PSP Mod help

[Nefarius]

Yo, I got most of my parts for my psp now so I can start modding. Among them was a 50mm 8Ohm 0.5W Speaker.
I informed about how to hook it up multiple times & also asked if it was possible for it to work with that speaker.
Got the same reply:"Yes it should work & just hook it up directly to a speaker" So thats exactly what I did.
Now my right psp is broken & probably the 50mm one too.
But thats not all, when I had put my psp ack to gether my screens backlight was broken. (problem solved, soldered my fuse together)

But can you guys enlighten me over the fact why my psp speaker mod failed miserably? I'll look further on the forums myself too.


http://shop.conrad.nl/componenten/componenten-elektromechanisch/akoestische-componenten/kleine-en-mini-luidsprekers/541336.html
This is the speaker I used.

[FOOKz™]

Ok its good you ask questions. Now, there are 2 concerns i have.

- "soldered my fuse together"
Honestly this is no permanent solution but i would do the same if i was in a hurry. But that's beside the point.

- You are paralleling TWO speakers together which Loads the amplifier in the PSP. If the Amplifier is being loaded, then it is doing too much work and usually it will quit and burn out.

8 Ohms is a measurement of resistance, which the speaker you use is 8 Ohms. Right? yep. Now if you connect two in paralell you are Decreasing the Resistance by creating TWO paths that are 8 ohms; you get half of 8 Ohms which would be 4 Ohms since there are 2 paths. So [2 paths / 8 ohms = 4 ohms]

If you create two paths then its basically like shorting a 9 volt square battery then it begins to heat up. This is the same concept for the PSP's amplifier that drives the Speakers.

Now, if you Put the speakers in series you get the same effect.

However your amplifier will work even harder since there's more resistance (16 Ohms) and that doesn't let all the audio and electricity to go through the speaker.

Sorry for the Novel i had to write LOL.

You are supposed to create an amplifier circuit to drive that speaker. I can design you a circuit because that's what i love to do. =D

[Nefarius]

Well for some weird reason that I am sure you can explain :P The speaker is working again! But if you'd want to make me a diagram sure, but keep it simple. Don't like difficult things and about the fuse... Yeah I know I need to get a new one, probably a restartable one. I'll check the forums to see which one I need ^^.

[FOOKz™]

for the record, i have never modded a PSP before. The symptoms you described is what generally what could go wrong with any piece of electronics. Yes, maybe you could find a resettable fuse i'm not sure.

[Nefarius]

Hoozah! After poking around on the forum for a while Matt pointed out a topic which helped me alot. Replaced my fuse with a resettable one now, works like a charm.

But now I have another problem. I need to know what kind of resistors I need to drive that speaker with a LM386 AMp Chip. I know you have to use Ohm's law V = I × R but thats about as far as my high school physics go. I forgot most of it >.>

I have the following dataz:
5V - Powersupply
0.5W / 1W - Power consumed by the speaker
8 Ohm - Impedance/Resistance of speaker

Update: Found an easy to built Amp for the LM386, I just don't fully understand it >.> Damn you american symbolics! http://www.techlib.com/electronics/audioamps.html#LM386
Post Merge: February 07, 2010, 02:09:38 AMAs I posted earlier I am messing about with the LM386 chip & a speaker. Well I went for broke hooked it all up using https://www.acidmods.com/forum/index.php/topic,28600.0.html this concept. I figured that its about the same concept.

Being as tired as I am considering I had 2 hrs of sleep tonight (couldn't stop thinking of how to get it to work & how to make it look good) I hooked it up.
At first it didn't work, checked my joints, 1 came loose. Alright no problem there soldered it back on and turned on my psp. I don't know what happened next, either my psp shorted out or... Well I have no other explanation. So checked my joints again, everything was fine, traces the wires, nothing there either. Turned it on again. Hoozah! It boots! But now it wont load my XMB, it just sits there and loads a bit. Won't turn off, will turn on and I can get into recovery mode. Thats it, I have no idea what happened. Disconnected the chip + speaker, still the same. Anyone have an idea?

Uptdate: Boots if I go into recovery & use the load recovery eboot.pbp. Busted the right speaker (again) Maybe it'll start working again like first....

Update #2: Doesn't boot anymore when using the Recovery Eboot.pbp

[FOOKz™]

Ok i can answer your first question

How do I calculate the Op Amp Gain?

Everything else is out of my realm. Just give me a bit to get everything written down.

EDIT:
Heres the way to calculate the LM386 OP AMP's gain:

1 + Rf / Rin

** All Voltages Are Measured in RMS to Calculate Gain

If you need an in-depth explanation and a bit of theory or physics i will help further in showing you the Db to voltage Av calculations.

