Forum

2017 PSP Project  

Page 2 / 2 Prev
  RSS

rutledge.allen.l
Eminent Member
Joined: 3 months  ago
Posts: 39
02/02/2017 3:02 am  

No worries, I still got a few hrs at work. Went ahead and ordered the new power module, I think I might have messed it up popping off the clips. I am going to borrow the fiancee's hair dryer and pull it apart tonight and see if there is anything I missed or did wrong. 

Edited: 2 months  ago

ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
02/02/2017 3:17 am  

This is what I'm gathering so far. I drew lines to show the path of the power. I'm still making the assumption that it's dropping to 5v, not 3v.

It doesn't actually drop to 5v until after the inductor (the component labeled 101 that sits above the 8-pin chip) during normal use. If I had one of these in my hand, I would hook 12v to it so I could see normal operation and verify voltages. 

If it is indeed dropping to 5v, then it appears that Pin 3 is the pin to hook to. You can also attach after the inductor and to the component with the 0 on it. I'm still not 100% sure on this, maybe 90%


ReplyQuote
rutledge.allen.l
Eminent Member
Joined: 3 months  ago
Posts: 39
02/02/2017 4:02 am  

"component with the 0" the 220 vt one?


ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
02/02/2017 4:16 am  

Yep. At the end of the red line I drew. That whole thick trace appears to be a good connection point. If either of you guys has a 12v power source you can test the LCD with, it would tell us for sure whether it reduces to 5v.

If you do try the 12v, then you have to connect a ground wire from the Pi to the GND on the LCD controller. If you don't, then the composite video won't work.


ReplyQuote
rutledge.allen.l
Eminent Member
Joined: 3 months  ago
Posts: 39
02/02/2017 9:48 am  

I think I know why the power module is not working. Looks.like like a short like you said. I went ahead and ordered the new one. The hair dryer worked really well taking it all apart ;)


ReplyQuote
rutledge.allen.l
Eminent Member
Joined: 3 months  ago
Posts: 39
02/02/2017 1:25 pm  

Calling it a night. No go on this screen. I wired a hot wire to Pin 2 and then tried 3. At 2 I get 0 going past that. On pin 3 I read 5v out to the fpc (can't find anything in the plastic past that) but no power up on the screen . did alot of Googleing and no dice. Once someone gets one and confirms it is useable, I'll order one of those.


ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
02/02/2017 6:05 pm  
Posted by: rutledge.allen.l

 

Calling it a night. No go on this screen. I wired a hot wire to Pin 2 and then tried 3. At 2 I get 0 going past that. On pin 3 I read 5v out to the fpc (can't find anything in the plastic past that) but no power up on the screen . did alot of Googleing and no dice. Once someone gets one and confirms it is useable, I'll order one of those.

   

This is why I can't stock LCDs. Every order surprises me with something different. I've got a bunch of these arriving any day now, and I expect to get the same thing. Once I get it and remove some components I'll probably be able to find a solution.

On the power module, have you tried cleaning up the solder and soldering up the battery and power inputs to see whether you get anything? These are pretty resilient.


ReplyQuote
rutledge.allen.l
Eminent Member
Joined: 3 months  ago
Posts: 39
02/02/2017 7:44 pm  

Tried to clean it. No luck. Going to grab some wick from Frys tonight and give it abother shot.


ReplyQuote
trickluvdakid
Active Member
Joined: 3 months  ago
Posts: 15
02/02/2017 8:52 pm  

Did some continuity checks, and I agree with your drawing.

Removing the buck and jumper pin 2 > pin 3 looks correct.

Working on this right now, will post pictures when completed.


ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
02/02/2017 8:59 pm  
Posted by: trickluvdakid

 

Did some continuity checks, and I agree with your drawing.

Removing the buck and jumper pin 2 > pin 3 looks correct.

Working on this right now, will post pictures when completed.

   

Any chance you can try 12v on the power input first?


ReplyQuote
trickluvdakid
Active Member
Joined: 3 months  ago
Posts: 15
02/02/2017 9:26 pm  

Did not try.

Removed the buck and there is continuity from pin 2/3 to the resistor.

Will hook up to 5V after lunch to verify.


ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
02/02/2017 9:31 pm  
Posted by: trickluvdakid

 

Did not try.

Removed the buck and there is continuity from pin 2/3 to the resistor.

Will hook up to 5V after lunch to verify.

   

That's some good looking work. I asked about testing it first because I can't be 100% sure it's dropping to 5v. It should be 5v, because there is a second buck converter up top that should be knocking it down to 3.3v. 


ReplyQuote
trickluvdakid
Active Member
Joined: 3 months  ago
Posts: 15
02/02/2017 10:18 pm  

Thanks, helps to have the right tools.  Should've used wire to bridge it, but solder works too.

OK...so... Setting my power supply at 5V resulted in 4.2V at the resistor.  To get 5V at the resistor, I set the power supply at 5.75V.

Edited: 2 months  ago

ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
02/02/2017 10:25 pm  

You might be getting a voltage drop across the inductor. Whats the voltage at the pin2/3 bridge?


ReplyQuote
trickluvdakid
Active Member
Joined: 3 months  ago
Posts: 15
03/02/2017 12:38 am  

There was a 0.7V drop across the diode.

I removed the diode, bridged it, and I now have 5V from the input to the resistor.

Not having the diode shouldn't be an issue.  But I know it's there for a reason...


ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
03/02/2017 12:44 am  

It's probably a leftover from a previous version of the board. Most of the cheap buck converters use a diode in their function. This buck doesn't need it, so I can't tell you why they left it. On a related note, there is also a capacitor and inductor on the input of the chip that don't appear to be doing anything.


ReplyQuote
trickluvdakid
Active Member
Joined: 3 months  ago
Posts: 15
03/02/2017 12:51 am  

Thanks for the help.

I'll get a good start on this Saturday.


ReplyQuote
rutledge.allen.l
Eminent Member
Joined: 3 months  ago
Posts: 39
03/02/2017 2:23 am  

Cool. let me know how it comes out. If all else fails I saw Fry's has 4.3" LCD back up cams so could grab one of those and give it shot. 


ReplyQuote
trickluvdakid
Active Member
Joined: 3 months  ago
Posts: 15
05/02/2017 12:00 am  

Started my project, but ran into a roadblock.  Need to order a new audio jack.  The teardown PSP I was using, the audio was crackling.  So, I ordered a new part.  Will start again later in the week (hopefully by Thursday).  But, so far so good.

Question for anyone ... when I tore down the PSP I had, I couldn't find this...  http://www.ebay.com/itm/Original-Joystick-Rubber-Contact-Button-Replacement-Parts-For-PSP-1000-Fat-/262278863185?hash=item3d1109d951:g:lSQAAMXQDrJRzA2h

Anyone have any idea?  Or a picture where it would be located?


ReplyQuote
rutledge.allen.l
Eminent Member
Joined: 3 months  ago
Posts: 39
05/02/2017 12:22 pm  

 got another screen. Doesn't appear to be plug and play. Which converter gets pulled?


ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
05/02/2017 6:56 pm  
Posted by: rutledge.allen.l

 

 got another screen. Doesn't appear to be plug and play. Which converter gets pulled?

   

I think your image got deleted. I'm not seeing it.

Posted by: trickluvdakid

 

Started my project, but ran into a roadblock.  Need to order a new audio jack.  The teardown PSP I was using, the audio was crackling.  So, I ordered a new part.  Will start again later in the week (hopefully by Thursday).  But, so far so good.

Question for anyone ... when I tore down the PSP I had, I couldn't find this...  http://www.ebay.com/itm/Original-Joystick-Rubber-Contact-Button-Replacement-Parts-For-PSP-1000-Fat-/262278863185?hash=item3d1109d951:g:lSQAAMXQDrJRzA2h

Anyone have any idea?  Or a picture where it would be located?

   

That's the conductive pad for the joystick and sits in the left piece on the LCD bracket. It's not really needed on these mods.


ReplyQuote
rutledge.allen.l
Eminent Member
Joined: 3 months  ago
Posts: 39
05/02/2017 8:39 pm  


ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
06/02/2017 12:24 am  
Posted by: rutledge.allen.l

 

   

Buddy you can't catch a break on the LCDs. I just received a huge order of LCD (not from eBay, I'm still waiting on those) and I received this exact one. 

So here's the problem...the buck converter on these doesn't drop the voltage to 5v, it drops it directly to 3.3v. If you remove the components and hook 5v to it then you will fry everything. I'm working on a solution and Ill post it soon.

To everyone else receiving new boards...please find a way to attach 12v to them and measure the voltages coming out of the 8-pin buck converters. If these new designs have the voltage dropping to 3.3v immediately, then you will destroy your board when you attach 5v directly to the pins.


ReplyQuote
othermod
Estimable Member
Joined: 6 months  ago
Posts: 112
06/02/2017 1:34 am  

So I removed everything that's not needed anymore, except for the capacitor labeled 220. It's not needed, but an extra capacitor never hurts.

That is there the 3.3v gets attached. Where is the 3.3v coming from you ask? This little guy.

Edited: 2 months  ago

ReplyQuote
trickluvdakid
Active Member
Joined: 3 months  ago
Posts: 15
06/02/2017 10:04 pm  
 
Posted by: trickluvdakid

 

Started my project, but ran into a roadblock.  Need to order a new audio jack.  The teardown PSP I was using, the audio was crackling.  So, I ordered a new part.  Will start again later in the week (hopefully by Thursday).  But, so far so good.

Question for anyone ... when I tore down the PSP I had, I couldn't find this...  http://www.ebay.com/itm/Original-Joystick-Rubber-Contact-Button-Replacement-Parts-For-PSP-1000-Fat-/262278863185?hash=item3d1109d951:g:lSQAAMXQDrJRzA2h

Anyone have any idea?  Or a picture where it would be located?

   

That's the conductive pad for the joystick and sits in the left piece on the LCD bracket. It's not really needed on these mods.

   Thanks!


ReplyQuote
trickluvdakid
Active Member
Joined: 3 months  ago
Posts: 15
06/02/2017 10:06 pm  
Posted by: othermod

 

It's probably a leftover from a previous version of the board. Most of the cheap buck converters use a diode in their function. This buck doesn't need it, so I can't tell you why they left it. On a related note, there is also a capacitor and inductor on the input of the chip that don't appear to be doing anything.

 

   I'll leave the capacitor.  You suggest removing the inductor? Thinking it won't make a difference.


ReplyQuote
trickluvdakid
Active Member
Joined: 3 months  ago
Posts: 15
12/02/2017 11:56 pm  

Making some progress...

Adam, I seem to have lost this :

Mini Switch (the same as the original PSP Wifi switch) for switching the audio on and off (optional feature)

I don't see anywhere in your store to order another one.  Is it possible to order one from you?

 


ReplyQuote
Page 2 / 2 Prev
  
Working

Please Login or Register