# Has the AGP port on my motherboard blown?



## vvuuren (Nov 7, 2006)

Upon turning on my PC, I found that it wouldn’t boot up and my keyboard lights didn’t flash once like normal. However, the DVD rom's lights came on and all the fans are working.

I removed the RAM and swopped them around and still the same problem. When I remove my graphics card and connect my screen to the onboard graphics my pc boots up and works fine, so I thought that it might be the graphics card. 

But I tried another graphics (which I know for sure works) and it had the same effect. Pc doesn’t boot up.

From this I concluded that it is not my Memory, Motherboard, CPU or graphics card.

So, can this be that the AGP port on my motherboard has blown or something? If not then I honestly don’t know what the problem is. :sigh:


----------



## Fr4665 (Nov 18, 2004)

maybe the cmos was reset and the onboard is thinking its the main video card ...

plug ur monitor into the onboard and boot into the bios and go to advanced settings and find the agp card settings somewhere in the bios. disable onboard video by giving it no access to system ram or there might be an option to turn it off.

once its turned off plug ur agp card in and hook the monitor up to it.


----------



## vvuuren (Nov 7, 2006)

I have already tried that, but to no avail. My system does not boot up when I put a graphics card in the AGP port, only when I activate my onboard graphics.


----------



## Fr4665 (Nov 18, 2004)

can u test a PCI video card ?

or test hte AGP card in another system ?


----------



## vvuuren (Nov 7, 2006)

I dont have a PCI graphics card.

I have two AGP graphics cards. A ATi X1600 Pro 256MB AGP (NEW) and a Ati Radeon 9600 128MB AGP (OLD). I know for sure that the radeon 9600 card works.

I have tried both AGP cards and I get the same problem with both. So I am pretty sure that it is not my graphics card, rather a problem with the AGP port on the motherboard or something.


----------



## vvuuren (Nov 7, 2006)

What I would like to know first of all, is it possible for the AGP port to blow?


Anybody out there? TECH SUPPORT?


----------



## Fr4665 (Nov 18, 2004)

well yeah it is possible it doesnt blow it breaks or burns out. it has happend in the past week twice and someone posted about this cause they were looking for a PCI video card solution.


----------



## vvuuren (Nov 7, 2006)

Yeah sorry, that is what I meant... Break or burnt out!


----------



## Done_Fishin (Oct 10, 2006)

Pvisagi said:


> Upon turning on my PC, I found that it wouldn’t boot up and my keyboard lights didn’t flash once like normal. However, the DVD rom's lights came on and all the fans are working.
> 
> I removed the RAM and swopped them around and still the same problem. When I remove my graphics card and connect my screen to the onboard graphics my pc boots up and works fine, so I thought that it might be the graphics card.
> 
> ...


Thoughts
1. if you leave the monitor connected to the onboard connector, does it display? (when the AGP is installed too!)
2. Is there a BIOS configuration that selects the "other" card by disabling the onboard graphics?

Experience:-

Less than a year ago , I accepted a job in a lab to do testing & analysis of materials. I was given a desk and a chair but no PC until I asked where I was supposed to keep my notes & write reports.
So they brought in this PIII which they said was working but used to be in a different dept. I should use it but not delete anything.
On booting I found that I had no display. First thing I doid was to bring a PCI graphics in from home and see whether the display would work using an differnt card. On Opening I found that 1. it was fitted with an AGP card, and 2. there were 2 swollen caps close to the AGP slot.
I removed the AGP and put in the PCI, noted the caps values then powered on. I had display. he folowing day I brought a couple of caps into work from home and replaced the bad ones in the PC. Replacing the AGP and taking back my PCI graphics card had the system back up & working as it should have been when I was given it.
My daughter was given a desktop PC (PIII) which had been replaced due to upgrade. It wouldn't post a display either. I opened it up removed the AGP & put in a PCI to get the display working again. I could see no other fault on the mobo. I didn't have a spare AGP card to try so I left it as it was, with the PCI card installed.


----------



## vvuuren (Nov 7, 2006)

What is Caps?


