Hardware Repairing UMD chip on psp 2000's motherboard

[giovany86]

Hello everyone, i got a psp 2004 (Slim & Lite not Brite) and this psp has a little problem.
When i press the bottom left corner of the screen, the umd drive start "working" by itself (even if it's empty) or stop "working"
The problem is from the motherboard itself, i've already replaced the drive with a brand new and tested it on my second psp 2004 (before i sold it)
So, now, i've got a hot air station and i'm looking for some help to fix this motherboard (because i've modded the nand original XMB theme with one i've made myself)
This psp is a DATE CODE 8B and the serial is HC6141317.

If anyone got some infos on wich chip to replace, it would be really nice to help
Sorry for my bad english and i've a lot of dead psp 2000's motherboard so i can take the chip off a dead mobo to replace the one that is defective x)

edit : here is a picture of what is displayed when i close the umd tray, sometimes nothing show up unless i press the famous bottom left corner of the screen (actually where my finger is)

Spoiler: picture :D

 

[FAST6191]

If pressure on the screen (and thus board) causes such behaviours it is typically a crack in the board somewhere or a crack in a solder joint in the stress line.

I am not familiar enough with this model to know if there is any documented list of things to check but it should not be too much hassle to check and reflow things. If it is a PCB crack then fixing multi layer boards like this is a nightmare and I would probably source a new board instead.

 

[giovany86]

Ah well i hope it's just a solder crack x) i don't know where to check for that on the board :/

 

[giovany86]

Hey there are some update :
- i managed to fix the problem of the bottom left corner of the screen
- i think i've found what chip is defective
- here are some pics

Spoiler: The chip who's defective

And now i'm looking for this chip, i don't know where i can get a brand new / used one but working x)
ps : on all my broken motherboard, this chip is not present or not the same at all (i used these broken board to train myself with my new equipment few month ago)

 

[FAST6191]

Assuming it is the Sony chip are are referring to and it is not a reflow job then it sounds like you have encountered different hardware revisions. Always fun.

Bonus here is that appears to be a custom Sony chip rather than something they might sell for general purpose. You can try searching for the numbers on the chip ( https://octopart.com/ https://www.findchips.com/ the big component vendors, aliexpress, plain old search engine, try them all) but if it is custom Sony and not something people care about normally then I doubt it will be here either.

Also if you go diagonally from the Y in Sony on that chip there looks like what could be a missing component. It is possible to have unpopulated sections of a board (almost all boards will have some, indeed next to one of the connectors on that image there appear to be a bunch) but the appearance and colour of that does not look like a simple unpopulated section.
At the same time unless it was being shorted out I don't know why pressing on the edge would make it come good or cause the behaviours you describe if it was a missing component, maybe if it was loose and has since fallen off when you took it apart and pressing it made a circuit where there was not one. If that is the case then find out what it was and replace it. In a position like that it is either going to be a resistor/fuse, capacitor or ferrite bead. Looking at what I can see on https://www.ifixit.com/Guide/PSP+2000+Logic+Board+Replacement/1272 it is a brown band device, which is typically a capacitor. No idea what value though.

Anyway if it is going to be a hard to find chip then it is at this point most would probably unplug the motor/loader so it does not make a sound and go pure software hack.