www.theoldcomputer.com

what you need:
------------------
NES
ps1 round screen
battery pack at least 7.5v
controller
a dremel
stuff to make a new case (acrylic aluminum etc)
lots of wires
phillips screwdriver
pliers
soldering iron
desoldering iron


which battery:
-----------------
NiMH or Li-ion
if you want to choose NiMH, then you don't have to do much for them.they are cheap, and to charge them, you just feed power straight to them.unfortunately, they are often heavy and big

Li-ion batteries are great, but require a bit of work.they need special charge protection circuits.they cannot be shorted or overheated.despite these things, they are very worthwhile.they are small, thin, lightweight, and long-lasting.the bad part is that they cost quite a bit


WARNING : If you do not have a charge protection circuit, Li-ion batteries will EXPLODE.these batteries are dangerous if not used properly.they may not be shorted, overcharged, or undercharged.if you are buying Li-ion batteries from eBay, you MUST buy a Universal Battery pack.these battery packs have their own built-in charge protection circuits and often have charge indicator LEDs.if you do not know much about Li-ion batteries and their various protection circuits, then you MUST use NiCD

the more mAh a battery has the longer the NES will stay on


for signals and low-power applications, IDE cable works great.it's 28 AWG and can be found in many old computers.it shouldn't be used for high-current situations
for most power lines, you should use at least 20 AWG

test the setup:
------------------
hook everything up without modifying anything.(use alligator clips to test battery)
if the battery is more than 8.5v it will fry the screen.if it is build a power regulator first.that is will come later in the page.

disassemble the system:
------------------------------
phillips screwdriver
NES

flip the NES over and remove the 6 screws on the bottom and the 2 for the controller ports

flip it back over, remove the top, and take out the 5 screws holding the shielding in

take the shielding off, and unscrew the 6 screws holding the cartridge mechanism in

remove the cartridge mechanism (you may have to slide it forward a bit) and take out the 2 screws near the RF box in the upper right corner

unplug the two player ports and the power/reset plug
pull out the NES board


removing the rf box:
-------------------------
pliers
soldering iron
desoldering iron

the rf box takes the composite signal from the NES and turns it into rf.it also takes the 9v from the external adapter and turns it into 5v.it is much too big, so we are going to take it off.if you hook up power, then you will notice that the NES does not respond to the power button it is just constantly on.that is normal, so don't worry

start by desoldering the four tabs.obviously you won't be able to fit your desoldering iron over the whole thing, so you have to suck up as much solder as you can from the sides of the tabs
desolder the 5 pins
flip the NES board over and take off the cover of the rf box


find the regulator and desolder it.the regulator looks like a small black box with 3 pins and a metal tab at the top.we need the regulator to bring down the voltage of the batteries so it is safe for the NES board

taking out the board:
-------------------------

grab your pliers and start breaking off pieces of the board
bend the walls until they break off the board
using your soldering iron, take out the pins, if there are any left still in
grab the part that is sticking out and pull, while heating the other end with your soldering iron
you should now have all parts of the rf box taken off
make sure you save the 7805 regulator and the heatsink that is attached to it

Lovin the post. Could you also post the original link to where you found this from.
Pardon me though if you wrote this yourself. =]

what you need:
------------------
desoldering iron
soldering iron
IDE cable
small flathead screwdriver
needle-nosed pliers
72 pin 0.1" spacing card-edge connector
soldering iron

making the board thinner:
--------------------------------
there are a lot of capacitors sticking up on the board.these need to be flattened.all the ceramic capacitors (the brown disks) can just be bent over.the electrolyic capacitors (the cylindrical ones that look like cans) cannot be, so we must relocate them
relocating capacitors is an easy task, but can be quite boring.luckily, the NES only has 3.
this is really easy to do
first desolder the capacitors
get some small pieces of IDE cable and strip the ends
solder them to the capacitors, then to the NES board.make sure you get the polarity right, or your NES will not work
use a small dab of hot glue to hold them on the board
you can do this operation for any system with large capacitors.it is almost essential if you want a decently thin portable


the NES has a useless expansion slot on the bottom of it.this was never developed further, and serves no purpose on our board.time to take it off
find the expansion slot.if you need help with this, then you probably shouldn't be attempting this project
find the four metal tabs on the side of the slot.bend them out with a small flathead screwdriver
bend the metal shielding away from the plastic and remove it
snap off the outer layers of plastic with your needle-nosed pliers, being careful not to harm the NES board
grab the metal pins and the plastic with your pliers and snap the plastic off
bend the metal pins until they snap off
take the small flathead screwdriver and use it to pry up the remaining plastic and reveal the pins underneath
bend those pins until they snap off, and you are finished










if there are any more big things that can be removed, then do so. In the case of the NES, the largest remaining part on the board that we can remove is the power/reset plug.this is an easy step, simply desolder the connector.on other systems, there may be other things that need to be removed, like controller ports, power plugs, video plugs, etc.remove those things to make the board as small as possible.