----------



## Done_Fishin (Oct 10, 2006)

sorry forgot who I was talking to someone outside the trade. 
caps = capacitors. These are tubular objects on the motherboard, sitting like small towers with flat tops. 

http://electronics.howstuffworks.com/capacitor.htm










They are responsible for keeping voltages (reasonably) stable on the power supplies. When they are failing, they lose their ability to function properly. SOME actually start to deform the roof of the capacitor, pushing the top upwards and may even leak causing a discolouration on the surface of the capacitor. Others start to force the outer body up off of the innards, without causing a dome effect, which is more difficult to see, but may leave a substance called electrolyte on the motherboard.

you can see pictures here.

http://www.trendit.co.za/capacitor.htm

like this 










there are only a couple of caps that are looking good in this picture, the ones that look domed (7 of them approx central in picture) are definitely BAD. If you see anything that looks even slightly domed (0,1mm) that it is, it is NOT perfectly flat looking like the good caps in the picture.. you have problems.

This problem is not just restricted to Motherboards it also applies to Power Supply Units too!


----------



## Done_Fishin (Oct 10, 2006)

just so you get the idea..

http://news.com.com/2300-1041-5940552.html


----------



## vvuuren (Nov 7, 2006)

Ok, I know what Capasitors are, I have had a quick look on my motherboard but I see no ODD looking Capasitors. So I dont think that is the problem.


----------



## Done_Fishin (Oct 10, 2006)

When the AGP is installed in the AGP socket but your monitor is connected to the onboard monitor, do you get a display?


----------



## vvuuren (Nov 7, 2006)

Yes. But when I plug the monitor into the graphics card (AGP port), I get nothing!


----------



## Done_Fishin (Oct 10, 2006)

So your Mobo isn't rediveting the graphics output to the graphics card.
If you were to have a Monitor on each card at the same time ONLY the onboard graphics card would give you a display.
I am suspecting either BIOS Configuration, BIOS, or mobo AGP output failure.
I need to find and download your mobo manual to see what other advice I can give.
I'll be back .. if you have a link to it post it here for me please


----------



## vvuuren (Nov 7, 2006)

Ok,

My thougths were that it must be an AGP port failure, since I have tried 2 different graphics cards in the port. 

Thank you for your help so far!


----------



## Done_Fishin (Oct 10, 2006)

according to the manual



> processor supports
> 
> 
> > AGP connector supports x1,x2,x4 only
> ...


----------



## Fr4665 (Nov 18, 2004)

what is the agp speed set to in the bios ? make sure its set to x4 and try it then. very nice job figuring that out done fishing.


----------



## vvuuren (Nov 7, 2006)

Ok, I get what you are saying. The thing is that my X1600 Pro graphics card was working fine in that AGP port for about 7 months and then all of a sudden when I turned on the PC there was nothing on the screen. I havent changed any settings in my BIOS or otherwise.


----------



## Fr4665 (Nov 18, 2004)

u didnt state before that u had used it for 7 months before without problems how should i know that ?

sometimes bioses reset wich could have also cause ur system to crash after 7months. it propably is the agp port that is dead.


----------



## vvuuren (Nov 7, 2006)

If you read the first post you'll see that I mentioned it worked fine and then all of a sudden it was dead! 
:wink:


So I guess if its the AGP the only thing I can do is get a new motherboard, huh?


----------



## Fr4665 (Nov 18, 2004)

sorry haha didnt kno how long it worked before should have asked ;-)

well yes from all the information u gave us and that the card worked for 7 months before in my opinion its definatly the motherboards agp slot. so the solution would be getting a new motherboard.


----------



## vvuuren (Nov 7, 2006)

Ah wel, guess I should then be starting to look for a new mobo! :sigh: 

Thanks very much for your help and advice, it is really appreciated! :wave:


----------



## Done_Fishin (Oct 10, 2006)

sorry a few messages got in here before I managed to answer ..

re bios changes ..above 

You don't always need to change the settings in BIOS, something can always trigger a change .. to get technical ... somewhere there is a memory address where a bit of data is stored. That data will be a 0 or a 1.
A bit of noise (electrical or radiating) could trigger a change in the stored charge and cause it to change state.


----------



## vvuuren (Nov 7, 2006)

Well, I have tried everything that I could and now have come to the conclusion that I need to buy a new motherboard.


----------



## vvuuren (Nov 7, 2006)

Ok, now that I have established that the AGP port is the prob, have any of you got any ideas as to what could be the cause of my AGP port so suddenly failing on me? 

It still looks fine on the outside, also it doesnt smell like it has burnt or anything.


----------



## Done_Fishin (Oct 10, 2006)

Pvisagi said:


> Ok, now that I have established that the AGP port is the prob, have any of you got any ideas as to what could be the cause of my AGP port so suddenly failing on me?
> 
> It still looks fine on the outside, also it doesnt smell like it has burnt or anything.












