a service manual or asking for help.

As we all know there are often hidden set screws (Yamaha tuning knobs) or other recommended removal methods that will prevent damage to you, the component, or facia.

Most every knob on a Yamaha over 1/2" is secured with at least one set screw. There are exceptions, but that's the rule.

 

[avionic]

Most every knob on a Yamaha over 1/2" is secured with at least one set screw. There are exceptions, but that's the rule.

Exception on the CA-1000 the inner balance control knob behind the volume knob, it pulls off real hard after removing the volume knob ( which has two set screws --1.5 or 2mm) Use the " two tablespoon method " to pry it loose.:thmbsp:

 

[Scrounja]

Went and purchased some Hex Keys, good quality (Made in the USA), I'm glad I did, they were tight. They are 2mm, upon inspection the smaller round knobs appear as they will come off with a bit of gentle pressure (with the Table Spoon method) - haven't tried as yet, tommorow job. The closer I look at this Amp the more you see, they are built well, I have never heard one, so I don't want to rush it & stuff it up.

 

[brutal]

Exception on the CA-1000 the inner balance control knob behind the volume knob, it pulls off real hard after removing the volume knob ( which has two set screws --1.5 or 2mm) Use the " two tablespoon method " to pry it loose.:thmbsp:

Yup. The A1 outer volume pulls off, the inner is set and aligned to the outer.

Went and purchased some Hex Keys, good quality (Made in the USA), I'm glad I did, they were tight. They are 2mm, upon inspection the smaller round knobs appear as they will come off with a bit of gentle pressure (with the Table Spoon method) - haven't tried as yet, tommorow job. The closer I look at this Amp the more you see, they are built well, I have never heard one, so I don't want to rush it & stuff it up.

Yes, smaller round tone control, etc. knobs pull off. Never had to spoon any, but a solid grip was often needed. You should just need to spoon the balance control off if you can't pull it off.

Paddles are always screws. Volume usually screw. Some split L/R Volume controls or Volume/Balance are screw/pull or pull/screw.

 

[Scrounja]

O.K., have the knobs off, feel like I'm still getting nowhere. The knobs have a lug on the right hand side, with a split, it looks like Deoxit could go in on the left hand side? (Photo 1). The switches are on a slide, and still hard to get to, maybe the bottom needs to come off? I had a local Tech look at it some time ago, he tracked power out of the Capacitors, and he suspected it could be the Rectifiers, he then told me it would cost $80 per hour, plus parts & consumables - we parted company. It has sat in a box for over 20 plus years, and there is corrosion on most solders. I feel it is worth persevering with, the face has absolutely no marks at all, neither does the case, it still has the original box from purchase. I think I will have to spend a great deal of time detailing this unit befor I get ahead of myself, thanks fellas.

 

[brutal]

You need to be around the backside of the switches/pots. Nothing you do from the front will help unless you're just trying to lubricate a shaft.

Did you review the dis-assembly procedures in the SM link Avionic sent?

Here's the pic from the CA-1000 SM.

This may be deeper than you want to go...