Help to fix Mission PCM II

[Tombeur]

Mission pcm 2 no sound

Hi,
Just plugged back my pcm 2 after years and no sound comes out of it... seems also that it is a little stubborn when playing... giving error sometimes but sometimes track plays.
Any idea if this can be repaired ? Is it worth it? Anyone interested of buying for parts?

 

[poynton]

Of course it is repairable and is worth it!!

Where are you?

 

[Tombeur]

Hi,
I’m in south France ! What do you suggest ... ?
Last time it was plugged in I seem to remember it was fine... but time might have done its thing ? Probably nothing too bad but hey.. ! Remote is working too

 

[listentwice2002]

I had a case of DC-offset at the output OP which was cured by resoldering bad joints at the voltage regulators. Still the upper board was sensitive to knocking, toggling sound on and off. I resoldered the pins of the small board that is stacked over the DAC chip at the left corner (seen from the front) and the unit played well again. I would not discard a PCM II.

 

[Bull67]

Hi, I'm also the proud owner of a PCM II, from new, but it shows since last month the same problems as mentioned earlier; uncontrolled closing of the disc tray, error on disc when a disc is inserted, etc. I would like to get it back in operation as I like the sound. I wonder if anyone was able to solve these problems and how.

 

[tiefbassuebertr]

a friend tell me, he absolutely love this CD player but he have a slight issue - the display goes randomly blank.
Is it a LCD-Display with background illumination or a VFD version?

According service manual of CD660/670 the type is FV112 and the Philips order code "4822 130 90403"

But the question is, whether Mission had a custom made version in use.
Thanks for an advice.

 

[Bull67]

Hi, I'm also the proud owner of a PCM II, from new, but it shows since last month the same problems as mentioned earlier; uncontrolled closing of the disc tray, error on disc when a disc is inserted, etc. I would like to get it back in operation as I like the sound. I wonder if anyone was able to solve these problems and how.

Small update.
By "accident" I found some old guys doing repairs on older hifi equipment, besides engineering and repairing tube amplifiers . They where able to repair my PCM-2. It appeared that the power supply was not working properly, creating the un-controlled open and closing of the tray and the error on reading the CD. They mentioned that they also replaced the MAB8461P/W127 controller chip, but I haven't taken the player apart (yet) to check if it was replaced.

 

[tiefbassuebertr]

Who can upload the genuine PCM-II service manual or at least the schematic ?

I know, that for repair service purposes the service manual of various Philips Marantz or Grundig cd players with CDM2 or CDM4/11 helpful enough - e. g. Grundig CD9000 - go to
https://www.vintageshifi.com/repert...ge.php?pdf=Grundig-CD-9000-Service-Manual.pdf
and
https://www.hifiengine.com/manual_library/philips/cdm-2.shtml
Nevertheless I want to have the one from Mission resp. Cyrus.

Thank you very much

 

[tiefbassuebertr]

I have probably fix the error without service manual. After switch-on the cd player is dead, but screen (VFD display) looks like a blinking christmas three illumination.
The pos. rail of 5VDC provide only 3V5.

Because the input voltage of the associated voltage regulator was above 9V, I suspected the 5V regulator itself as the part causing the error but no changing the situation after replace by a new part.
After temporarily cutting of numerous conductor tracks I note after disconnect both the operating processor board and the Philips processor IC MAB8461P-W127 itself - go to
https://www.diyaudio.com/community/threads/wtb-mab8461p-w127-mission-pcmii-controller.121935/ that supply voltage on the mentioned regulator rises up to 5V.

I note a resistance of 120R between the supply pins of this processor (that means idle current of approximately 40mA) and I guess, this IC must be replace.

Was this mask programmable processor IC only made for this model from Mission or are there also some Philips/Marantz cd player models, where this IC is in use ?

Thanks for an advice.

 

[huggygood]

I only saw the MAB8461P-"W127" in the Mission CD player, the suffix "W127" seems to be the dedicated program, the only solution seems to be to have to buy another broken PCM II and pray that this IC be intact.

 

[tiefbassuebertr]

maybe the PCM7000 could have same MCU-unit in use - go to
http://insideclassicaudio.blogspot.com/2012/01/mission-pcm7000.html
https://www.diyaudio.com/community/threads/mission-pcm-7000-enquiries.370910/#post-6618451
https://www.diyaudio.com/community/threads/philips-cd650-mission-pcm7000-differences.60144/page-2
https://pinkfishmedia.net/forum/threads/mission-pcm-7000-repair.262963/
https://vintage-audio-laser.com/A-l-atelier-page-35

 

[huggygood]

I have a PCM7000, I can watch this weekend if you want.

 

[tiefbassuebertr]

I have a PCM7000, I can watch this weekend if you want.

image No 3 show this processor-IC after zoom - it is the MAB8441P-T054.

 

[huggygood]

Next ...

 

[tiefbassuebertr]

Images of my device with faulty user processor

 

[huggygood]

I have a whole stock of philips machines from the 80s and 90s, I'll see if I find this in one of them.