PSX 7501 W/Mayumi V4 - won't boot backup

So, I recently modded a 7501 PSX with a Mayumi 4.0 chip. It seems to have a hard time booting backups after the system has been off for a while, but if I boot an official PSX disc upon boot, it seems to load backups just fine.

This seems like an odd problem. Why would it boot a backup to the menu, but after putting in a real game it loads backups fine. Could this be a laser issue, or did I fubar my install. Backups play fine after loaded a commercial disc, but it seems rather arbitrary that it would do so. Any thoughts?

 

I guess you should recheck your connections. My common problem with the chip, besides having to solder onto a tiny resistor is that the disc drive acts erratically.

 

If you check all wires and they are fine, try adding a 100nf cap between pin 1 and pin 8.

 

I'll be double checking all my connections this evening. I got a few 100 nf caps, so if everything checks out, I'll add that in and report back. Thank you both!

 

Can't say I understand it, but the cap addition worked. Everything boots first time now. Thanks BadAd.

 

No problem.

https://en.wikipedia.org/wiki/Decoupling_(electronics)