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com ports do not work

By kevin_madenyika ·
i am currently working on a computer that has an INTEL CA810 motherboard and the com ports do not work.i can't figure out what might the problem.the major issue is that the machine can not detect the presenec of a serial device in my case a modem and a serial mouse.can you help me please and i need your feedback a.s.a.p. and the intel site does not solutions since they don't make the boards anymore.

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by carlos.nino In reply to com ports do not work

You didn't specify your Operating System. Anyway, this board supports 2 com ports via a header. When a header is connected to the board, chances are you have to make a jumper/switch adjustment. Check with your manual if this adjustment was made correctly.

If it were driver issue, check here:


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by dmiles In reply to com ports do not work

First of all, make sure that you are testing the port with a simple device that you know works. For example, a plain serial mouse is the best device to use for testing a COM port since it is easy to know if it is working properly or not. Test the device on another system to rule out the device as a problem.
Test the COM1 port first, since it is the least likely one to have a configuration problem or resource conflict. If COM1 is working and the others aren't, this may be due to a resource conflict, although it could just be that the software setup for the other port(s) is incorrect.
Check your BIOS settings to ensure that the COM port is enabled. If it is disabled at the BIOS level then of course, it will not work.
Check the setup of the software being used to drive the device. Some devices will only work properly if they are set to the correct parameters such as speed (baud rate), stop bits, parity, etc. Use simple software when testing ports, to eliminate complicating factors.
Check the external connections to make sure they are not loose. Check the cables running from the port to the motherboard headers to make sure they are tight as well.

There may be a resource conflict with the COM port. In particular, if you are trying to use devices on COM1 and COM3 simultaneously, or COM2 and COM4 simultaneously, and you didn't change the default IRQ settings for COM3 or COM4, then you probably have a conflict because the pairs I just mentioned share an IRQ setting by default. See here for more.
In order to avoid resource conflicts, it often makes sense for the resource settings of the COM3 and COM4 ports to be changed from the default standards. However, when you change the IRQ setting for a COM port, you sometimes have to tell your software what you have done, or it will not work properly.

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by Curacao_Dejavu In reply to com ports do not work

start with checking in the bios if the com ports are enabled or not.
you can check also in the bios to use optimal settings or default settings.
In the os (which one ?) check if there are no other devices using the com ports.
The less device you have physically installed the better (for troubleshooting purposes).
try to start only with the serial mouse (did you verify that the serial mouse is working well with another system ?)

post a note on how you are proceding ?


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by PaulP In reply to com ports do not work

COM ports can also be disabled in the BIOS. Check there.

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by Mark In reply to com ports do not work

Step 1. Check the BIOS to be sure the ports are enabled.

Step 2. Check the ports with a loop back plug in DOS Mode with software like QTPRO.

Once working in DOS mode, check in Windows. If it works in DOS and not Windows, let me know and I'll give you some steps to check there. Start though by installing the Intel Chipset Drivers from their website. Even though they don't make the board anymore, they have a general chipset driver that needs to be installed in windows to ensure the OS can talk to the devices properly.

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by Graham.P.Phillips In reply to com ports do not work

This is quite likely due to the need of a BIOS upgrade.

Check your current BIOS version and do a search on something like GOOGLE for your make motherboard.

I found this below, but please do all the necessary checks first.


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