WWAN ports

[yaccri]

My built-in Sierra WWAN cannot connect anymore.
I noticed that the Windows 'Device Manger' is not showing all the card ports.
The only ports are 4 UMTS ports. There were more ports before, and now they are missing.
The network I need to connect to is 3G.
The actual port on COM8 that was working well in the past disappeared.
'Scan for hardware changes' doesn't find more ports.
Is it a hardware problem?

WWAN was working fine before.
The card is Sierra MC8775 firmware H1_1_8_3MCAP.
Windows Vista Business, X61s.

Thank you

[Peak2Peak]

Try uninstalling & reinstalling all software associated with the WWAN card.

[yaccri]

I deleted all the occurrences of the Sierra card from the device manager and let Windows find new hardware. I didn't remove the drivers.
It didn't help.
Rebooting also didn't help.