What is a chipset, north and south bridge, types of chipsets. What is the south bridge on a laptop motherboard

One of the common breakdowns of modern computers is the failure of the south bridge. If the south bridge heats up in standby mode, one or all USB ports have failed - these are the main symptoms of its failure. Today we will show you a quick way to check the southbridge on your motherboard.

Check the F_ USB1 connector.

Let's check F_ USB2.

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How to check if the Intel South Bridge has burned out?

Fig.1 USB Data pins

On the vast majority of Gigabyte motherboards, when standby power is supplied, the south bridge begins to heat up within 5-30 seconds. If in standby mode the bridge is cold, but immediately after switching on it starts to get very hot, this indicates a malfunction of the 1.5V bridge power driver. For ASUS boards this is a cascade stabilizer made of two field-effect transistors (3.3--->2.4--->1.5), and on Gigabyte boards one or two transistors connected in parallel (for simple boards 3.3- -->1.5, for more sophisticated ones 2.5--->1.5, with 2.5 V generated by a PWM converter). In most cases, the bridge itself remains alive.

In the simplest case, with a faulty south bridge, the POST indicator shows code 25 for Award BIOS and D0-D4 or DD for AMI BIOS.

In 99% of cases, one or more USB Data pins are shorted to ground, which can be easily checked by ringing them. In the photo, all the USB Data pins for the Gigabyte 8IPE1000 rev.3.1 board that need to be ringed are circled in red.

The most difficult cases to diagnose are when USB Data does not short to ground, the standby voltages are not drained, and the bridge does not get hot even after the board is started. But there were only two such cases in my practice and this is rather an exception, but we came to the conclusion that the bridge was faulty (a replacement confirmed this) after replacing the cartoon, soldering the socket and flashing the BIOS firmware.

According to our statistics, in 60% of cases the Chinese DATA cable for cell phones is to blame. Another 30% comes from USB Flash Drive and 10% from other USB devices. However, there were cases when USB devices were not used on the board, but the bridge burned out on its own! For prevention, when actively using cellular DATA cables, it is recommended to install an additional PCI-USB controller.

www.rom.by

How to check the south bridge?

In most cases, for preliminary diagnostics it is enough to check whether the USB Data pins are shorted to ground of the motherboard. For clarity, we will show on the Gigabyte G31M-ES2C motherboard how to perform such a simple check. We just need a regular multimeter.

To do this, you need to put the multimeter in dialing mode and check the Data pins of each USB port one by one.

You need to check not only the ports that go to the rear panel, but also the connectors to which USB is connected from the front panel, so we’ll start with them. For convenience, the USB pinout on the motherboard is shown below (there are two USB ports in this connector).

We install one multimeter probe on the ground of the motherboard, with the second probe we alternately touch the Data + and Data – contacts of each port. The multimeter readings on different ports should not differ much.

Check the F_ USB1 connector.

As you can see, F_ USB1 has normal readings.

Let's check F_ USB2.

Everything is obvious here, both USB ports on F_ USB2 are shorted to ground.

The conclusion is obvious: the south bridge has failed. Replacing the south bridge is not a cheap thing; it cannot be done at home; in this case, repairing such a motherboard is not advisable.

Why is the south bridge burning down?

There can be a lot of reasons, ranging from banal overheating due to an ill-conceived or incorrectly assembled cooling system, to low-quality Chinese phone cables or flash drives. The culprit may also be a power supply that has failed.

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South and north bridge on the motherboard

A computer motherboard is a technically complex device that deserves close attention. It ensures the interconnection of all the most important components of any computer, such as the central processor, RAM, and video subsystem. The design of any of the motherboards is based on a chipset, which is formed from the north and south bridges. Read more about what the north bridge is responsible for on the motherboard, what the south bridge is responsible for, and where they are located.

What is the north bridge responsible for?

