Hi, thought I would ask this here as this site has the most knowledgeable people in legacy consoles. I recently built my own Pic flasher and flashed my first pic chip (yey!). I flashed MM3 hex to a 12f629 pic in the hope of chipping my old ps1 9002 model. All seemed to go well. When I booted it after installing the chip, I get no picture or sound. The green light comes on the psu, which suggests the psu is still sound, the screen flickers briefly which suggests the AV signal is initiated but not picture/ sound or CD rom activity. This points me to a problem with either an IC or associated component. I have removed all wires and soldering but still same problem. I have modding/ soldering experience and my soldering is ok so I'm a bit stumped. Has anyone else come across this problem when installing stealth chips on psx models? Any help, suggestions greatly appreciated. [GALLERY=media, 93]Image by Taijigamer2 posted Jun 30, 2015 at 8:56 AM[/GALLERY][GALLERY=media, 92]Image by Taijigamer2 posted Jun 30, 2015 at 8:55 AM[/GALLERY]
I can't see the photos (most likely because you didn't set them to public) - but my guess is that you accidentally shorted a power rail and blew one on the on-board fuses.
Trimesh u legend! I don't know why I didn't think of that. I know my way round an xbox 360 motherboard like the back of my hand but I'm new to the psx board. I have amended the photo privacy settings, thanks for the heads up. Do u know where the safety fuses are on the pu-23 board?
Sorry I didn't elaborate, I mentioned it in my 'intro' thread. It is a pcb of my design that I based on the JDM programmer schematic. [GALLERY=media, 91]Image by Taijigamer2 posted Jun 30, 2015 at 8:54 AM[/GALLERY] I got it made by OshPark, they send out 3 of every board so I still have 2 untouched pcbs if people want one. I've also got the Eagle files if people want to modify or improve it. Electronics isn't my first passion so there is probably plenty of room for improvement
They are right next to the power input connector - they are marked "PS60x" on the silkscren and have numbers like "15" or "20" on top - you can replace them with regular SMT fuses (20 = 1A, 15 = 700mA). Nice install, though.
Thanks. I was happy with this install, imagine my disappointment when there was no picture or sound, especially after some of the 'car crashes' I've seen that work. I will try those fuses tonight, hopefully that will get it up and running again. Thanks for all the info.
No problem - just in case it helps, I've recorded the voltages I got on the SCPH-9002 I have here - obviously yours won't be exactly the same, but it should be close.
Ok, checking the voltages, my values are practically the same except for the PS604 fuse which gives a value of 0.97V. I'm assuming the .5G fuse has a rating of 500mA? This is hopefully the reason why it fails to boot.
It's actually 2A - that's the main 3.5V supply to the core logic, so if that's out it would certainly explain why you weren't getting any output.
Thanks for the info. I couldn't work it out from the markings. Do you have a schematic of the psx motherboard, your knowledge is impressive. That would explain why the psx failed to boot. At 0.97v that would clearly not be enough to drive 3.5v ICs. I will desolder it and replace with a 1206 2A fuse. Hopefully that will get it going, then I will have to reinstall the mm3 chip .
I've just spent way too much time looking at these machines back in the day - but as it happens, the SCPH-900x series does have a complete service manual (including all the schematics) available - there is a copy for download here, for example: http://gamesx.com/wiki/lib/exe/fetch.php?media=schematics:service_manual_scph_9000_3rd_ed.pdf Note that this might not exactly match your board, but it should be pretty close.
Thanks TriMesh, that worked a treat. That service manual really helped as well. Replaced blown fuse (PS604) with a new 2A 6V smd fuse (0805 or 1206) and it booted straight up no issues. Had to rearrange wiring slightly due to using an MM2.x diagram for a chip with MM3 hex flashed to it. Now kicking back to a game of FFVIII, anti stealth circumvented, ah, nostalgia.
