Clear all

[Solved] Trimble 4000 SSI week rollover

7 Posts
6 Users
Posts: 4
Member Member
Topic starter

I have a few old GPS receivers but the week rollover problem hit them, I really want to fix them 

I would like dear friends to tell me where I can find a firmware solution to this problem???

if there is one,

and how is the procedure to install it.

Thank you!!

Posted : March 24, 2021 7:15 pm
Posts: 9329
Member Member

Three options can be found by searching this forum.

1. Fixweek has been written by a forum member to correct the .dat file. Be sure it is intended to run on the Windows version you use, because I think it crashed mine with an update to a .dll so I had to use the Win install disk to do a repair.

2. I use the free teqc program from the UNAVCO site to convert from .dat to RINEX format and specify the GPS week number.

3. Someone has reverse engineered the software and posted a link to a version with a fix. I have not seen any reports of others success or failure installing it. I haven't risked breaking what I have that works.

Posted : March 25, 2021 6:37 am
vick, vick and vick reacted
Posts: 9329
Member Member

4. And possibly best -- Jim Frame pointed out in a previous post that Trimble has a tool that worked.  I tried it and I think it does the essential job.  I think it leaves a minor discrepancy in the annotation so that if I try to analyze the file wit teqc, it gives me a bunch of messages about differing week, but the results look ok.

Posted : March 25, 2021 8:43 am
vick, vick and vick reacted

Get the 2023 SurveyorConnect Wall Calendar

Jim Frame
Posts: 7045
Member Member

FYI, I installed the firmware that robots (I think that's his username) modified in one of my receivers, and it works well. What he did is black magic from my perspective,l; I'm totally in awe of his skill.

Posted : March 25, 2021 11:55 am
syazone01, vick, syazone01 and 3 people reacted
Posts: 76
Member Member


i have made my modifications public. In this repository you will find firmwares which i have modified to work with recent rollover. Have fun!

Posted : March 25, 2021 1:04 pm
syazone01, vick, Miguel_Fierro_Tuca and 9 people reacted
Posts: 1
Regular Member Member

@robots I was able to update two 4700s I bought off of eBay that had Firmware Version 1.30. I bought one without a radio for $70 and one with a radio for $120. Varous cables, a radio, etc. etc. I had an RTK system for about $2500. Thank you for sharing! 

I used these receivers back in the early 2000s and other than all of the cables they are reliable and accurate units. I retired from the state and started my own business in May. Instead of spending $100k plus on a GPS system, I thought I'd get a 4700 system going. RTK works perfectly with the old firmware. I really wanted to report accurate coordinate values on my surveys and I am grateful I found your fix.

A couple of installation notes (the installation instructions are clear, this just works in my head and may help others):

I am running a Windoze XP in virtual machine in Linux (Debian 11) with a serial to USB converter. The files do not download property in Linux from GitHub using the virtual machine. I have a Windoze 10 box that I downloaded the files to but, used an old Windoze XP box to flash the devices because the Windoze 10 box does not have a physical 9-pin serial port. It is my experience you will need the physical 9-pin port on your computer.

You will need WinFlash .

This might help understand what is happening (it works in my head). Once "trim=130.reg" is imported into the registry, "FirmwarePath" points to "C:\Program Files\Trimble\WinFlash\Firmware\130may23-alt.47s". Copy "130may23-alt.47s" to that location on your machine.


When WinFlash is launched, select "4700 Receiver";

Then select "GPS software upgrade";


 Then select "4700 Firmware v1.30-fixed;

WinFlash will do its thing. Make sure you have a reliable power source connected to your receiver. A window will pop up once the flash is complete saying the flash was successful and asks if you want to update the radio. I went ahead and tried to update the receiver without a radio and WinFlash reported there was no radio. The receiver with the radio updated successfully to version 1.43. On the receiver without a radio, WinFlash said the firmware was already installed and did I want to install this version anyway and I said yes. It updated fine.

I collected 30 minutes of static two days ago and sent the .dat file to OPUS today and it returned a result. This is excellent news. 

Thank you again.


edit: words and words

This post was modified 2 months ago 2 times by 60lpsdf250
Posted : October 2, 2022 9:19 am
mike1202 reacted

Get the 2023 SurveyorConnect Wall Calendar

Posts: 142
Member Member


Hi Jim, 

I have three Trimble 4000 SSi units.  They may be useful this winter for a static project. BUT, these haven't been used in years.  I also have a nice 4700 that hasn't been used.  It looks like these units will have to have a firmware upgrade to work ??  Have you had luck with this ?   

Thank you Jim 

Dave Harris 

Posted : October 26, 2022 8:55 am