First, let's figure it out - what is the north bridge on the motherboard? The North Bridge is a controller that coordinates the operation of the most active and energy-intensive components, such as the processor, RAM and integrated graphics. It is not difficult to guess that the duties assigned to it entail increased heating, as a result of which this controller has its own cooling system. Most often it is of the passive type, but there are also examples with an active cooling system.

Where is the Northbridge located on the motherboard?

If you look at the motherboard, the northbridge is located in the upper half, closer to the central processor. This location was not chosen in vain. Firstly, all the devices that are controlled by this controller are located here. Secondly, the active cooling system of the central processor is partially involved in its cooling. This technique can be seen with the naked eye where the controller's passive cooling system is present. If you look closely, you will see that this controller is located so that its radiator is in the area where cooled air flows, pumped by the CPU cooler.

What is the south bridge of the motherboard responsible for?

The South Bridge coordinates the so-called “slow operations”, the list of which is impressive. In particular, it controls the energy saving system, system clock, BIOS, IDE, SATA, USB, LAN, Embeded Audio, etc. interfaces. The south controller is located at the bottom of the motherboard and is not equipped with a cooling system. This design feature often causes it to overheat and ultimately cause the entire motherboard to fail.

In a normally functioning computer, the temperature of the south bridge is 30 °C lower than that of its north bridge. Therefore, there is usually no reason to worry. The reasons for its overheating, leading to a fatal outcome, can be different - poor contact of the chip with the motherboard, a short circuit in the USB connector, or a static discharge transmitted via the USB interface.

Canal-IT.ru

How to check bridges on the motherboard?

Help me urgently!)) One person told me that the bridges on the motherboard burned out (or on the way to another world). How can you check this with only straight hands), desire and a multimeter? The hardware consists of only 2 power supplies, this same motherboard, 3 video cards (one of them is 100% working, this system was once run on it) and a processor and RAM for it.

By the way, the board is old, it has all sorts of LPT and COM connectors, in addition to USB, so (maybe) you can observe some diagnostic signals on them

Question asked over a year ago
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hmm.. well, the north bridge is slots for ddr. memory does not see - the north bridge is out. The north bridge also controls the video card slot. the south bridge rules everything else - pci slots, connectors on the motherboard, all sorts of ide, sata, usb, lan, audio Like 2 2 comments
What kind of mother? Disconnect all peripherals, video and memory from the motherboard with the exception of the processor, connect the speaker. Check: resistance between RESET and common, USB D+, D- and common. Try placing a piece of eraser under the bridge from the bottom of the motherboard and press the radiator to the board with your hand GENTLY WITHOUT DISRUPTIONS and try turning it on. Does the speaker make sounds? What are the voltages on the processor, memory, etc.? Like 1 Comment

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South bridge failure is the most common problem on boards using i845/i865/i848 series chipsets. The main reason is the burnout of the USB controller built directly into the south bridge. However, the purpose of this article is not to search for reasons, but to find ways to “bring back to life” such boards.

In the event of a failure due to the “dying” of the USB controller (in the south bridge), the following main options for the behavior of the motherboard are possible:
1. The board does not turn on (forced start gives zeros on the postcard), the south bridge is already heating up from the standby power supply. The board starts, but freezes at POST code 25 (for Award BIOS 6.0) or D0 (for AMIBIOS8).
2.The board starts, but freezes at POST code 25 (for Award BIOS 6.0) or D0 (for AMIBIOS8).
Solution methods:

