Workshop 01.1 - Hardware HP-Elitedesk 800
This workshop is an introduction to the hardware practice of The Siganto Digital Learning Workshops (SDLW). In the next three hours you will:
- Identify your computer
- Learn the external ports,sockets and buttons
- Know the internal components
- Take apart and re-assemble your computer
If you are scared of breaking your new computer, don't worry, the SDLW program is all about overcoming that fear. We'll just keep plugging cables, pulling and replacing components over and over to build your practical skills.
By the end of this workshop you’ll have the skills to strip your computer bare in less than 15 minutes.
And if you break something beyond our capability to fix it, every workshop has a few extra computers which we can use for spare parts.
What Kind of Computer is this anyway?
Breaking down the name and the labels on your computer is the first step to finding the basic information about your computer.
Let's look for details on the outside of your case, try to find the label that says;
- The manufacturer - Hewlett Packard.
An enormous global technology company, HP supplies these computers to large organisations hundreds at a time.
- The basic model - EliteDesk 800.
The model usually has a number and a name. When the number changes it's usually because the model is upgraded with newer or better parts
- The Form Factor or size = Small Form Factor (SFF) .
SFF means the tower or 'base unit' case has a Small Form Factor. It is smaller than the average desktop PC to maximise space in offices. This is important information, as it means any hardware you may like to add to your computer at a later date has to fit in the case!
- And the type of computer - PC - Personal computer, intended for one person to use at a time.
Is there any other information you can find?
- What do the labels on the side of your computer mean?
- Can you find the operating system that used to be on the computer?
These are the main safety issues that have to be identified before we start.
Always unplug the power cable before opening the case!
Some more general tips;
- When unplugging or plugging cables, try to grab the connector, not the wire.
- Screwdrivers are sharp! Try to be as gentle as possible when using them.
- The case and components have sharp edges, take care when adding or removing components.
Finally - if you are getting frustrated, down tools and have a break or a chat, there is no rush and help is always available.
Taking a computer apart requires just a few tools, enough bench space to lay out all the components and a little patience. You'll be provided with the right tools for your workshops.
A general computer tool kit includes;
- Assorted Philips and flat-head screwdrivers
- Cloth wipes
- Spray and wipe cleaner
- Paper towel
- Thermal paste
- Vacuum cleaner or compressed air can
Outside the Box
First, we'll be dealing with just the main body of your computer. Your computer could have had a hard life, being kicked around under an office desk or used as a public access computer, so we'll give it good clean. wrap
Grab the big black box and put it on your work table. While you are cleaning the computer, lets find out what we can from the outside of the case.
Ports, Sockets and Buttons
All desktop computers have a few standard connection points called ports or sockets on the front and back of the tower case. Ports vary in shape, size and colour to ensure we don't plug in cables incorrectly. We'll go through the ports on your HP8100 one by one.
There is always a three-pin power socket on the Power Supply Unit (PSU).
One or more Universal Serial Bus (USB) ports, for USB devices.
Can you name three things that connect over USB?
Two video outputs that can be plugged into a monitor or TV Video Graphics Array (VGA) ports;
and a more recent type; Display Port
An ethernet port for connecting to a network cable, used to connect to a network and access the internet.
Audio sockets, which accept audio connectors, also know as plugs or jacks.
This is how you get audio (sound) in and out of your computer. Blue is for audio in, for a microphone or output from an another device, and red is for audio out, for listening with headphones or speakers.
Legacy ports, which are not so commonly used on modern computers include
PS/2 ports - for older keyboard and mouse connectors
Serial ports - commonly for connecting older industrial devices
Inside the Box
It's time to get started!
With your computer flat on the desktop and facing you, open the case using the latch at the back.
Keep your case lid close by. We will use it to store all the parts and keep them in one place.
Before you touch anything inside your computer discharge any static electrical charge you might have on your body,
as static 'shock' can damage electronic components. This is as simple as touching a large metal object - like your computer case, before touching any components. Now you can get inside your computer with the vacuum, being careful not to hit any components.
Check out the general level of dust and gunk inside your computer. Look around the vents and fans.
If you see clumps of dust, grab the vacuum or a compressed air can and give it a going over from the outside.
And the inside
You can also wipe down the inside of your computer's metal case with a cloth.
Once you've got a nice clean computer, have a look around the inside of it and see if you can identify anything. Don't worry if it's all unfamiliar.
By the end of the workshop you'll be able to name and describe all these parts. Here is a quick overview to get us started.
Power Supply Unit
The Power Supply Unit (PSU) converts the electricity from your wall sockets, called the mains voltage (240 volts), into the smaller voltages used by your computer.
The PSU can hold dangerous voltages even after being switched off and unplugged. Never take it apart!
