Noisy Mission PCMII transport

[Audiofirst]

Hi everyone

My Mission PCMII (aka Philips CD650) is noisy when playing a cd. The whole machine vibrates, as if something is spinning off- axis inside. Playback is unaffected.

Love to hear your thoughts, I will check up again tomorrow evening (Aussie time!)

regards
Blake

 

[Fin]

Hi Blake

It could be that the clamp is not holding the disc properly or that part of the suspension has come undone.

You could try removing the cover and have a look to see what happens when you load a CD.

Be careful and you shouldn't need to touch anything inside to just see what is happening. If you do decide to touch something inside - remember to switch off and disconnect the power. Also - try to work ESD safe as the laser diode and most of the chips are very sensitive.

 

[Audiofirst]

Fin

Thank you. I'll check it out and let you know what I find

Cheers

 

[Audiofirst]

Well, just pulled it apart, found enough dirt and dust to grow sprouts on the servo board. No dramas with the clamp arrangement, I think the CDM4' 20yr old suspension may be starting to give way, and discs with the slightest of warping are setting up a real rumble in there. I can hold a finger on the table during operation and it quietens down.

Well, I'll leave it as is I guess, because it's not affecting playback. Good opportunity to give it a good clean. Thanks for your input Fin

Blake

 

[stephensank]

You just put your finger on the real problem. If you take apart the disc clamper, you will find that the plastic bit upon which the ball bearing in the middle of the clamper disc rides will have a "divot", i.e. a wear spot from the ball. Just sand this plate area down to as flat & smooth as possible(really, really smooth), and then apply a blob of thick grease & it should work perfectly for the next decade or so.

 

[Fin]

....and make sure that the grease is not petroleum based. A silicone based grease won't attack the plastic.

 

[Audiofirst]

Stephensank and Fin

Thank you both once again. I'll get back under the bonnet with some silicone-based grease and see what happens.

cheers