1. Restoration using the "annealing" method
The first case is especially typical for Asus P4P800 series boards. With this option, you can and should use the “annealing” method. What does "annealing" mean? This means that in order to prevent shortening of the power supply to already burnt out parts (inside the south bridge), a deliberately “burning” voltage is supplied to them until they finally burn out, thus ceasing to interfere with the functioning of all the others, which, as a rule, remain perfectly serviceable , blocks inside the chip.
"Annealing" of standby power supply
We check whether the duty 5V and 3.3V are sagging.
We supply standby power and check whether the standby 5V and 3.3V are sagging. If yes, we supply “power” 5V/3.3V to them and briefly turn on the power supply (with a jumper on PS_ON). We remove all jumpers and check the control voltages. “We got up” - good, if we didn’t get up - we try again, and several more times, it doesn’t work - we leave the “power” jumpers and move on.
"Annealing" the load of capacitors connected to the outputs of internal standby sources
We look for three capacitors on the board connected to the outputs of internal standby 1.5V sources (VCCSUS1_5A,B,C) - at least one of them has dropped to 0.2..0.4V (as a rule, this is only VCCSUS1_5A) and “anneal” its load. To do this, we first supply 1.5V (possibly from Vcc of the installed processor, or from Vmch/agp). If this does not help, we make several short-term short circuits to 2.5V memory power supply or, in extreme cases, 3.3V. It is dangerous to burn out five volts - there is a possibility that the south bridge will die for good. If 2.5V does not help, before applying 3.3, it is recommended to try 3.3VSB first (as a relatively low-current source). If as a result the voltage rises to the required 1.5V, then the operation was successful! (The temperature of the south bridge should decrease by 15-20 degrees compared to what it was before the “annealing”).

2. Recovery by flashing the BIOS
The second case is typical for Gigabyte 8IPE1000 series motherboards. In this case, in general, it may be enough just to flash the “correct” BIOS.
Using ProBIOS
To check for the possibility of reviving boards with such a problem (stopping at the 25th postcode for Avard and D0 for AMI), you can and should use a “probios” (tested bios). ProBIOS is a special BIOS suitable for most motherboards based on i845/i865/i848 + ICH4/ICH5 logic. It contains initialization of only “vital” parts of the board (which allows it to be used as a test and for all “other” cases - just repairs), including skipping the procedure in which in “standard” (ordinary, “native”) BIOS board freezes.

So, as a result, we should get a reduction in the heating of the south bridge (by 15-20 degrees compared to the temperature before the “treatment”), as well as a fully functional motherboard. True, adjusted for the missing USB ports, but nothing will prevent you from installing an “external” PCI USB controller and thus getting a completely working system.

The other day I encountered the following problem - the computer turns on, but does not start, there is no image on the monitor (the indicator is blinking), all the diodes on the front panel of the system unit are lit, the system unit does not produce sound signals (i.e. the BIOS does not boot), the hard drive and others disk drives do not start. When disassembling the system unit and inspecting and “feeling” it turns out that the south bridge (the third largest chip on the motherboard after the processor and the north bridge) gets terribly hot - it heats up in 2-5 seconds so much that you can’t hold your finger. These are symptoms that the south bridge on the motherboard has failed - perhaps permanently, but perhaps not. This happens mainly due to the fact that the flash drive was pulled out of the USB “hot” or some USB device was “shorted” - in general, a short circuit in the USB. You should not try to turn on/off the PC many times in the hope that it will come to its senses and start working - this does not happen, such switches with overheating of the southerner can drive the unfortunate microcircuit into the grave completely.

The problem, of course, is unpleasant, but still you shouldn’t throw out the motherboard - there is a possibility that the south bridge can still be saved or replaced. Another option is to “anneal” the USB ports, but this is not always a solution, because... without USB, a specific machine is not needed at all (as in my case), another option is to replace several power mosfets of the south bridge - this often happens due to their malfunction, and the last option is to completely replace the south bridge microcircuit - if the bridge is completely dead, but we should not forget that it is not the bridge itself that is to blame - there are still elements that will have to be replaced.

Of course, I won’t write here how to do all this, because you can’t cover everything in one post - for such purposes there is an interesting, and in my opinion, the best Russian-language site - http://www.rom.by. There is a lot of information on repairing motherboards, power supplies and other very useful materials. It is also worth paying attention to the resource http://monitor.net.ru, there is also a lot of necessary and useful information here - a forum where issues of repairing a huge amount of equipment are discussed, I found it very useful there - the "Files" section, from where you can download fundamental device diagrams necessary for subsequent repairs. In order to download this or that circuit, during registration you need to answer 4 questions from the field of electronics and electrical engineering. This is necessary to weed out non-professionals.

