Hello and welcome to DIY Perspective.
In this special video I am going to show, how you can make a small and portable media
PC with integrated speakers.
This project basically consists of 4 main components – an old laptop, 30W stereo speakers
with amplifier, the case and a remote control.
So, if you are interested how I assembled all these components into all-in-one system
like this, stay tuned.
It's so much fun to take things apart if you know that you won't need to reassemble
them.
So in this case, taking apart an old laptop is like an easy puzzle.
For this build we want the main components of a laptop, like a display, battery, hard
drive, power switch, audio card, fan and main board with charging and USB ports.
Display of the laptop must be completely disassembled that we could remove hinges and Wi-Fi antennas.
I left web camera in place just because I will be placing it inside the case.
Yes, I know that sounds funny, but why not?
If you want that this media PC would be portable, it's good idea to change old batteries to
new ones.
To do that we need to disassemble the battery pack.
Most of the time batteries are sealed quite well and it's hard to open it without braking
the frame.
If you are just brute forcing into the battery like me, be careful not to short batteries
or damage the battery protection circuit.
In older or cheaper laptops, we usually can find very common 18650 lithium ion cells.
Those, most of the time, are connected in 3 series and in 2 rows parallel.
This gives total voltage of 12.6V when batteries are fully charged.
Wires like these, controls charging in each battery pairs, and this sensor monitors battery
temperature.
It is very important to remember how everything was connected together.
It is always a good idea to take few pictures of wiring before doing anything.
After de-soldering the batteries, remember that those now don't have any short circuit,
over charge and over discharge protection.
If you have a universal battery charger, you can test how much capacity are left in the
batteries.
If they still have some juice left, you can re-use them in devices that has previously
mentioned battery protections.
So, to hold the new batteries, we need to make simple batteries and protection circuit
holder.
For the batteries we can use 3 DIY battery holders, which end contacts needs to be soldered
with each other.
And by soldering additional 4 wires here, we will get holder which connects batteries
in 3 series and in 2 parallel.
Battery power connector must be extended with some extra wires as we want batteries to be
placed as low as possible, that will give more stability to this media PC.
Now we can solder all the wires back in place.
I also wrapped the base with heat resistant and electrically conductive tape.
This will act like a heat and electrical shielding when we ground it.
Just make sure that current can pass through all the pieces, as sticky side is isolated.
I connect both layers just by simply poking multiple times.
If you don't get power from reassembled battery, you might also need to plug the charger.
It makes some sort of calibration to enable that you could use your battery again.
In my case it flashes red light few times and after that battery pack is usable again.
So for now, we are done with the battery.
Next thing what we need to do, is to replace existing power button.
To do that, we need to find two wires which goes to the existing power button with a multimeter.
Now all contacts can be de-soldered, and those two power button contacts can be soldered
to extra wires which will go to the new power button.
As these wires are very thin and fragile, it's good idea to hot-glue them and wrap
in an electrical tape.
So, we have the power and we have the power switch.
Now we can test and improve cooling of the main components like CPU and GPU.
Usually laptops make annoying noise under load as they have very tiny heatsinks and
fans.
And considering that this laptop is quite old, it will usually run at a high load.
So, to eliminate that noise and heat, we need to mount bigger heatsink with less noisy fan.
As you already saw I also reapplied new thermal paste to improve heat transfer from the chips
to the heat pipe.
Bigger heatsink can be glued with thermal conductive glue, and common 12V 60mm fan can
be mounted with some tiny zip ties, though the drilled holes in the heatsink.
And to power the fan we need to connect it to the default fan connector.
Doing this way, you will lose a fan control and it always will spin at a fixed rate.
But as this connector usually provides only 5V and not 12V, fan will spin at a lower rate
and produce less noise.
One thing to keep in mind before doing this kind of modification, is that your laptop
must work without any fan connected.
If you unplug the stock fan from the main board, and a laptop fails to boot, then you
better just stick with a stock fan configuration.
So now, with most work done with electronics, we can cut pieces that will make the frame
of this media PC.
I really wanted that it had that old school vintage look with huge speakers and big control
buttons.
So simple frame design like this, will give even more old look to it.
And with plenty space inside we can later upgrade to newer parts without worrying that
they won't fit inside.
Now, the monitor frame should be quite thin, around 5mm thickness.
We can make parts thinner with a jigsaw table or just by splitting and sanding plywood.
By this extra work you will get same looking plywood front, as different thickness plywood
can have very different shades.
To finish the front, we need to cut the holes in the front face.
At first I thought I'll drill with a hole saw bit, but later I decided to use just a
jigsaw.
As these will be covered with speakers anyways.
Now we can drill pilot holes for the speaker screws and make 3 holes for the volume control,
speakers power switch and laptop power on button.
And on the other side we need to trim the plywood for those components, as it is quite
thick, to be exact 12mm thickness.
With all that done, we can finally finish the front face of the case, by gluing it in
place.
At the back, we need to glue a piece with a hole for the laptop's charging connector
and cut more pieces for separating the speakers.
As I'll be using full range car speakers, we need to drill a hole for each speaker.
That created air pressure from them wouldn't affect sound performance in a bad way.
Also, it will give better low frequencies.
