BU-353 died?
I'm not sure what happened today.

I was sitting at a loading dock, not touching the computer. The GPS had a nice strong lock on it. When I started driving, the GPS stopped receiving a signal (or telling the computer where it was).

I uninstalled/reinstalled the drivers. I unplugged the puck. I moved the puck physically. I plugged the puck into different USB ports (including directly into the laptop).


The red light on the puck is solid red when I first power on the computer. Then, about 15 seconds later, it starts flashing, indicating that it has a satellite lock.

In the device manager, the port is showing as Comm 3. However, when I try to open this port with any GPS software, it says that the port doesn't exist. I ran the Prolific GPSInfo utility and it doesn't see it either.

I also tried plugging in my backup receiver, which is an older Microsoft USB receiver from S & T 2005. It lights up, but gets no data either.

Also, I tried uninstalling the ports (for both) from XP's safe mode.


I've already ordered a new puck, but any clues to what could be wrong?

Right now I'm using the GPS port on my Sprint USB data card. It gets a lock once in awhile, but it definitely can't be depended on.

I found this info on the USGlobalSat forum's and it seems to have fixed it:
Attempt the following:
a.) First, (re)connect the GPS receiver to your USB port.
b.) From your START button, select CONTROL PANEL -> DEVICE MANAGER -> Ports -> Prolific USB-to-Serial Comm Port (Com X) -> Port Settings ->Advanced -> COM Port Number. From the drop-down menu select the desired communication port value. Followed by a double-click on the "Ok" radio button. Lastly, override the Communication Port already in use notification.
The above actions should reconfigure the GPS' data port.
Good info to know!!!

Now I'll have a good spare also - LOL
My experience with the Prolific driver is it requires setting up on each USB port and gives a different COM port each time. Unless you had already set it up on each port, you should have got a "Found New Hardware' message when you changed the GPS to a different USB port. If not, the GPS is faulty and Windows didn't detect it.

The S&T one may just need a recharge or to find itself. Or maybe the internal battery is toast.

I'm thinking now that my computer messed up, not the receiver.

After I had the receiver going for about 12 hours (give or take), it died again. So, figuring that it couldn't hurt, I formatted my laptop and reinstalled everything. So far, it's looking ok. I'll leave the laptop hooked to the GPS and running for the weekend to see if it drops out again.

As far as the S & T receiver, it's a USB receiver, not a bluetooth. I'll plug it in sometime this weekend also to see if it's dead or not.
Ok - something goofy is going on with my system and I have no clue what it could be.

This weekend I reformatted/reinstalled everything. I hooked my original BU-353 up and it held a perfect signal for about 48hrs sitting inside the house, with no line-of-site whatsoever.

I put the laptop in the truck and it sat there and held a perfect signal for about 8hrs before I left yesterday.

As SOON as I started driving, I went from having a lock on 8 satellites to only getting a lock on 2 or 3 at a time. I switched to a brand new Microsoft USB receiver, exact same thing. I switched to my old Microsoft USB receiver, again, exact same thing.

I then stopped and re-downloaded/re-installed the drivers for the Prolific receiver. No luck - same thing is happening.

When I parked last night, I again went from having a 2-3 satellite lock to 7-9 locked.

Any clues to what could be going on?
Marvin Hlavac
It could be some RF interference. Could you improve the location of the GPS receiver? Place it closer to the window? Place it outside the truck for testing purposes? Where is it now? LCD screen may emit signals that may interfere with GPS receivers, if too close. Are you using too long USB extension cable? Are you using (unpowered) USB hub?
I've always had the receiver either sitting on the center of the dash or attached to the passenger side door. It was originally hooked through an unpowered hub.

My last try was putting the receiver in the rear-side window of the truck with the receiver hooked directly to the laptop - getting the same results.
Marvin Hlavac
Instead of plugging the receiver directly into your laptop, try a short (not longer than 6 feet) USB extension cable. Avoid a USB hub, at least for the testing purposes. Also, try not using any computer accessories during testing (unplug them all).
What's driving me nuts is that nothing has changed in my setup. I've got the exact same hardware located in the exact same location running the exact same software as I've always ran.

The only extension cable I have with me at the moment is a 16' active extension cable.
Marvin Hlavac
Try to at least experiment with different location of the GPS receiver. Also, try to unplug everything unnecessary from USB ports.
I just tried:

Unhooked everything from the laptop except for the GPS receiver (I tried 2). I mounted the GPS receiver on the hood of the truck (all the way in the front, centered) - I used my long active ext cable for this.

Sitting still, I had 8 of 9 satellites with a strong lock.
As soon as I started moving, they dropped to 2-3 which were switching constantly. When I hit about 35mph, I lose all satellites.
As soon as I slow down, they start coming back (2-3 of them again). When I stop, I instantly go back to 8 or 9.

Again, this happens with 2 different receivers.
Marvin Hlavac
I would try a plain, short USB cable now, but since you don't have any with you at the moment, you can't test that. Try to disconnect your power supply. use the laptop just on it's own battery power, to see if the issue goes away.
Running on battery won't work. My battery gave up the ghost about a year and a half ago ;-)

Dunno - I'm starting to think that it's getting about time to replace the laptop.
Ken in Regina
Is there any difference with the engine running and the engine switched off? How about with the engine idling versus revving up (still without the vehicle moving)?

I'm just following up on Marvin's thought about electrical interference. The GPS signals are so weak that it doesn't take much to wash them out. It would be good to establish whether it's related to engine running and/or revving without vehicle motion or whether it's related to movement, as you seem to be assuming at this point.

You might have a perfect excuse to get a new truck rather than a new laptop, depending upon the source of the problem.

Sorry if you've already tested and eliminated this possibility.

Marvin Hlavac
...also, along the same lines as Ken... Has any recent work been done on the truck itself? Are you using the same truck as before? Have you recently bought a new power inverter? Have you recently changed how the power goes to your laptop? Is the inverter plugged now to a different outlet?

Instead of placing the GPS on the hood (for testing), place it on the roof (further away from the engine).

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