And finally, a warning - you should not go into the jungle of microelectronics and repair something yourself if you are a non-specialist, have no experience in such repairs or do not understand such issues at all - as an option: read manuals, manuals, textbooks (regular textbooks on electrical engineering and electronics), learn the basics, etc. or - give the broken piece of hardware to a specialist, otherwise - either you will bring the half-dead device to the grave for good, or you will ruin your skin, or maybe both.

And here is some material for you, food for thought, so to speak.

South bridge ICH5 burned out - repair WITHOUT re-soldering!

Material from ROM.by - this is the best website for motherboard repair!

In the event of a failure due to the “dying” of the USB controller (in the south bridge), the following main options for the behavior of the motherboard are possible:

The board does not turn on (forced start gives zeros on the postcard), the south bridge is already heated from the standby power supply. The board starts, but freezes at POST code 25 (for Award BIOS 6.0) or D0 (for AMIBIOS8).

The board starts, but freezes at POST code 25 (for Award BIOS 6.0) or D0 (for AMIBIOS8).

1. Restoration using the "annealing" method

The first case is especially typical for Asus P4P800 series boards. With this option, you can and should use the “annealing” method. What does "annealing" mean? This means that in order to prevent shortening of the power supply to already burnt out parts (inside the south bridge), a deliberately “burning” voltage is supplied to them until they finally burn out, thus ceasing to interfere with the functioning of all the others, which, as a rule, remain perfectly serviceable , blocks inside the chip.

"Annealing" of standby power supply

We check whether the duty 5V and 3.3V are sagging.

We supply standby power and check whether the standby 5V and 3.3V are sagging. If yes, we supply “power” 5V/3.3V to them and briefly turn on the power supply (with a jumper on PS_ON). We remove all jumpers and check the control voltages. “We got up” - good, if we didn’t get up - we try again, and several more times, it doesn’t work - we leave the “power” jumpers and move on.

"Annealing" the load of capacitors connected to the outputs of internal standby sources

We look for three capacitors on the board connected to the outputs of internal standby 1.5V sources (VCCSUS1_5A,B,C) - at least one of them has dropped to 0.2..0.4V (as a rule, this is only VCCSUS1_5A) and “anneal” its load. To do this, we first supply 1.5V (possibly from Vcc of the installed processor, or from Vmch/agp). If this does not help, we make several short-term short circuits to 2.5V memory power supply or, in extreme cases, 3.3V. It is dangerous to burn out five volts - there is a possibility that the south bridge will die for good. If 2.5V does not help, before applying 3.3, it is recommended to try 3.3VSB first (as a relatively low-current source). If as a result the voltage rises to the required 1.5V, then the operation was successful! (The temperature of the south bridge should decrease by 15-20 degrees compared to what it was before the “annealing”).

2. Recovery by flashing the BIOS

The second case is typical for Gigabyte 8IPE1000 series motherboards. In this case, in general, it may be enough just to flash the “correct” BIOS.

Using ProBIOS

To check for the possibility of reviving boards with such a problem (stopping at the 25th postcode for Avard and D0 for AMI), you can and should use a “probios” (tested bios). ProBIOS is a special BIOS suitable for most motherboards based on i845/i865/i848 + ICH4/ICH5 logic. It contains initialization of only “vital” parts of the board (which allows it to be used as a test and for all “other” cases - just repairs), including skipping the procedure in which in “standard” (ordinary, “native”) BIOS board freezes.

3. Result

So, as a result, at the output we usually get a reduction in the heating of the south bridge (by 15-20 degrees compared to the temperature before the “treatment”), as well as a completely functional motherboard. True, adjusted for the missing USB ports, but nothing will prevent you from installing an “external” PCI USB controller and thus getting a completely working system.