add the cartridge connector:
-----------------------------------
72 pin 0.1" spacing card-edge connector
soldering iron

if you want to keep the original cartridge connector, you may do so
you need to get a connector that has 72 pins and 0.1" spacing
take the connector and press the pins close together so that they grip the NES board when you slide it on
simply, start soldering.this doesn't take long.apply iron.add solder.repeat
the soldered connector is very strong, and shouldn't need any support






relocatingthe cartridge connector: (optional)
-------------------------------------------------------
soldering iron
lots of wire
wire stripper
72 pin connector (link in previous step)
plenty of patience

if you want to put the cartridge connector somewhere other that at the top of the NES board, you need to do what is called "relocating" itthis is where you extend the slot by soldering wires to all the connections on the NES and to the cartridge slot
you need 72 wires (IDE cable works great for relocations) for this.strip both ends of all the wires and tin them.tin the contacts on the NES board and on the connector
then, start soldering the wires to the NES and to the connector.simply make sure you correspond the right contacts.just look at the soldered connector in the previous step and pretend to pull it away from the board. make sure you double check your wires when you're don't and make sure they're no longer that 6 inches

add the video amp:
-----------------------
2N4401 amplifying transistor
33ohm resistor (orange-orange-black-gold)
220ohm Resistor (red-red-brown-gold)
soldering iron

the rf box did more than just turn the composite to rf.it also amplified the video signal.when we took it off, the video signal became weak.we need to build a small video amp to boost the signal

soldering the amp together:
---------------------------------
solder one end of the 33ohm resistor to the base of the transistor
solder the 220ohm resistor to the other end of the 33ohm resistor
that point is your video out
we will connect that to the screen later

This is my type of post. Loving this. Are you planning more of these? Should we start a Retro Modding forum?

Fantastic post, a couple of my grandsons want to do this one, Keep them coming, this is the kind of stuff that I can sink my teeth into, and chew the hell out of it. Thanks!!!!!!!!

sisabling the lockout chip:
------------------------------
soldering iron
small screwdriver
piece of wire

the lockout chip in the NES was included to prevent pirated games from running in the console.it is also the reason that you get the blinking screen.if the console's lockout chip and the cartridge's lockout chip don't communicate, then the game won't play.half the time, it's not because of dirty contacts.the games would run fine if it weren't for the lockout chips.disabling it means a much higher success rate

to disable the lockout chip on the NES, first locate the actual chip.it is close to where we soldered the video amp, and it is labeled 3193A

make sure the board is the same as the picture and take the 4th pin
you need to pull up pin 4 of the lockout chip
taking the whole chip out won't work, because it is connected to the reset line, and the console won't run without it.instead, find pin 4 of the chip
put the small screwdriver under the pin to kind of pull it out of the hole
at the same time, heat the lead from the other side of the board with your soldering iron
pull the pin out so it's not connected to the board



you could be done right there.the lockout chip is disabled right now, but it is still a good idea to connect the pin to ground.take your piece of wire and solder one end to the pin you pulled up, and the other end to the silver grounding strip going all around the board

build the power regulator:
--------------------------------
soldering Iron
medium-sized piece of perfboard
7805 regulator (from the rf box)
heatsink (you can use the one from the rf box if you like)
1,000uf capacitor
two 0.1uf capacitors
1 - 10uf capacitor
1N4001 diode

before we start, you have to understand what a regulator is and what it does
a regulator takes any voltage above a certain amount and drops it to a specified voltage
for example, the 7805 regulator we are using takes anything from 7.5 - 36 volts and drops it to 5v, which is what we need for the NES
the extra energy is given off as heat, so you need something called a heatsink.a heatsink attaches to the regulator and dissipates the heat coming from it.without a heatsink, the regulator would burn itself out
the more surface area a heatsink has, the better it takes heat away from the regulator
you can use the one from the RF box
Note: A 7805 needs at least 7.5v to run, so you must make sure your batteries are at least that much

