PS1 SCPH7502 Mayumi v4 troubles

Hey fellas,

Installing a Mayumi v4 (from Bad_Ad84) in my PS1 following this helpful guide's instructions.

On the first boot attempt after installation, no CDs would boot properly at all. The kynar wire at pin location 8 on the motherboard itself wasn't soldered too well so I put it down to that - I de/resoldered this joint and I seemed to be correct, as I could boot several games and audio CDs afterward.

Unfortunately, I still get the "insert a Playstation disc" message when trying to play NTSC-J games. I haven't had the time to do continuity testing yet but I figure if there were a problem with my soldering then games wouldn't boot at all. Any idea where I might be going wrong?

 

Have u tried backups from other regions? Do retail games boot? Do u have pics of your install?

 

I once had troubles with the same board/chip, was advised to not route my wiring cda/x?? which fixed all my boot problems, have a search of the forum.

 

I haven't actually tried backups yet; just retail games from NTSC-J and PAL. Retail PAL games work fine (which makes sense because it's a PAL console), but retail NTSC-J games won't boot. Don't have pics at the moment but I'll see if I can get some later when I'm home.

Thanks for the info man; what do you specifically mean by cda/x? Is this the ribbon cable slot on the motherboard?
I think I found a post suggesting that on at least another site, but I wasn't sure what they meant. Are you able to clarify? Would really appreciate it.

 

Thanks for the info. Several things to check: recheck soldering, check Mayumi v4 chip is in modchip mode and not 'switched off' (hold reset button for 2 seconds). This thread could also help https://assemblergames.com/threads/psx-7501-w-mayumi-v4-wont-boot-backup.61864/

If u still have issues, try pm @Bad_Ad84 as he is very knowledgeable on ps1 mod chips. Good luck.

 

Need pics of install

 

Redo your soldering job... all the points. Please don't just assume that your soldering job is fine.

 

Images should now be available here.

You'll be happy to know that I've reflowed all my points (I do realize that one of the wires is not attached to the chip; it came loose when I was moving the board to get pictures. This may well have been the offending article.

I also re-routed the wire to pin 8 away from the CD drive connector.

Let me know if I've horrifically embarrassed myself.

 

So it's working now?

 

No, afraid not. Exactly the same symptoms.

 

Try removing points 3, 4 & 7 temporarily... these are for stealth and it should still boot out-of-region a game without them.

Pin 1 = power
Pin 2 = clock
Pin 5 = gate
Pin 6 = data
Pin 8 = ground

Also double check you have the pins in the correct order (not backwards for example).

 

The problem is the soldering job, every point is a cold joint.
Redo all the install, you can use flux to help the job better...

 

grab some ChipQuik or Amtech Flux , remember to not to buy from Amazon or ebay as they sell fakes (Amtech). I will leave a link below to get Amtech , i'm not sure where to get authentic ChipQuik at this point.

https://store.rossmanngroup.com/index.php/amtech-nc-559-v2-30-cc-16160.html

 

Seconding this. Also where is this attached to? https://imgur.com/a/xKy2AE2

Edit: read your comment about it breaking off. I would literally just start over, you can get some Kester flux for $5 shipped on Ebay. Sent you a message.