This is a PDF Service Manual for the Acer Aspire T650 series desktop computers, from Acer Support,http://support.acer.com/acerpanam/manuals/acer/0000/servicemanuals/S.G_AS650_E500APF5_BOOK.book.pdf
After you click on the link you won't see anything happening for up to 30 seconds. The file is downloading in the background.
If you see the first page, and the file is still downloading, let the file download all the way before looking though it.
(Should the Service manual link not work for you, state so in a Comment)
Proper computer speak for motherboard is Mainboard. The mainboard is shown on Page 15.
Connections to the Headers on the motherboard, are shown on Page 19.
Orienting the motherboard so the Processor is to the top, and Ram Memory slots to the right, the Front Panel header is on the bottom right of the motherboard.
The Front Panel header, is where the various cables from the Front Panel of the computer go.
(Front Panel being the plastic panel in the front of the computer. For this computer, the Power On button, two USB ports, Speaker/Headphone jack, and Microphone jack are in the front panel)
To the left, and down a little bit, of the processor socket is the 4-pin ATX +12 Volt header.
Square in shape, white in color, 4 socket holes.
This is where the 4-pin ATX +12 Volt power cable plugs into. (Two Black wires, two Yellow wires)
This is power for the Processor. If it isn't hooked up, the Processor won't turn on. No power.
Below the Processor socket's left corner is the header for the System Fan. The computer case fan. You will see there are 4 pins.
One for 12 Volts.
One for Ground.
One for detecting the RPM's of the fan. (Revolutions Per Minute)
One for varying the RPM's of the fan. This is the sensor connection.
To the upper right of the motherboard is another small white header. (Connector) This one has 3 pins. This is where the Processor (CPU) fan plugs in.
The long white connector below the CPU fan header is a 24-pin ATX main power connector.
The 24-pin ATX main power cable plugs in here.
The Front Panel header, or PANEL 1, is on the very bottom right.
Has two rows of pins.
Starting from the left side going right, there are 4 pins, NO pin, then 3 pins on the Top row.
Starting from the left going right, there are 7 pins across the bottom.
The pins on the Bottom are numbered Odd.
Starting from the left going right, the pins are numbered,
1, 3, 5, 7, 9, and 13.
The pins on the Top are numbered Even.
Starting at the left going right the pins are numbered,
2, 4, 6, 8, NO pin, 12, and 14.
1) Pins 2 and 4 are for the MSG LED
(Pin 2 is for the + positive connection)
2) Pins 1 and 3 are for the HarDDrive activity LED
(Pin 1 is for the + positive connection)
3) Pins 5 and 7 are for the Reset switch. (Button)
(Pin 7 is for the + positive connection)
4) Pins 6 and 8 are for the Power On switch.
(Pin 6 is the + positive connection)
5) Pins 11 and 13 are for the ODD LED
(Pin 11 is the + positive connection)
6) Pins 12 and 14 are for the LAN LED
Page 116 shows an exploded diagram of the inside, of the T650.
Acer doesn't give info as to who made the motherboard for them. (All pre-built computers have their parts made by someone else)
Due to it's square shape it's a Micro-ATX form factor motherboard.
9.6 inches by 9.6 inches, or 244mm by 244mm.
(The Micro-ATX form factor can be as small as 171mm by 171mm.
The following will give you more information,http://en.wikipedia.org/wiki/Motherboard_form_factor
Information about the Aspire T650 motherboard from me,
1) Motherboard chipset:
The motherboard chipset, is what determines what components are supported on a motherboard.
(Chip and Chipset are slang terms for I.C. Integrated Circuit)
The motherboard chipset is the Northbridge and Southbridge chip.
The Northbridge chip determines what Processors, and Ram Memory are supported, as well as what High Speed graphics are supported.
(The Northbridge chip handles the faster processes of the computer.
AGP and PCI Express are high speed graphics.
Any graphics card inserted into a PCI slot, is low speed graphics. This is handled by the Southbridge chip. It's a slower process. Integrated graphics are also handled by the Southbridge chip.
You may wish to view this motherboard diagram,http://en.wikipedia.org/wiki/File:Motherboard_diagram.svg
CPU stands for Central Processing Unit, or for short - Processor)
The Aspire T650 motherboard has an LA 775 processor socket.
The Northbridge chip is an ATI RC410
The Southbridge chip is a ULI M1573
Underneath the processor socket is the Northbridge chip. It's sitting diagonally, and has an aluminum heatsink sitting on top of it.
Below the Northbridge chip is a PCI-Express x16 slot used for a graphics card.
Below the PCI Express x16 slot is a PCI Express x1 slot. White in color, much shorter than a PCI slot.
There are two white PCI slots below the PCI Express x1 slot.
To the right of these white PCI slots is the Southbridge chip. ULI M1573
To the right of this chip are 4 SATA headers.
Below the 4 SATA headers is the Front Panel header.
Are you having problems connecting components?
Do you need to know what components you can upgrade to?
(Processor, Ram Memory, graphics card, power supply, etc)
If so, simply state what information you need in a Comment.