Pioneer CDJ-800 MK2 Disk Reading issue

Downtown Radio was one of my Authorized Service Centers when I worked for Pioneer. They are no longer in business. The issue that Nathan is having, is quite different than a loss of power or ground, caused by an bad IC Protector, which is merely a complicated fuse. Unfortunately, I think you damaged the Optical Pickup(laser) when you installed it. This part, as well as most parts in this unit, are ESD sensitive and without taking the precautions, that pickup may be useless now. For more information, please visit my website at audioserviceclinic.com. You may contact me directly through the website. Thank you.

The switch under the button is most likley at fault.
Cue buttons and cue switches are available and easy to change.
Switch :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-CDJ-800-MK2-PLAY-PAUSE-CUE-TACK-SWITCH-/300408370512?cmd=ViewItem&pt=UK_Mixers&hash=item45f1bbf550

Mk1 button :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-mk1-PLAY-PAUSE-CUE-BUTTON-BANK-ASSY-/300397768495?cmd=ViewItem&pt=UK_Mixers&hash=item45f11a2f2f

Mk2 button :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-mk2-PLAY-PAUSE-CUE-BUTTON-BANK-ASSY-/260588810664?cmd=ViewItem&pt=UK_Mixers&hash=item3cac4db1a8

Mk1 lasers are availble here :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-MK1-CDJ-LASER-OPTICAL-PICK-UP-ASSY-NEW-/300358857324?cmd=ViewItem&pt=UK_Mixers&hash=item45eec8726c

Mk2 lasers are availble here :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-CDJ-800-MK2-LASER-TRAVERSE-DECK-ASSY-NEW-/260616571438?cmd=ViewItem&pt=UK_Mixers&hash=item3cadf54a2e

email for more details [email protected]

The switch under the button is most likley at fault.
Cue buttons and cue switches are available and easy to change.
Switch :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-CDJ-800-MK2-PLAY-PAUSE-CUE-TACK-SWITCH-/300408370512?cmd=ViewItem&pt=UK_Mixers&hash=item45f1bbf550

Mk1 button :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-mk1-PLAY-PAUSE-CUE-BUTTON-BANK-ASSY-/300397768495?cmd=ViewItem&pt=UK_Mixers&hash=item45f11a2f2f

Mk2 button :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-mk2-PLAY-PAUSE-CUE-BUTTON-BANK-ASSY-/260588810664?cmd=ViewItem&pt=UK_Mixers&hash=item3cac4db1a8

CDJ800 lasers can and do fail.

Mk1 lasers are availble here :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-MK1-CDJ-LASER-OPTICAL-PICK-UP-ASSY-NEW-/300358857324?cmd=ViewItem&pt=UK_Mixers&hash=item45eec8726c

Mk2 lasers are availble here :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-CDJ-800-MK2-LASER-TRAVERSE-DECK-ASSY-NEW-/260616571438?cmd=ViewItem&pt=UK_Mixers&hash=item3cadf54a2e

email for more details [email protected]

CDJ800 lasers can and do fail and will say disc error if they do

Mk1 lasers are availble here :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-MK1-CDJ-LASER-OPTICAL-PICK-UP-ASSY-NEW-/300358857324?cmd=ViewItem&pt=UK_Mixers&hash=item45eec8726c

Mk2 lasers are availble here :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-CDJ-800-MK2-LASER-TRAVERSE-DECK-ASSY-NEW-/260616571438?cmd=ViewItem&pt=UK_Mixers&hash=item3cadf54a2e

email for more details [email protected]

CDJ800 lasers can and do fail.

Mk2 lasers are availble here :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-CDJ-800-MK2-LASER-TRAVERSE-DECK-ASSY-NEW-/260616571438?cmd=ViewItem&pt=UK_Mixers&hash=item3cadf54a2e

email for more details [email protected]

CDJ800 lasers can and do fail.

Mk1 lasers are availble here :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-MK1-CDJ-LASER-OPTICAL-PICK-UP-ASSY-NEW-/300358857324?cmd=ViewItem&pt=UK_Mixers&hash=item45eec8726c

Mk2 lasers are availble here :-
http://cgi.ebay.co.uk/PIONEER-CDJ800-CDJ-800-MK2-LASER-TRAVERSE-DECK-ASSY-NEW-/260616571438?cmd=ViewItem&pt=UK_Mixers&hash=item3cadf54a2e

email for more details [email protected]

Chances are the laser has failed.
http://cgi.ebay.co.uk/PIONEER-CDJ800-CDJ-800-MK2-LASER-TRAVERSE-DECK-ASSY-NEW-/260616571438?cmd=ViewItem&pt=UK_Mixers&hash=item3cadf54a2e

Any error codes??? you must provide some more info... is the screen blank? When you are trying to insert a cd do you hear any noise from the mechanism?