PSOne Doesn't Read Discs Despite Working Laser

I've decided to give up on modding the PSOne model after two failed attempts, especially with f-king point 3. I have one left and I do not plan on modifying at all. This one has the odd problem of giving up reading a disc after booting past the Sony logo. I have tested its cd drive, and it worked on another system. But on this particular one nada. I examined the board and everything appears to be normal, nothing loose. Does anybody know what's the deal with this one?

 

AHAHAHA. I had this problem and sold the PS1 that did that to @MonkeyBoyJoey because I was so damn fed up with it. Not sure if he got it working or not, but he'd be where I'd start to ask. Also, have you tried another complete drive on it?

 

Yes. I used two other functional drives and no go.

 

That PS1 is still sitting on top of my PS2 right now. Still without a laser.... Not sure what to do with it but I think I'll put PSIO in it someday. It's a SCPH-1001 for anyone wondering. Never got games working with the laser from my 7501 but I think I got an Audio CD working. I'll try it again in a few weeks. Worst case it'll make a nice CD player lol.

 

What exactly is is doing? If the drive does nothing at all, it's possible the door switch is bad...

 

It spins for a few seconds, and then gives up.

 

OK, try moving the sled out to the edge of the disc and seeing if it seeks back when you close the door switch - also see if the lens moves up and down when the door switch is closed. No seek and/or focus is normally a BTL driver problem. If those two are OK and in still doesn't work, then suspect either he RF amp chip or the transistor that amplifies the laser diode drive.

 

Oh balls. I just looked up the BTL you're talking about. I guess the bright side is that it's a big SMD part. I'll have to go to the store and buy some enameled wire unless a job of that size makes the job rather easy. Though tell me about the RF amp and transistor.


So I pushed the sled to the end, but the laser goes back and place and that's it.

 

The drive transistor for the laser is Q701 in that photo - it's just above and to the left of the socket for the optical drive. You can also measure the voltage drop across those 2 resistors that are above it to get an indication of the laser current.

 

Does anybody know where the RF Amp on the board is?

 

i found where it is and changed it as well as that transistor. Didn't fix the problem. So I have the ba chip removed at the moment. Waiting on some new ones I ordered..

 

Could be the spindle motor, SCPH-100x is sometimes picky about that.

 

He said hes used 2 other drives, so I dont think its the spindle motor.

I have had similar problems and had to replace the BA chip

 

Yeah its not the laser assembly at all. i tested it on a working psone. I'm pretty confident the ba chip was bad. Is there a sure fire way to test the ba chip that anyone knows of?

 

Here are the locations of all three chips for anyone interested:

 

So I ended up replacing the ba chip , reflowing the whole board and then washing it. Its fully working now dc16.

 

Sorry in advance for bumping an old thread, but i started having a similar problem with one of my units recently and felt like starting another thread was unnescesary as the problems appear to be similar.

Anyway, a PSOne (Model SCPH-102) i have suddenly stopped reading discs again after i didn't touch it for a while. At first it seemed like a bad drive transistor (which i replaced), but now whenever reading a disc it just gives up after a few seconds in a similar way to what OP described. Funny thing is, this time it appears as if the disc spins more slowly that what i typically saw before.
Just to point out, the drive assembly itself is working fine on another unit and the problem appeared before i changed the transistor (there was a different problem with it). Also i want to note that my unit uses a Panasonic AN8732SB Driver instead of a BA chip.

So my question is, is there a way to check for sure whether the problem is really caused by the Driver or if it's rather the RF Amp chip?

 

Pretty sure it spinning slower is a sign it's the ba/driver chip.

It's almost always the ba/driver chip

 

Alright, sorry for bumping this again, but it seems i can't find any replacement AN8732SB's or even its datasheet anywhere.
If anyone happens to know, can you please tell me whether the board's traces make it possible to simply replace the Panasonic driver with either a BA5947FP, BA5977FR or a BA5977FP instead?

 

There are only 2 board revisions. So assuming you can find a pic of both with the ba chip, then it will work as a replacement.

I do not know if one revision used the ba driver and the other used Panasonic.

Edit:
Google-fu says they are pin compatible.