Green debug psx won't read game discs. Motherboard issue?

Mine too... As I've written in the first post, audio cds are played correctly, skipping, fast forward etc. It cannot be the spindle motor since I've changed the optical group with a working one from a PSOne. And also mine has remained unused for some months...

 

I was trying to do that but is not easy...

 

Just did that, doing so caused a minor graphical glitch on the error screen when pressing on the CXD8561BQ. After some checking I think there might be a grounding issue since that only happens when pressing on the chip when the grounding plate below is present, of course that could be due to the absence of the soldered on plate too. Any chance someone has a screen cap of the please insert playstation format disc? Sony had a nasty habit of changing the pattern of the colorful blotches so I need a proper reference for SCPH-5500.

 

Well what's under the plate is:

GPU, CPU, Work RAM, Video RAM and BIOS.

The CD subsystem is the smaller chips. The one with a EDO RAM chip close by is the SPU (Sound hardware), the one with a SRAM close by is the CDROM data decoder and the one which is closer to the laser pickup connector is the error correction DSP.

Honestly you should had not touched the plate. But since you did it already, then just hot air the chips around a bit so the graphic glitch is solved.

The PS1 board need to be treated gently. It's very fragile...

 

Okay, front and back of the motherboard. What the should I have to check??
And which are these chips that read the "bootcode" of the discs?
http://imageshack.us/photo/my-images/211/img20120917120003.jpg/
http://imageshack.us/photo/my-images/89/img20120917120035.jpg/

EDIT: btw, I've tried pressing all the chips(one by one) on the front and back of the motherboard while loading a disc but the game wasn't booting anyway.

 

Your board need attention of a specialist, sadly D:

 

Okay, but you told us to gently press the big chips near the CD section, can you tell me which ones are exactly by looking at the photos?
Thanks.

 

I just found a BIG clue to the problem on mine, the voltage to the spindle motor is too low. I found a way to test this reliably.
1: Power on without a CD and shut it off (we need the laser in the center)
2: Open the cover and disconnect the 4pin motor cable from the drive, leave the laser connected.
3: Plug the lid switch and place an Audio CD on the drive
4: Now probe the power pins, (the white wire and the grey one next to it) and power the system on
5:Wait for a second or 2 and you should get a long, stable reading.
6: My bad unit reads 4.46V, my good units all read about 4.53 regardless of the model.

 

hey you have to replace all three pots with new ones thats the only way to restore it and never touch pots more than one time it will get loose hence loosing resistance..... verymuch delicate..!!! aahh..!!!
and use an appropriate iron to solder it or you will melt your new pot also.!!! and last thing if want to play with hardware scph 1000 to scph 5903 are best .and if you want to play games SCPH750x.SCPH900x and
SCPH100 are the good ones.and finally PSX AND PS 1 machines are nastiest in gaming history because they were developed hastily by night...!! fighting with nintendo reead playstation historyyou will get the information. :victorious:

 

Okay, sorry to post in this old thread but only recently I've noticed that the plastic is melted in the section that I marked in the photo, also the resistance(474) nearby the capacitor seems to have a melted point...? Could this be the problem the console is not reading any game disc at all??

 

I wouldn't have thought so - I think those caps are the ones that couple the output from the RF amp chip into the CD DSP - so if they were open it wouldn't read anything including audio CDs.

 

Do you think that the problem could be this one? https://www.assemblergames.com/foru...-fuses-on-a-SCPH-1001-Playstation-motherboard
I've got to test those fuses.

 

No, none of them would cause the problem you're having - you clearly have power to the CD drive or you wouldn't be able to play audio CDs.

The closest I've ever seen to that was a console that wouldn't switch to x2 mode correctly - and that was the Rohm chip.

 

And where is this chip?

 

On the PU-8, it's on the back of the board next to the CXA1782 - I can't remember the exact part number (and it varies between board revisions), but it starts with "BA" - it's also quite distinctive because the middle pins are all connected together into a tab that 's soldered onto the PCB as a heatsink.