NEED ADVICE BUTTONS NOT WORKING MPC 4000 1.71

i recently purchased a mpc 4k at my local pawnshop and for a minute i thought this thing was more difficult than the other mpc's I'm familuar with.(60,2k,2kxl,&ren),but I am convinced there is something wrong here.

i opened it up and besides being dusty as a desert everything looks to be original and in good shape.
there is a 2 inch crack on the monitor black part of the screen (it seems to be on the inside thought)
the screen does have a line at the bottom when turned on.

the problem is i cannot navigate for the life of me unless i plug a keyboard up but the zoom option on my keyboard doesn't seem to work with the 4k (could be me) i don't know but i can't zoom out in region.

i found a service manual and did the panel test and found some buttons not lighting up:
Q link, erase,note repeat, pad bank "F",program,<> step,& most important window button.
i manage to load up some drums and make a quick loop but I'm very limited as i can't dial in with the curser to change some settings.

i sent an email to MPCs stuff and was referred to mpc forums for help as they would need the machine in front of them to service.
any thoughts on what the issue is? could this be a pcb operation assembly problem?

You can do a panel test...

Panel Test Mode
To enter the Panel Test Mode, press the GLOBAL key while holding down the SHIFT key in the GLOBAL page [F1] of the GLOBAL Mode.
• Moving the Q-link knobs changes the graphics accordingly.
• Tapping the PAD shows the amount of pressure applied on the bar graph.
• Switching the FOOT Pedal on/off changes the graphics accordingly.
• Turning the JOG wheel increases/decreases the value in the Data field.
• Pressing the key shows its name at the bottom of the screen. For those keys with the LED, the LED is turned
on/off.
• Pressing the [F1] key stops the key test.
• After stopping the key test, pressing the mode key will abort the test mode.
• While the key test is stopped, pressing the SHIFT key and [F6] key shows the A/D converted value of the
Q-link/ PAD.

Might need some tact switch replacements?

My go to for this though is to try and detach and reattach cables. If you've got some deoxit I'd try getting that in there as a second pass, because these things are older and tend to collect grime and oxidize.

Only make one change at a time though... in case you bung something up on accident, it'll make it easier to triage what might have gone wrong that you introduced.

NearTao wrote:Might need some tact switch replacements?

My go to for this though is to try and detach and reattach cables. If you've got some deoxit I'd try getting that in there as a second pass, because these things are older and tend to collect grime and oxidize.

Only make one change at a time though... in case you bung something up on accident, it'll make it easier to triage what might have gone wrong that you introduced.

i almost sprayed some crc wire dryer on it lol.wire dryer can be used on electrical components,but I'm not sure how it will effect the board it self.so i'll head up to walmart and get some deoxit.

Thanks for explaining the panel test!

I have 3 broken cursor buttons around the jog wheel on my 'new' 4k, they click just fine but dont do anything. what might the problem be with them , the switches?
can i use a computer keyboard instead? could i just fix them by tidying up or they need to be replaced?

Regarding to using usb keyboard - yes, you can according to the layout: https://www.akaipro.com/amfile/file/dow ... roduct/76/