The big green board, also called a mainboard is the central part of your computer. All the other parts are connected to it in some way. It is mostly covered by other parts.
The hard drive - also called a hard disk is a permanent store of information or data. This is where we will install the Operating System later, and where you will store your files like music, movies or documents. The amount of information stored, or capacity is measured in gigabytes.
The DVD drive reads and writes Digital Versatile Discs. A DVD drive spins the optical disc at between 500 and 2000 revolutions per minute (RPM). DVD disks are another storage media and can store video, audio or other digital data.
PCI expansion slots
The PCI expansion slots are used to increase the things your computer can do. This is where you would add a video card
Random Access Memory (RAM)
RAM is where your computer stores data it uses to run programs. Unlike your hard drive, the data in RAM is gone when you turn off your computer.
Central Processing Unit (CPU), heatsink and Fan
The CPU is the 'brain' of your computer. It contains hundreds of millions of transistors that generate heat. In this model the fan is attached
Power cables carry power from the PSU to various components.
SATA data cables carry information between components.
What IS a computer?
Now that you've seen each part separately, lets talk about what each part does. Here is one way 1) to think about it, using a restaurant as an analogy;
A computer is like a kitchen at a restaurant. The computer's processor is like a chef, who works to prepare the food. The faster the chef, the faster food is ready. A dual-core processor is like having a kitchen with two chefs, so two things can be prepared at the same time.
The computer's RAM is like bench space. Everything in RAM is easy for the processor to get at. If you have a lot of bench space, the chef can work on preparing more things at once. If you don't have enough bench space, the chef can't work on as many things. Some software uses a lot of RAM, just like some recipes call for a lot of ingredients.
The computer's hard drive is like the cupboards and refrigerator. These spaces hold the ingredients until the chef needs them. If space runs out, then the old ingredients need to be thrown out to make room for new ones.
You, the computer user, are then the customer who is ordering things from the kitchen. If the chef is slow, or there isn't enough bench space, it's going to take longer for things to get done, especially if you are ordering a lot of things at once.
Taking it apart
Before we start removing parts it's a good time to take a photo of your computer with your phone, so you can refer to it later.
Notice the green tabs and catches all through your computer? These are designed to make it possible to pull apart most of your computer without any tools.
Remove the DVD Drive
Lift up the housing unit that holds the DVD drive and Hard Drive. The DVD drive is installed in a movable bay for easy access.
Unplug the power and data cables from the DVD drive.
Push the housing unit back down once you have removed the cables from the back of the DVD drive. Use the green tab at the back of the DVD drive to release it from the housing.
Slide the DVD drive carefully out through the front of the PC
Have a look at the DVD drive label. This information is how you find out how to replace or upgrade you drive.
You should be able to find the:
- Type of discs the drive can read and write
- DVD drive Form Factor (the physical size measured in inches)
- The speed of the drive
- The type of connection
Remove the Hard Drive
Unplug the power and SATA cables from the hard drive.
Push down the green tab on the right of the drive bay and slide the hard drive forward.
Lift the drive straight up and out.
Free the cables from the cable guide.
and unplug the SATA cable from the motherboard.
The hard drive label will tell you:
- The capacity in gigabytes
- The form factor (the physical size measured in inches)
- The speed at which it spins
- The manufacturer
Remove the PSU
Now we will unplug all the power supply cables on the motherboard.
- The connectors on these cables have small squeeze tabs to release them.
- Squeeze the tabs and wiggle gently to remove.
Once you have unplugged all the cables, there is a metal tab that has an arrow on it, as per the image below;
Press down on the arrow and slide the PSU in the direction of the arrow;
You should feel the PSU slide out of the casing.
Once the PSU is free from the base, lift out gently and place next to the PC case.
Once again, take a look at the PSU label. Try to find:
- The input voltage(s)
- The output voltages
- The maximum power (in watts)
Remove the RAM
The RAM is held in by tabs (or clips) in sockets on the motherboard.
Press hard on the tabs on either side of the first RAM stick.
Pull the RAM out.
Once the ram is free don't touch on gold parts. Why? Your skin cells and sweat can cause corrosion
Also don't touch the memory chips. Why? Static electrical discharge can easily damage or destroy memory chips.
Put the RAM down carefully and repeat for the second stick.
Examine the label for clues about the replacing or upgrading your RAM. To find your RAM in a shop you will need to match the module name which is written on the stick, to the standard name which is what the RAM is sold as.
Here is a table of common RAM types.
Remove the Front Face
We need to take off the front panel before we can go any further. This panel has a button that connects to the power switch.
There are three tabs to be lifted on the top.
And the panel should come straight off.
Remove the Fan Cover
You can flip up the fan cover so it is out of the way while you take apart the computer, but it is also very simple to remove.
Gently pull the fan cover tabs connected to the PC case and it should come free.