Also, i forgot to add you must Add a coupling Capacitor on the inputs and the outputs so it filters out the DC voltage sorry... i'll edit that soon.

Schematic:

[Nefarius]

Awesome! Thanks FOOKz :3

And on a different note, I Semi Bricked my psp while trying to hard mod it. Don't ask me how, I have no idea. Just as I am running out of ideas of fixing it.

I tried to do it like this: http://www.makeuseof.com/tag/how-to-downgrade-your-psp-upgrade-to-a-custom-firmware-part-two/

and then I tried it like this: http://www.consolespot.net/forums/psp-news/19631-release-recover-flasher.html

And on both my psp didn't load the pandora + mms nor did it load the Eboot.pbp to get to the Flash menu to install a different CFW. I'll keep looking, but I am defo running out of ideas besides getting a new Mobo/Modchip.

Update: Flashed succesfully back to 3.71-m33, the same problem. Boots up, get a Sony logo, then freezes.

[FOOKz™]

Awesome! Thanks FOOKz :3

Your welcome. Its what I do best.

I Semi Bricked my psp while trying to hard mod it.

Cinder Block or plain red brick?

OK sorry for the smart comment but i had to say it. To the best of my knowledge you may have static electricity damaged something. Else check for loose solder or bent IC pins anywhere. If none of that helps then Seriously i have no clue at all dude.

One question... Do you have a multimeter available; or a voltmeter and ohm meter? The Meter will help a lot for troubleshooting the motherboard. The meter will give clues to what may be wrong internally with the chips. If a component is broken its replaceable, if an IC has died(not likely) then screw the PSP and get another one.

[Else Good luck soldering an SMD IC with more than 48 Pins =D] lol j/k

[Nefarius]

I'll just order a new mobo from ebay, not going to put the effort in finding the faulty 'I dunno what it could be' on my mobo. Every start is difficult, but now I can focus on different things. Like making another lm386 amp using http://www.techlib.com/electronics/audioamps.html though it seems a bit to advanced for my skills. Oh well learning the hard way has always been my style XD

Thanks for all the help, you too Tea!
Post Merge: February 09, 2010, 07:52:48 AMHmmmm.... Could anyone simplify this schematic found here:

http://www.techlib.com/electronics/graphics/LM386amp.gif

Its a bit to advanced & I doubt if I will be able to built it into my psp, but I'd like to make one just to see if it works. Otherwise I'll use the one I already made with the schematics FOOKz provided.

Found a 4pin Dipswitch and I was wondering if I could place it in that schematic where the other switch is supposed to be.

[FOOKz™]

Sure man i'll simplify it. Give me until tonight i have stuff to do.

EDIT: yerrrp the dip switch can replace the pushbutton.

[Nefarius]

If you need an in-depth explanation and a bit of theory or physics i will help further in showing you the Db to voltage Av calculations.

Fire away! Always in for some calculations, I'll write it down too! Good for when I need it.

Edit: Here's the schematic I made using teh interwebs & https://www.acidmods.com/forum/index.php/topic,29983.0.html Hawk VU Tut. Could anyone check it for me?

- The arrow is the 10k Potentiometer. (says '10k')
- The round thingie is the PNP Transistor. (says 'PN' but I missed a letter xD)
- All the blue lines going to nowhere are the 5 LEDs.

Also how can I put a Dip-Switch in that circuit to turn it on or off?

Update: Placement of the VU Chip + PNP Transistor
Post Merge: February 12, 2010, 10:37:50 AMAnother thing I wanted to do was add 2 extra psp speakers. Well.... Here they are! Not hooked up yet as this is a prototype, but its awesome!

In order to get them to fit I had to dremel :censored:loads of plastic & had to solder a lug to one of the speaker in order to still use the screw hole + (a different) screw.

Check it out!

[FOOKz™]

Then i have to calibrate the 386's impedance output specified to the speaker's impedance input.

[Nefarius]

Well gotten my used 1004 in the mail today! And now I have a working psp again w00t! But I did had some difficulties with it. For instance when I placed the 1004 innards into the 1000 shell it didn't work. When I placed it back into the 1004 shell it did work. I have no idea how this happens, but meh don't really care tbh. I do need a new PSP1000 Screen though, all that messing around with it kinda screwed it over. Oh well, the good news is I have a working psp again!

Edit: Oh FFS!!!! Again I have the same problem, now on my new mobo! =< and I didn;t even do anything to it! Could it be my screen which is interfering with something? Or could it be the 50mm speaker...?

*hits himself with a brick* I never should've started hardmodding QQ