Forum to discuss all matters relating to the MPC1000 and MPC2500 operating systems created by 'JJ' (all versions).
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By Alpha303 Sat Dec 19, 2015 1:42 pm
HELP!!!!!!

MPC2500
JJOS128XL

I've never had any issues until tonight. Right in the middle of making a beat, I get a "FLASH ROM WRITE ERROR" and the MPC is completely froze.
After powering off then on, it asks for my password. I dig up the email and enter it. "PASS WORD ERROR". wtf?!
I reload the latest JJOS128XL 1.64. Power it back up, still asking for password, and mine still doesn't work. I noticed the Product ID doesn't match the one in the email I got when I bought 128XL with the screen. What?!

I used to run JJOS2XL, so I installed OS_XL 3.50 from the site. My OSXL password didn't work. Also, that product ID isn't what it used to be.
So I went all the way back to the free JJOS jv313. Then, installed OSXL again (password still didn't work). I saw that "FLASH ROM WRITE ERROR" once again when it first booted, but it didn't freeze this time.
And finally reinstalled the latest 128XL. Same problems. I also noticed my discount code had changed.
Both the discount codes and product ID have 0's at the beginning. My current product ID starts with 0000 now??

I've been up all night/morning trying to get this thing to work. I read about someone on here getting the "FLASH ROM WRITE ERROR" before, but he didn't mention doing anything to fix it. I depend on this thing to work.

Anyone have any ideas on what is happening?
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By Alpha303 Sat Dec 19, 2015 2:52 pm
I'm kinda thinking the same thing. I'm going to check the board over and reheat some solder joints after I grab some ZZzzz's. If it does end up being the flash rom, I'll have to replace the chip. I'm no stranger to soldering, even if it's going to be an SMD with plenty of pins.

Does anyone know which flash rom the MPC uses?
Does anyone know where the flash rom is located?
Anyone have schematics or a service manual?
Any info would be greatly appreciated.

I'm also wondering if swapping out the flash rom would change my Product ID for good. Unless I'm mistaken. Can anyone confirm?

I'll keep you guys posted on my progress, since as these machines age, this could end up becoming a common issue. Until then, any info anyone wants to share may be helpful. I'll try anything at this point.
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By richie Sun Dec 20, 2015 1:55 am
The flashrom it uses is a AM29LV641DL which is a normal 8 megabyte flash.

If you have the means to do so, you could remove the flash from an existing MPC 2500 with JJOS, clone it put it back in your 2500. The only thing is I would assume the internal serial # would be associated with the flash you cloned and not your own unit. The flashrom is located on the motherboard, there's only 1 one of its kind and you will know what it when you see it -- it's the only AM flash on the whole board.

It may also be possible to tap into JTAG points on the FPGA to reprogram the flash image that way.
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By Alpha303 Sun Dec 20, 2015 5:50 pm
Image
Thanks for the info! I found it. This is the first time I've opened my MPC from the bottom, and the main board is surprisingly accessible. Mine apparently uses S29GL064A90TFIR7. Looks like I can get a 4 pack for $10 on ebay.

Some additional info:

My Product ID has not changed again since the incident. While the current ID is not the correct ID, it has not continued to change into anything else. I'd really like to know if this was a one time glitch.

I don't think I'll need to clone the flash rom, as I'm still able to run JJOS without any issues (except for saving, obviously). Changes to my global settings are being stored properly. I've even loaded the free JJOS versions and everything seems fine. I'm surprised I'm not experiencing other issues, as I'm running thins thing with a damaged flash rom. It's really strange that only my Product ID/Discount Code changed.

I didn't hold ERASE while booting, as JJ recommends. Are we supposed to do that every time we turn it on, or just the first time we turn it on after loading an OS? Just trying to figure out how things could have gotten scrambled.

If I replace the rom, I really don't want to have yet another new Product ID. I'm assuming the product id and discount codes are based on the internal serial #. Does anyone know if this number is actually "stamped" on the flash rom, or if the rom reads the number from elsewhere on the main board?