HP Integrated Bluetooth module upgrade on old NX7400 notebook

[Janux]

Yes, I'm one of those crazy old people, computer maniacs, who likes to revive vintage computers!
I have recently reactivated an old (very old) notebook that I am fond of because this HP Compaq NX7400 was my first personal notebook that I bought in 2006 together with the EN488AA docking station.

About 10 years ago I had replaced the Intel Core Solo T1300 CPU (Centrino at 1667 MHz - Yonah) with an Intel Core 2 Duo T7600 (2333 MHz - Merom), mounted two 2 GB DDR2 667MHz ram modules, replaced the hard disk with a 128 GB Kingston SSD, mounted a Samsung HM250JI (PATA) hard disk in the CD-Rom drive compartment, then after updating the Bios to version F.0E (without whitelist) I installed an Intel dual band WiFi Link 5300 card.
With these updates and 64-Bit Windows 7 at the time the computer was (and still is now) usable for surfing the web and for managing emails and doing some small work with the Microsoft Office suite while I was away from home for work, or at home without turning on my desktop computer.

A few days ago, despite the limitations imposed by Microsoft, I even managed to install Windows 11 and now the notebook works in a way that I never even imagined.

Now I would need to update the Bluetooth device to be able to use the latest bluetooh devices that require at least version 4.0 or LMP 6.x.
For those unfamiliar with it, I would like to point out that this notebook model has a separate bluetooth card called "HP Integrated Bluetooth module" (Broadcom BCM92045NMD, HP P/N 379191-001) which cannot be replaced with a newer one, at least this is what I understand from numerous searches on the web.

I then tried replacing the Intel 5300 WiFi card with a WiFi/Bluetooth combo card. I have tried both a Broadcom BCM943228HMB (802.11n) and an Intel AC7260 (using a half-size/full-size Mini PCIe adapter) in both cases the WiFi works wonders and with the Intel 7260 it even reaches 500 Mbps, not bad for a 16 year old notebook!

Unfortunately, the Bluetooth device on the two Mini PCIe cards is not seen by the operating system.
I read on a schematic that the two USB connections D + and D- of the Mini PCIe slot (pins 36 and 38) are not connected to the PCI BUS (I don't know how true this is).

In conclusion, I think that it is not possible to upgrade the internal Bluetooth but that it is necessary to use a USB key to be inserted in one of the 3 available USB ports.

Am I wrong something or is it really so?

Note at the bottom.
For the avoidance of doubt I want to make a long clarification: I did not do it to save money! We have three other recent HP notebooks and two HP desktops at home. I did it simply because I don't want to throw away years of memories and I don't even like keeping it in the cellar to collect dust. Aesthetically and mechanically, the notebook is like new, thanks also to the quality of the HP plastics of the time, moreover, apart from the first two years, I have always used it as a spare computer and rarely on the move. This notebook was masterfully crafted by HP and the service documentation was and still remains the best I have seen in 40 years as an electronics and computer technician. This small computer allowed me to practice hardware, 56K modem connections, wired and wireless LANs, and network internet sharing in the days of Windows XP and Windows 98. For this reason I am grateful to him, because he allowed me to transform what was previously just a hobby into a pleasant and rewarding job.

Thanks for reading this far and for any answers.
(Sorry for my bad English but I translated with Google)

[Paul_Tikkanen]

Hi:

For the Intel 7260, have you tried this mod?

That would be the only suggestion I can offer.

Intel 7260 Wifi/Bluetooth Card Fix - YouTube

[Janux]

Thank you Paul,

But that solution of isolating PINs 20 (W_DISABLE) and 51 (Reserved) of the mini PCIe module, from what I understand only works on notebooks that originally mount a half-size card and do not have a separate bluetooth card. Usually these notebooks do not have a dedicated switch to turn on/off the wireless connections but a combination of keyboard keys is used.

On these computers the bluetooth module is not recognized by Windows but in any case even if it appears as an unknown device in the Windows device manager. In my case I have a full-size Mini PCIe slot, when the notebook was produced the Mini PCIe combo cards with WiFi and Bluetooth did not yet exist, and it seems that on these older computers, bluetooth does not appear right in the device manager, therefore I assume that what I wrote above is true, that is, older notebooks, which originally came with a full-size Mini PCIe card, do not have USB data pins connected to the PCI bus. I can try to tape the two pins 20 and 51 but I doubt it can solve my problem.

Another possible solution (from retired electronic man 😊) would be to cut the 8-wire cable that connects the bluetooth module to the motherboard you need only 4 of these VCC, D +, D- and GND, solder them on a female USB socket for pcb, insert in this a dogle BT 4.0 and hide everything in the compartment of the current bluetooh module.
The problem is that from the motherboard on pin 8 to power the Broadcom bluetooth module comes only 3.3V while a USB dongle requires 5V. I could take them from the adjacent USB port by means of a wire soldered under the PCB but I am forced to completely disassemble the computer. I don't know if it's worth it.

[Paul_Tikkanen]

You're very welcome.

I agree.

Doing all that work is probably not worth it.

If you don't use BT all that often, the best thing to do would be to use a USB BT 5.0 adapter.

[Janux]

Thinking about it well, it is not enough to power the USB stick with 5V, you should insert a level adapter from USB to TTL on the D + and D- signals, otherwise the risk is to burn the motherboard expecting a TTL voltage level of 3, 3 V and not 5 V.

Thanks for the discussion, I've cleared my mind! 😊

[Paul_Tikkanen]

Anytime.

I had the nc6400 for many years and installed W10 on it.

I couldn't install W11 because the T2400 processor only supported 32-bit operating systems.

I finally donated it to the local goodwill store in the hope that someone else could enjoy it.

I left the Intel 535 120 GB SSD installed, otherwise it would have been painfully slow.

I had also upgraded the memory to the max of 2 x 2 GB.

When I think of the range of operating systems that notebook could run...from Windows 2000>Windows 11, I am amazed.

The nc6400 was equivalent to your notebook, but it has the 14.1" 16:9 display.

[Janux]

Yes, I know the NC6400 very well, I had a corporate one, the company I worked for supplied it to employees and I was in charge of the configuration and maintenance then.
Great machines, well built and with quality materials.