MPC500 Startup

Daaaamn it. MPC500 Startup.
After all the problems with my MPC2000, successfully installing a CF reader, then ordering the new MPCSTUFF screens only to have it lock up after a few minutes every time, after dealing with all that total money pit frustration, I was once again excited because my friend had an MPC 500 he had never been able to figure out and if I could get it to work I could have it. Easy right? I've fixed buckets of analog synths, assorted telephones, i'm pretty handy with a soldering iron, but now all I see is...
MPC500 Startup.
I have reinstalled the OS, sometimes it will hang on the screen that says 878 completed 878/878 on the OS install and not reboot. I have wiped the thing as thoroughly as I can figure, yet still all I get is MPC500 Startup.
Occasionally, now this is just every once and a while, if I turn it on and walk away for 5-10 minutes it will boot up finally. There is no expanded RAM installed mind you so that is not the problem, this is just a stock MPC500.
I put batteries in it, it does the same thing.
I have been trying to find a solution for this issue for days and nothing seems to be working, I have taken this thing apart a little to see if there were any glaring issues to no avail. Help me MPC forums you're my only hope.

My first MPC was a 500 from Guitar Center. It was a floor model. Being totally new to MPCs, I actually had a really hard time learning it because it was so inconsistent. Samples would drop out. It would crash. Audio would cut out sporadically. I finally came to realize, after reading the manual several times that it was the machine that was **** up, not me. Sent it to repair, spent a bunch of money. It came back in exactly the same shape.

Sometimes you eat the bear, sometimes the bear eats you. Sounds like you've had a run of bad MPCs.

Sounds like a corrupted CF card or the pins of the card reader could be bent inside. Also could be bad internal RAM.

Like Meso said, sometimes you get a lemon, but these are known to be incomplete MPCs. My 500 works well so far, but sometimes pads play by themselves like if I hit pad 1 then pad 10 plays too, making it frustrating to make a sequence because sometimes I got good stuff flowing then its all ruined for one pad.

Get a dianostic check-up at an authorized Akai dealer and if he has bad news, then sell it "as is" and save up for a MPC1000. My 62 cents.

You might want to power up the 500 while holding the ERASE button. That tells you a bit whats going on with the memory.

Thank you for the responses, I'll give the erase thing a try again if it will move past the Startup screen to get me to that point.

I have ordered some more stick RAM I wonder if that would change anything...

I'll keep fussing with it, but I feel you about the 1000 thing, maybe i'll sell the 2k and see what repairs are on the 500, sell them both and get a 1k, from what I have heard in here so far it seems to be one of the more reliable models.