THERE WILL BE LESS PICTURES AFTER THIS POINT CUZ SOMETHING IS WRONG WITH THE SITE OR MY COMP GO HERE AND REGISTER TO SEE THE PICS



From left to right: 5v out,voltage in,and ground

it has a drawing of the regulator and its pins.pin 1 is the voltage in,pin 3 is ground,and pin 2 is five volts out

the reason for all the capacitors is to smooth out any ripples in the voltage coming from the batteries. C1 can be anything from 250uf to 1,000uf, and smooths the voltage coming straight from the battery.i just used what I had lying around, which was a 250uf cap. C2, C3, and C4 smooth out the current coming from the regulator

some capacitors can probably be excluded, like C1 (1,000uF) and C4 (.1uF).also, C1 could be around 470uF as well. the values aren't all that critical

optional
------------
the diode, D1, is not necessary.it is only there to drop the voltage by about 1v because I found that the regulator really gave out 6v.the NES will be fine running at 6v but I just wanted to be safe

i used a 3-pin connector for my regulator board because I wanted it to be removable.you don't have to, but it does make things easier


testing the board
--------------------
you can finally test your NES.solder the output pin on your regulator(+5v out)to the 5v in on the NES and attach ground.use a couple of alligator clips to hook it up to a tv.plug in a cartridge(make sure its facing the right way)add the battery and try it out.if it doesnt work dont worry.try switching the alligator clips for video and ground.if it still doesnt work check all your connections.make sure there are no shorts anywhere.it is highly unlikely you fried your NES.once you get it working set it aside and get out the screen you ordered

taking apart the screen

what you need:
small flathead screwdriver
small phillips screwdriver

the PS1 screen takes a max of 9v if your batteries are more than 9v, DO NOT hook up the screen YOU WILL FRY IT
complete the next step and then come back to this one


with the NES finally done its time to start work on the screen beginning with disassembling it

taking the case apart
--------------------------
there are 9 screws you need to take out


unscrew the three visible ones on the bottom
there are two rubber plugs at the top of the screen
pry those up and remove the screws beneath them
lift up the speaker covers and take out the four screws hiding underneath

flip the screen over and take off the back cover
you can test the screen now if you wish
BE CAREFUL NOT TO TOUCH THE TRANSFORMER AT THE TOP
its the little white rectangle with copper wire wrapped around it.a very high voltage comes out of it, so be careful not to touch anything in that top section.you'll be fine when the screen isn't plugged in, though

taking the screen out
---------------------------
there are 4 screws sort of in the corners of the board
unscrew those
snap the speakers out
gently flip the screen over onto your hand
set it down
you can test it again now if you want.make sure the metal around the screen is touching the contacts underneath the tabs

If Your Batteries are More Than 9v

what you need
soldering iron
7805 regulator
470ohm resistor
220ohm resistor


dont hook up the screen just yet we need to build a small regulator for the screen
you can use a 7805 to get 8v, or you can use a 7808.a 7808 is just like a 7805, but it gives out 8v instead. using a 7805 is much more convenient in my opinion, because you can easily find them in old electronics.if you want to know how this works, then check the last paragraph

the PS1 screen can handle from 6.89v to 8.5v.it should get 7.5v, but as long as you have a decent 7805, youll get the voltage you need.as always, test the output voltage before hooking it up



building the regulator
-------------------------
to build the regulator just solder the 220ohm resistor to the ground(middle)pin of the regulator
that will be your ground which you must connect to the screens ground too
solder the 470ohm resistor to the ground pin of the regulator BEFORE the other resistor
solder the other end to the output pin and that is your 8v out which you will connect to the blue wire of the screen in the next step
just like the NES regulator its a good idea to put a small heatsink on this one too
solder the negative lead of your batteries to the ground spot on the regulator
in a couple steps you will solder the 8v out connection to your screen
for now, just leave the V+ input and 8v out wires disconnected

how it works
---------------
This works because it is essentially a LM317T regulator, but with a higher output voltage. The LM317T is an adjustable voltage regulator. It can output anything from 1.5 to 12v with a 15v input source. All you need is two resistors. You hook them up in the same way as below, except you would choose different resistor values for different voltages. So why does the 7805 work for this purpose? Because the LM317T is simply a fixed 1.25v regulator. Experimenters rarely use anything below 5v, so a 7805 can do the job as well


