Leadtek 9537 No Flashing Green ..Won't Receive Satellites

Vic

I have owned my Leadtek 9537 about a month now, bought it on Ebay and it has been working fine. When I switched it on on Moday evening it would not lock on to a fix, i.e the Green LED would not flash.

I thought that maybe the battery was low so I tried it again after charging it but it was the same. The Bluetooth connection is fine, If I connect to it using hyperterminal in Windows I can see the NMEA sentences being produced from the unit but they do not change. Using Winfast navigator I sent a cold reset to the device but still no Sat signal levels are showing.

Does anyone have any I deas of what else I can try? I am thinking that maybe the front end of the units receiver has been damaged by being in proximity to a mobile phone, though I always make a point of carrying my phone and BT GPS in separate pockets for this very reason.

I am hoping that the unit has just got itself locked into some strange mode which maybe needs a controlled reset.

Vic

lbendlin · Posted: Wed Mar 02, 2005 5:59 pm Post subject:

If your warranty has expired already you can open it up and disconnect the battery for a while.

Otherwise send it in for a replacement.

Mobile phones are not powerful enough to harm other circuitry. You need a solid EMP to do that.
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Vic · Posted: Wed Mar 02, 2005 6:09 pm Post subject:

I have already removed the battery (it is a replaceable mobile phone type) for an overnight period. Do I need to try for longer?

I was looking at getting an external antenna and trying to see if that would work.

I really would need a working GPS by this coming weekend. Driving

hanoudi · Occasional Visitor Joined: Mar 03, 2005 Posts: 11

I have the exact same problem after 2 months of use...have you had any luck with it?

Do you know how to contact leadtek for warranty?

samos29 · Occasional Visitor Joined: Mar 23, 2005 Posts: 2

Hi,

I have exactly the same problem than Vic.

Has your problem been resolved ?

Thank you

Vic · Posted: Thu Mar 24, 2005 9:07 am Post subject:

No It hasn't Crying or Very sad

Every attempt to contact Leadtek has failed. Emails sent to any of their addresses doesn't even seem to produce a delivery receipt, let alone a reply! I've more or less given up trying to get a warranty repair on this. Anyone else thinking of buying Leadtek take note.

If you care to look in the polls section of this forum, this fault appears to be very common across bluetooth GPS's (nearly 50% Exclamation

) In that the internal Antenna or its associated amplifiers fail in my opinion due to external signal /spikes or possibly from being stored close to a mobile phone.

I am still awaiting an external antenna to try that. Suppliers have let me down, hopefully it will arrive by the end of the week. If that works, the device will probably become a permanent fit in my car. I could even then attribute the fault to a couple of discreet components on the GPS PCB which if I could obtain them (will maybe post pics here) as an electronics engineer I could even repair it myself!

Vic · Posted: Sat Mar 26, 2005 4:02 pm Post subject: WORKS ON EXTERNAL ANTENNA!!

I received the external antenna today, plugged it in and within a minute it had received a Fix.

The Fault? the external antenna working has helped me narrow it down to a very small area!

This is a picture of the RF Front end part of my 9537. The patch aerial connects at the large solder blob top left. The signal is filtered via L2, L3 and C42. I reckon these are most likely not up to the job and rf/emc spikes etc are passing through and damaging U14 which is probably a low noise amplifier.

The external Antenna connects at the second brass bit at the far bottom right of the picture.

My aim now is to replace and identify U14, marked "BRs" I think identifying and obtaining it may be harder than the soldering!

samos29 · Occasional Visitor Joined: Mar 23, 2005 Posts: 2

Sorry, but I'm french and my english is quite poor Confused

(you made a good explaination, but too technical for me !!)

To conclude, does your GPS work now with the antenna or not ?

Thank you

Vic · Posted: Sat Mar 26, 2005 6:27 pm Post subject:

Yes, it works with an external Antenna only.

Vic

Vic · Posted: Mon Mar 28, 2005 12:09 pm Post subject:

I have done some research on the suspected failed component and have discovered what it is. The component is a BGA622 Low noise amplifier connected via a filter circuit directly to the aerial. I’ve identified the component and am trying to source a replacement.

Having scoured the net for datasheets for the amplifier, and looking through circuit applications, I have discovered a bulletin from Infineon, the manufacturer of the amplifier which basically states that it is easily destroyed by electrostatic discharges. As low as 300v which is nothing in static terms, can blow or weaken it! The bulletin goes on to suggest a protection circuit which is not used in the Leadtek GPS. The flat square antenna close to the case of the unit will easily collect static, Basically the design of the GPS is fundamentally flawed!. I suggest you treat yours with kid gloves. Store it and use it in an ESD protection bag.

Vic · Posted: Wed Jun 01, 2005 7:57 pm Post subject: Fixed It!!

A friend of mine managed to acquire a few samples of BGA 622 from a supplier. Soldering in the replacement was easier than removing the old chip. My GPS unit is now working well again on its internal antenna. Success! ..no thanks to Leadtek!

Vic

dogboy · Occasional Visitor Joined: Jul 08, 2005 Posts: 2

:D Hi I wonder if you can tell me what sort of external antenna you used with your leadtek? Do you know what the connection is called that the antenna uses to plug into the leadtek. I think it is an RF connection but I cannot find an antenna that has an RF connection.

Thanks for any help Confused

Vic · Posted: Sat Jul 09, 2005 11:01 am Post subject:

The connector is called an MMCX connector. THese antennas are available on Ebay.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&category=14946&item=5787165249&rd=1 as an example

Vic

dogboy · Occasional Visitor Joined: Jul 08, 2005 Posts: 2

Thanks for that Vic,
I will buy one just to be on the safe side although I have not had any problems to date. Off to France in a couple of weeks, should it breakdown I would have to resort to the wife navigating again! (Does not bear thinking about).

korndog · Posted: Sat Jan 14, 2006 2:34 pm Post subject: Re: Fixed It!!

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