This is a block diagram of an Intel D850GB P4 motherboard. It shows the chipset being used that allows everything to communicate with the Processor.
I have coloured the AGP port Yellow for emphasis. The chipsests are frequently referred to the Northbridge Southbridge compents and require drivers to amke them work properly in conjunction with the CPU. Power Supply rails are NOT shown

Note that the AGP is controlled by the Northbridge part of the Chipset whilst the PCI bus is controlled by the Southbridge.

When you ask "have any of you got any ideas as to what could be the cause of my AGP port so suddenly failing on me? " this block diagram shows that, apart from Power Supply (which would be an on-board switch mode supply that converts one available voltage to the AGP voltage required to run the card) the common elements would be the Northbridge & CPU.
The CPU can easily be tested on another compatable motherboard, but not the Northbridge or Southbridge elements because these are what are known as BGA components. BGA stands for Ball Grid Array, and takes the name from the fact that the underside has no pins but just a lot of semi spherical solder "balls".
look it up on wikipedia
http://en.wikipedia.org/wiki/BGA

there are many types, shapes and sizes depending upon who designed them and where they are used
the underside may well look like this on your Mobo









One of the problems that BGA's have is ensuring quality of soldering on areas that cannot be seen. Usually this is done by X-ray equipment, but the procedure isn't perfect.
In spite of improved thermal conductance you will note that usually only one of the 2 bridges has a heatsink. This is the one that has the most work to do

http://en.wikipedia.org/wiki/Northbridge_(computing)


> The northbridge typically handles communications between the CPU, RAM, AGP or PCI Express, and the southbridge.



The most likely reason for failure, apart from manufacturing processes, is that it has overheated on the AGP section.
I note that more modern motherboards are being fitted with more powerful heatsinks and some with fan assemblies similar to those found on AGP cards.

from wikipedia


> Northbridge and overclocking
> The Northbridge plays an important part in how far a computer can be overclocked, as its frequency is used as a baseline for the CPU to establish its own operating frequency. In today's machines, the chip is becoming increasingly hotter as computers become faster. It is not unusual for the northbridge to now use some type of heatsink or active cooling.



BY looking at the block diagram above you can tell why, when the AGP is not working, we suggest using a PCI card instead. It uses the southbridge as a means to output the video display and can frequently help the Non-gamer to get their PC running again at an economical cost.

from whatis.com



> Northbridge
> 
> Northbridge is an Intel chipset that communicates with the computer processor and controls interaction with memory, the Peripheral Component Interconnect (PCI) bus, Level 2 cache, and all Accelerated Graphics Port (AGP) activities. Northbridge communicates with the processor using the frontside bus (FSB). Northbridge is one part of a two-part chipset called Northbridge/Southbridge. Southbridge handles the input/output (I/O) functions of the chipset.
> The Intel Hub Architecture (IHA) has replaced the Northbridge/Southbridge chipset. The IHA chipset also has two parts: the Graphics and AGP Memory Controller Hub (GMCH) and the I/O Controller Hub (ICH). The IHA architecture is used in Intel's 800 series chipsets, which is the first chipset architecture to move away from the Northbridge/Southbridge design.


----------



## vvuuren (Nov 7, 2006)

This all makes sense to me.

As my AGP port is max X4 whilst my graphics card is X8, I think that my AGP was overloaded and overworked by the graphics card and eventually gave in.

Thanx for shedding some light on the subject.

I'd rather buy a new mobo than use a PCI graphics card :4-thatsba


----------



## Done_Fishin (Oct 10, 2006)

Pvisagi said:


> This all makes sense to me.
> 
> As my AGP port is max X4 whilst my graphics card is X8, I think that my AGP was overloaded and overworked by the graphics card and eventually gave in.
> 
> ...


You're welcome

I can understand your reaoning about AGP/PCI preferences, however if you're NOT a gamer and just want to do basic computing and photo-editing stuff a PCI card would be a more economical solution, infact for you the most economical solution is to use the on-board card and increase you memory allocation to it at the cost of reduced availability for other resources.


----------



## vvuuren (Nov 7, 2006)

Thats just the thing, I AM A GAMER and I use my PC as an entertainment system. Therefore a PCI card simply wont do for me and my only option is to get another mobo asap.


----------