Let's talk about motherboard controllers. In particular, we will examine the question of what the north and south bridges are. The average computer user is unlikely to have ever encountered such a term. However, if this very ordinary user, after a PC breakdown, took it to be “torn to pieces” at a service center, sometimes he may receive a simple answer: “The South Bridge burned down, it cannot be restored!” The answer is reassuring, you need to buy a new motherboard. So that’s how it is, replacing the south bridge is really a thankless task, and maybe even unrealistic. But people, as a rule, do not know what the concepts of north or south bridge mean.

The north and south bridges of the computer (or, more correctly, the motherboard) are two main functional controllers that are responsible for the operation of all components of the motherboard and are called a chipset. Let's look at them separately. You can read more about the north and south bridges. Let's start with the north bridge.

Northbridge is a system controller, which is one of the elements of the motherboard chipset, responsible for working with random access memory (RAM), video adapter and processor (CPU). The north bridge is responsible for the system bus frequency, the type of RAM and its maximum possible size. One of the main functions of the north bridge is to ensure interaction between the motherboard and the processor, as well as determine the operating speed. Part of the northbridge in many modern motherboards is the built-in video adapter. Thus, the functional feature of the north bridge is also the control of the video adapter bus and its speed. The north bridge also provides communication between all of the above devices and the south bridge.

The Northbridge gets its name from its “geographical” location on the motherboard. Externally, it is a square-shaped microchip located under the processor, but on the top of the motherboard. Typically, the northbridge uses additional cooling. Usually this is a passive radiator, less often - a radiator with active cooling in the form of a small cooler. This is due to the fact that the temperature of the north bridge is always about 30 degrees Celsius higher than the temperature of its “southern brother”.

The elevated temperature is quite justified. Firstly, the north bridge is located in close proximity to the central processor, and secondly, it is located above the video card, hard drives and south bridge. This means that some of the heat from the above devices reaches the northbridge. And thirdly, the most important thing is that the north bridge is responsible for processing commands from the most powerful components of the system - the processor, memory and graphics. Therefore, we will assume that an increased temperature rating is the norm for the north bridge of any motherboard.

South Bridge

The Southbridge is a functional controller known as an input/output controller or ICH (In/Out Controller Hub). Responsible for the so-called “slow” operations, which include working out the interaction between the IDE, SATA, USB, LAN, Embeded Audio interfaces and the system’s north bridge, which, in turn, is directly connected to the processor and other important components, such as RAM or video subsystem. The south bridge is also responsible for processing data on PCI, PCIe and ISA buses (in older motherboard models).

The list of motherboard systems supported by the south bridge is quite large. In addition to the above IDE, SATA, USB, LAN and other things, the south bridge is also responsible for the SM bus (used to control fans on the board), DMA controller, IRQ controller, system clock, BIOS, APM and ACPI power supply systems, LPC bus Bridge.

As a rule, the failure of the south bridge puts an end to the life of the motherboard. It is the south bridge that is sometimes the first shield to take the blow. Due to technological features, this is so. The reasons for the “death” of the south bridge are an order of magnitude greater than those of the north bridge, because it works directly with “external” devices. Thus, a common cause of YUM failure is simple overheating caused by a short circuit, for example, in a USB connector. Or there is a power failure on the hard drive. Because In most cases, the southbridge is not equipped with an additional cooling system; it overheats and burns out. Less commonly, the reason for the breakdown of the south bridge is a manufacturing defect. Deformation (excessive bending) of the system board also leads to increased heating of the south bridge with subsequent failure.

To extend the life of the south bridge, you can install homemade cooling. A simple passive heatsink with hot melt adhesive can extend the life of your motherboard in case of overheating symptoms. It is not easy to detect such a symptom. Not all motherboards are equipped with thermal sensors in the north and south bridges of the system board. Recently, to solve the problem of south bridges, some motherboard manufacturers began to equip these chips with additional passive cooling and a temperature sensor, which, if something happens, will notify the user about the problem. Note, however, that under normal conditions there is no reason for increased heating of the south bridge, but remember that the south bridge is responsible for many devices that could contribute to its overheating and combustion. Be careful.