Mainboard fault ? Analog stick

[price351]

After doing a few repairs on psp's I have noticed that some mainboards are now having problems with the analog functions (its keeps pressing down) the consoles have been stripped and the parts tested one by one, it's turns out that the fault is on the board. It's odd because only the lcd was replaced, why should this affect the analog board functions ?

It's happened several times and all were jap psp-1000's, any ideas would be apperciated.

[msanchez]

I have the exact same problem, after changing my LCD. So buying a replacement analog assembly won't help? I have a US psp though, first wave launch. I hope it's not my mobo, since I doubt I'm going to find a TA-79 board cheap or from someplace I can trust. Let me know how your doing on this and steps you've taken to fix the problem.

[nope]

have you lost the small see through peice of rubber that connect the nub to the mainboard???

[msanchez]

It's still there, after messing around with it a bit more I got the analog working fine. However it has another issue, basically when I press home while playing a game/homebrew/pops the psp action buttons and d-pad are not responding. They are staying mapped to the game so if I press one of those buttons instead of doing the action on the home menu, it does it inside the game.

I can use the volume up/down, brightness and in UMDs and homebrew I can also use the home button on the home menu, if I press home on the pops home menu it doesn't do anything.

I've done my fair bit of reading on this on the forums and all I can find is what you mentioned, the little rubber, yet nobody reports back on whether that fixed their problems or not. I'm probably going to buy the damn assembly and try it out, but I want to do some research first so I don't end up buying it with 0% chance of fixing my problem.

Thanks for the suggestion though, :D if you happen to think of anything else let me know since I won't be ordering it for a few weeks in any case.......... first the screen now this...... I'm going to need a punching bag if replacing that thing doesn't work or else I fear for the poor little psp.

[hoodlikegaza]

Im having this exact issue now as well. After replacing the lcd in my 1001 usa psp, the analog controller stopped working. Ive tried buying a new analog stick, and even replaced the rubber piece that interfaces with the mainboard, but it still doesn't work. Does anyone have any idea how to fix this?

[Squirrel61]

I've come across this issue a few times and everytime cleaning the clear rubber strip made the nub behave normal again. Don't be misled by the rubber strip being clear, its conductive rubber! A small piece of dust or other rubbish can make the nub behave strange.

Usually the rubber doesn't break, wear or get damaged otherwise. But if it gets destroyed, it should be possible to use a piece of rubber strip from an old LCD (not the PSP's, the cable is glued on that one). I saved a 4" strip from an old broken b/w LCD just in case...

[hoodlikegaza]

But i purchased a brand new strip, and it still doesnt work...

[mame-man]

Im having this exact issue now as well. After replacing the lcd in my 1001 usa psp, the analog controller stopped working. Ive tried buying a new analog stick, and even replaced the rubber piece that interfaces with the mainboard, but it still doesn't work. Does anyone have any idea how to fix this?

did you make sure the rubber strip is in the correct way around (contacts running from faceplate to board)?

[Squirrel61]

And check the contacts on the mainboard and on the nub for dirt too.

[Fuser]

I had some problems with the nub as well. I replaced my LCD then it happened also my home buttone doesnt work. All of my other buttons work fine just not my home button. I figured out tho in a series of trial and error experiments... I pushed down where the silicon/rubber contact strip was and it stopped malfunctioning. I then tightened the screws on the back and it worked fine. at least at has for the past hour anyways. Now I'm in search for what can remedy my home button problem without having to buy a new strip.

[zatara10]

i have like problem with my psp slim,analog stick not work up and down,left right work fine,i try new analog stick,problem not solved,which chip controlled analog stick ? i need psp schematic diagram ? please help

[Squirrel61]

There is no PSP schematic diagram for any model. You should check the conductive rubber and the contacts on the motherboard for dirt. For the slim, you have to remove the motherboard for this, since the contacts and the rubber are on the underside.

[msanchez]

i have like problem with my psp slim,analog stick not work up and down,left right work fine,i try new analog stick,problem not solved,which chip controlled analog stick ? i need psp schematic diagram ? please help

Did you recently open up your psp? If so, press the bottom left side of the handheld (where the analgo nub is) between your fingers and check and see if it works fine while you're pressing. If it does, your screws might not be tight enough. If it doesn't, the do as Squirrel61 suggested and check your rubber.

[zatara10]

this is not analog stick and silikon rubber problem...i find the problem.remove SCEI 742KU63 ic,analog stick ways go this ic,this ic send voltage to analog stick,voltage returned from analog stick,742KU63 ic process this signal and send CPU.ic is defective :( i need this ic

notice : i m GSM Electronic Technician ;)

[msanchez]

this is not analog stick and silikon rubber problem...i find the problem.remove SCEI 742KU63 ic,analog stick ways go this ic,this ic send voltage to analog stick,voltage returned from analog stick,742KU63 ic process this signal and send CPU.ic is defective :( i need this ic

notice : i m GSM Electronic Technician ;)

Well that's a tough one then. I've never seen actual electrical problems with a psp yet. It's not like I could easily diagnose such issues, but the 4 (maybe 5) I've attempted to fix (3 with the same analog problem) were either because of the rubber being put on wrong, or the case not being tight screwed on tight enough.

I wouldn't even begin to know where to get the part you're looking for.

[zatara10]

I'm sure for the stick is right.The stick's connecting to the mainbord's silicon conductive is right.

And after I disebled the silicon consuctive and I soldered the new stick to main board with 4 cable.But the problem not yet solved. In other words The problem isn't connection of the stick and mainboard.


And I maked some measures and the result is:

An integrated is controling movement between stick and main board. So I understood this integrated have broken.In the same time I found that:
there is a memory battery near the integrated.It is empty because of shortchange.


How I find this SCEI 742KU63 ic ? or TA-085 mainboard ?

notice : thanks my friends Fatal for english translation

[grnflme]

But i purchased a brand new strip, and it still doesnt work...

Where????????!!!!!!

i srewed mine up and need a new one i went to best buy and the staff there had no idea that little thing existed...dumbasses.....

[msanchez]

Where????????!!!!!!

i srewed mine up and need a new one i went to best buy and the staff there had no idea that little thing existed...dumbasses.....

I bought one from a site called richpsxparts or something similar. Do a search for it, it was fairly popular so it should still be around.