Release the Motherboard
Unplug the remaining cables connecting to the front panel. These cables are connected to headers on the motherboard at the lower left. There is the power header,
the front USB header,
the front audio header,
the speaker header
and the intrusion switch.
Remove the eight screws securing the motherboard, leaving the four screws around the CPU for the next step.
Remove the Heatsink
This is a tricky job. When we take off the heatsink it is important not to touch the sticky paste on the heatsink or on the top of the CPU. This paste is called thermal paste or thermal transfer compound.
The CPU heatsink is directly connected to the CPU, held in place under pressure by four screws. Unscrew the four screws.
Lift the heatsink straight up.
Place your heatsink carefully upside down to avoid smearing the paste.
- What kind of metal is your heatsink make of?
- Why do we need to use thermal paste?
Remove the Motherboard
The motherboard can only be removed at a certain angle. Take this step slowly and ask for help if you get stuck.
Lift the motherboard up from the front, then slide it gently forward to free the sockets at the back.
Lift the motherboard clear, twisting to clear it from the case. Put it down in a clear space.
Have a look at your motherboard - see if you can find the labels for:
- PSU connections
- Front panel connectors
- USB and SATA connectors
Remove the CPU
The CPU and CPU socket are the most delicate parts of your computer. Be extremely careful with this step.
The CPU attaches to the motherboard in a socket held in place with a gate. Press down and then push the lever on the gate to the side. It will pop out.
Lift the gate up.
Carefully pick up the CPU with two fingers, from the edges that have a small notch in the socket.
Have a look at the underside of the CPU - once again, don't touch the gold parts.
Look the CPU socket. Look closely and you'll see hundreds of tiny pins. Each pin connects to a gold circle on the base of the CPU.
Place the CPU upside down on top of your heatsink.
End of Part One
Well done! You are exactly halfway there! Time for a break and don't forget to wash your hands..
Part Two: Putting it back together
To re-assemble your computer you need to follow almost the exact same steps in reverse. You should expect it to take at least the same amount of time to put your PC back together. Take it slowly and remember to refer to your snapshot or the image in step 01 of the first session if you can't get a part to fit.
Clean the CPU and heat sink
Once the heatsink paste is exposed to air it will dry quickly. We need to scrape the old heat sink paste off and apply new paste.
Grab a clean cloth, lift the CPU off the heatsink and flip it over. Wipe the CPU until you can clearly read the text stamped on the CPU itself.
What can you read on the CPU itself? Can you find the:
- CPU speed
- Model number
- Where it was made?
Check where the notches are on the sides of the CPU, then place the CPU gently back in the socket with notches lined up for safe keeping. It will only fit one way!
Next we clean the heatsink. Grab your cloth and wipe with the grain.
Apply new Thermal Compound and Reseat the CPU
Lift your CPU out of the socket and squeeze a grain-of-rice size drop of thermal paste onto your CPU.
Flip the CPU around and smooth the paste onto the heat sink until the CPU is mostly covered (this step in not essential)
Put the CPU back in the socket and close the gate.
Ease the motherboard back in the same way you removed it. Tilt, then line up the back sockets. Gently lower the board in place.
Replace and tighten the six screws, making sure you leave the four holes spare for the heat sink. You might need to push the motherboard forward to get the first screws into place.
Line up the heat sink and lower it gently onto the motherboard, replace the screws and tighten firmly.
Replace Front Panel Headers
Replace the front panel headers one at a time, pay attention to the colours.
Replace the Fan Cover
Click the fan cover back into place.
Replace the Front Panel
Replace the RAM one stick at a time, into the two black sockets.
The notches in the RAM stick will line up with breaks in the RAM socket.
Push the RAM firmly into the socket.
The tabs on each end of the RAM sockets will grab onto the RAM stick and hold it into place. Repeat with the second RAM stick.
Slide back into place
Re-connect the PSU cables to the motherboard - remember they only fit ONE way.
Install the Hard Drive
Connect the power and SATA cable to the hard drive. Remember to use the L-shaped connector on the drive.
Lift up the PSU again and slide the hard drive down into the bay, then push forward to lock it in place.
Plug the SATA cable into the motherboard.
Install the DVD Drive
Slide the DVD drive down into the bay.
Then push forward until it clicks.
Connect the power and SATA cables to the DVD drive.
Make sure the cables run through the cable clip.
Plug the SATA cable back into the motherboard.
Lever the drive bay down and back into place.
Close the Case
Nearly there. Before you close the case, check to see the cables are routed neatly through the clips.
And that the DVD drive bay and PSU swings down flat.
Shut the case and you are done!
Practice Makes Perfect
Congratulations! Well done on completing your first computer rebuild. With you new skills you will be able to repeat the whole process in half the time. So lets do it all again!