And I know that this will make HiFi experts to cringe, because ported speaker box size
must be calculated precisely and the air that moves from the speakers needs to escape from
exact diameter and length tube!..
But come on, let's be realistic, this is not a HiFi system.
This is just a system that sounds 100x better than an integrated laptop speakers.
While that being said, I almost finished cutting and gluing all the parts.
I mean there is nothing important to say about it, if you have questions just ask.
I'll provide all dimension of this build in the file which you can download in the
video description below.
And now is the fun part, so first we need to mount our display.
It is easy to perfectly align it by looking from the bottom while it is powered on.
Also, it is good idea to add some double side tape and hot-glue all four corners to prevent
display from moving just for now.
I used these clips that came with the speakers, I bent them and firmly secured the display.
At this point we should connect cables that are in the back side of the main board and
secure them with duct tape, as we absolutely don't want that they disconnect while we'll
move it around.
You can see that I also glued additional heatsink on the chip on the other side.
It had a big surface to dissipate heat when the laptop was assembled.
So be aware of those.
Mounting main board and sound card isn't hard, we just need to screw them where we
can with spacers (that's plywood blocks) and small 90-degree corners.
Wi-Fi antennas can be placed with thick double side tape in each top corner, same as it was
on the laptop.
We can spark some new life into this PC, by adding solid state drive instead of an old
and slow mechanical drive.
And of course, now it's a good time to glue some small blocks which later will hold the
back cover.
Power button can be re-soldered after threading it, and the charging cable extended if needed.
We also should cover as much as possible of the inside, where batteries will be, with
heat resistant tape.
This will prevent possible quick ignition of the wood if something horrible happens
to the battery pack and will act as an electrical shielding.
And remember that by making DIY projects like this, it is your full responsibility if something
goes wrong.
With disclaimer aside, we can start making volume control for the speakers.
We need a stereo cable with 3.5 jacks in both ends, which can be cut in two pieces.
Then those two pieces can be soldered to a 10k Ohm logarithmic potentiometer like this.
Ground wires from both cables goes to the left side pins as one connection.
Left and Right audio channel wires, that will later go to the input, goes to the right side
pins.
And the output goes to the middle pins.
Red wire usually is Right channel.
If you are not sure which wire is which you can easily test it like this to find out.
Now we can make a power connector with a switch, which will power this audio amplifier.
It is a simple class D, stereo amp with Bluetooth and audio-in.
In this case, we don't care about the Bluetooth, we just need the audio-in.
When choosing speakers for the amp, always buy equal or more powerful speakers than the
amp's rating.
For example, this amp is rated at 30W for each speaker, so you need to buy speakers
which are rated at 30W each or higher like a 40W.
This way you won't burn your speakers with too powerful amp.
Finally, we can thread wires from the speakers to the amp, secure battery pack with two screws
and make battery cut off switch.
To do that, I needed to separate two positive wires and remove protection from one negative
wire.
In my case battery had two positive contacts in one side and two negative contacts in the
other side.
Cut off switch will connect batteries together, and amplifier will be powered directly from
the battery pack.
Now, everything should work perfectly.
But usually this is not how it goes.
With media PC turned on I was getting these super annoying noises.
That was kind an odd, because audio-out on the laptop and amp with the speakers worked
perfectly.
But more about this issue later.
Anyways, what's left is to make back covers.
And these are nothing special.
Top cover has holes for the fan to take in the air, and on the top, for the hot air go
out.
And also, this glued USB connector.
With all plywood parts in place, we can finally add some wood oil to get that rich wood grain
pop.
And to eliminate vibrations that we definitely don't need, we can add four soft rubber
feet in each corner.
So, now how I fixed the noise from the speakers.
First let's identify the problem.
It is called ground loop noise.
And to eliminate it, you need pass audio wires through device like this, which is called
ground loop noise isolator.
With this masterpiece installed my problem was completely solved.
So to complete this build, we can add some aluminum heat resistant tape, to shield the
inside of the case and both panels.
Make sure, that tapes make good contact with one another.
And then, we can finally connect negative contact to the inside shielding.
What this does, it shields inside electronic components from outside electromagnetic interferences.
This is one of the reasons why inside of a laptop is covered with shielding like this.
As we now are done with the build, I will go over few tips and possible modifications.
First, remove sticker or write down your laptop model with main information, as it could be
useful later, like for a specific driver.
For this build, I suggest using laptop with IPS display to get best viewing angles, as
other panels are not so great at it.
If you are using Windows 10 usually you don't need any drivers for the remote or a laptop,
it just works out of a box.
I first thought that this kind of remote wouldn't be very convenient.
But after using it with this media PC, I started to like it more than a simple remote keyboard.
And now some possible modifications, first, you can make this PC passively cooled with
a way bigger heatsink, of course if your laptop boots without a fan.
This will further reduce the noise levels and almost no dust will go in.
With that being said, for the fan you can use a small dust filter like this.
Most of the dust will be outside which is easy vacuum.
Just remember to do that, or it could severely restrict the airflow, causing component overheat
and leading to failure.
So, these were tips and possible mods.
If you liked this video give it a like, and subscribe if you want to see more content
like this.
That's all from me and I will see you next time!
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