add video and audio wires

what you need:
hot glue gun
soldering iron
IDE cable or other wire


once you have unscrewed the screen and tested it
you need to add the audio and video wires
unplug the two connectors at the bottom
you only need to keep the left one
we'll use that for power later


soldering the a/v wires
-----------------------------
flip the screen to the back and find the small pads near the bottom-left that say
EXT_V, EXT_R, EXT_L, HP_L, HPS and HP_R
EXT_V is where you solder the video wire
EXT_R is right audio
EXT_L is left audio
for the NES you can short the L and R on the screen because the NES is mono

shorting the headphone wires
-----------------------------------
if you tried to test it at this point
you would notice that there is no sound
you need to short together HP_L, HPS, and HP_R
otherwise the screen thinks headphones are plugged in
if you want headphones on your portable, do not short those three pads and use the headphone jack that was included with the screen

once you soldered the wires, put some hot glue on them so they don't come loose

connecting power and a/v wires and troubleshooting

what you need:
wire cutters
soldering iron
heat shrink tubing
heat gun or some heat source for heat shrink tubing
IDE cable or other suitable wire

wiring power
-----------------
take the connector you saved and find the two wires all the way to the left
those are your power wires
the blue one is positive
chop off the rest of the wires and solder a red wire to the blue one and a black one to the white one
to test the screen, simply attach the red wire to the positive end of your power supply and the black one to the negative side of your batteries
the screens light should turn on
if not, see the last paragraph
you may have switched your connections and blown a fuse

attach the regulator
-------------------------
if you had to build the regulator for the screen don't attach power just yet
solder the 8v out wire from the regulator to the red wire of your screen
solder the black wire to the ground spot of your batteries which should also be connected to the ground on the regulator
touch the positive wire from your batteries to the V+ in on your regulator, and the screen should light up
if not, check the last paragraph in this step

a/v on the nes
-------------------
once you are sure the screen works fine
solder the audio and video wires to the appropriate spots on your NES board
the audio wire just gets soldered straight to the pad on the NES board
but the video wire has to be attached to the amplifier we built
solder it to the video out wire on the amp
see the picture if you need help


CHECKLIST
before turning everything on, do a couple checks first
are the consoles ground and the screens ground tied together?they must be, or nothing will work.the screen and the console must share a common ground
is the NES's regulator board working?is it connected to the NES?
is the screen's regulator working and is it connected to the screen?
are the screen's power wires reversed? Make sure they are not
are audio and video wires soldered to the correct spots?

once you are sure of these things, go ahead and put in a cartridge
(make sure it is facing the right way.if you used the connector I did,the label should be facing up,and so should all the NES's electronics)
and attach the power wires of your batteries
the screen should turn on and so should the NES
you should get a nice picture on the screen
if everything is not working, check the troubleshooting list below

troubleshooting
----------------------
troubleshooting: If it does not work
does the video amp work? you may have fried the transistor while soldering to it
did you reverse the screens power connections? you may have fried a fuse
do the screen and console share a common ground?
are the batteries charged?
can your batteries handle the amp draw?anything better than AAAs should work
are any wires touching that shouldnt be?
if you are using Li-ions with a protection circuit, and there was a short, unplug the Li-ions from the protection circuit, then plug them back in.if there was a short, then the protection circuit switches off the batteries


check everything and find the problem.if it still doesn't work, you may have fried something
first check the regulators.are they putting out the voltage that they need to?if they are, but the voltage drops to almost zero when you add a load,then try replacing the 7805
does the screen light up when you add power? If not, see the last paragraph
if the screen does light up, but you get no picture, then try using a different video input
if it works then, try building a new video amp for the NES
if the screen does not work after trying a different input, check the next paragraph
if the new video amp does not work, your NES is DEAD
get a new one, and be more careful with it

if your screen does not power on
------------------------------------------
what to do if your screen does not work
there is a fuse on the PS1 screen
if you reverse the power to the screen, then this fuse will blow, and the screen will appear to be dead
not to worry if you jump this fuse, the screen should work again
on the front of your screen, down by the connectors, there is a small rectangular object that has the word PS1 printed next to it
put your soldering iron on one end of it and kind of "pull" it away from its pads with the soldering iron, so that the fuse is removed and there are just two small solder pads
add a blob of solder right there, so that the two solder pads are bridged
the screen should now be working.if not, it is most likely DEAD