Do we have to have the PD-M423 CD magazine for our player

Unfortunately t isn't available anywhere. If it was, this link would find it.

https://www.google.com/search?q=%22PIONEER+PD-M6%22+replacement+magazine

..

These are not repaired because the cost to replace is very low, so just buy new.

Dear donahuecontr,
Welcome to fixya support,
It is deffinately due to magzine and magzine wheel.So replace it with new one it will solve your problem.
I think it helps.Let me know.

THERE IS NOTHING TO FIX ON THIS, THESE CD PLAYERS ARE AMAZING PLAYERS, I HAVE OWNED 11 OF THEM, I JUST CONTINUE TO KEEP UP GRADING THEM, I PERSONALLY WOULD RECCOMEND GETTING SOME MAGAZINES FOR IT, IF YOU ARE IN THE NEED FOR SOME MAGAZINES LET ME KNOW, I HAVE SOme
[email protected]

CDs go in the Upside Down position. Your PD M501 will accept PRW 1139, PRW 1141 and 163.
Lexus Models: CDX-M9071zt CDX-M8036, CDX-M9071, CDX-M9741, CDX-M9751
also:
Philips CDC-875 Pioneer CDX-FM35 Pioneer CDX-FM45 Pioneer CDX-M30 Pioneer CDX-M40 Pioneer PD-DM802

* Pioneer PD-DM902 Pioneer PD-M403 Pioneer PD-M423 Pioneer PD-M426 Pioneer PD-M450 PD-M453 PD-M455
* Pioneer PD-M501 Pioneer PD-M502 PD-M503 Pioneer PD-M510 Pioneer PD-M530 Pioneer PD-M550 Pioneer PD-M552 Pioneer
* PD-M600 PD-M601 PD-M603 Pioneer PD-M610 Pioneer PD-M630 Pioneer PD-M650
* Pioneer PD-M701 Pioneer PD-M702 Pioneer PD-M703 Pioneer PD-M710 Pioneer PD-M730
* Pioneer PD-M801 Pioneer PD-TM1 Pioneer PD-TM2 Pioneer PD-TM3 Pioneer CCS-430
* DCM-444 and DCM 777

BMW 740 OEM

The standard cartridge for the Pioneer PD-M501 is the Pioneer JD-M300 6-disc magazine, and you can find them at Amazon.com for $25 new. The JD-M300 fits a lot of different brands of CD players, not just this particular brand and model. And here's a link to a copy of the owner's manual: http://www.scribd.com/doc/22613342/Pioneer-PD-M601-M551-M501

their should be a slide button on magazine push that and cd holders should slide out

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=250344300843&ssPageName=MERCOSI_VI_ROSI_PR4_PCN_BIX_Stores&refitem=360116913384&itemcount=4&refwidgetloc=closed_view_item&refwidgettype=osi_widget&_trksid=p284.m185&_trkparms=algo%3DSI%26its%3DI%252BIA%26itu%3DIA%252BUCI%26otn%3D4%26ps%3D42

Its a com-plete unit that will not power on so it should have the part you need..

The Pioneer component 6 CD magazine changers only play normal store bought CDs, not CDs you make yourself.
sorry.