Restoring unreadable PSP UMD

Hey everyone,

I hope this is the best section to post in for this. I picked up what I believe to be a prototype UMD. I'm having trouble getting it to read. The disc itself doesn't appear to have a lot of scratching or damage, but it simply will not read. Are there any suggestions or best practices one can follow to get problematic UMDs to read? It's worth noting that I tried multiple PSPs that read retail UMDs without issue with no change. Thanks for any advice!

 

Are you sure it's actually a game and not one of the discs that @Paulweeze71 is selling?

 

I'm not sure what it is, exactly. I have one other prototype UMD with an early build of a game on it. I'm able to read that one just fine.

EDIT: I just looked more closely. It's a UMDT-99813, which I have read is also called a "checkdisck silver UMD" or "production trial".

 

Okay, so thank you to Borman for pointing me to Paulweeze71. After a quick eBay search, I see his listing for the same type of disc. His auction links to the ObscureGamers forum thread on the topic: https://www.obscuregamers.com/threads/psp-checkdisc-scan-discussion.22051/

Here's a photo of my disc: http://www.myvideogamelife.com/a/vgm/ag/ag-ninjistar-psp-checkdisc-umdt99813-09052017.jpg

I had originally thought that the writing was a name and a date in English. I didn't look at the bottom writing too closely. Now I'm wondering if it's in Japanese.

 

It is interesting there's writing on yours. Most the ones I've seen are totally blank.
The bottom looks like a date to me, and ending in 07 would be spot on, the PSP was definitely relevant in 2007. It definitely looks like 3 sets of digits with slashes in between, no Japanese characters look like slashes except when writing a date.

Anywho, an explanation of the PSP CheckDisc as quoted from user mathieulh in that OG thread:
"Those were used to test raw sector reads of the UMD drives in service centers (in conjunction with a specific JIG memory stick in service mode on the psp)
You can read these UMDs by putting the drive in TEST mode and reading sectors from the UMD controller's memory. (it'll be either encrypted or garbage, if encrypted, you need the right set of idstorage keys to decrypt the AES portion of it using the spock cmd 0x09 key)
The encrypted discs usually contains dummy data which the JIG checks for."

 

This is exactly what I thought, but after reading that thread, I started to wonder that if it wasn't a sloppily written date, perhaps it was Japanese.

While mathieulh certainly knows more about it than I do, I'd still love to dump it, decrypt it, and take a look!

 

Well you wouldn't be the only one, looking at that thread. I'm also curious, so if someone manages to decrypt one you can bet your ass I'm reading about what was found

 

That JIG memory stick is key for dumping one of these, aside from mathieulh idk who else has one.

Some of these disc have no writing, some marked with a code and dates, some are in game cases and some in video cases, some with labels with serial numbers and one had a label in Japanese that said "Production Trial" which gave us the initial theory it was for testing the UMD manufacturing process which was debunked. I'd love to see more development on this though so if anyone else has a JIG memory stick, let me know and I'll supply a disc (if for whatever reason you don't have one already )