If you have ProMark 3, MobileMapper CX or MobileMapper CE receivers…
…sit down, grab a beer and take a deep breath….
We (iGage) believe that the internal battery backup batteries in these receivers are reaching the end-of-life now.
First, it is not the end of the world. We can replace the batteries for $150 for a single receiver or $250 for two receivers. [ Click Here For More Info ]
Okay, take another breath now and I will share the details:
We have gotten complaints that these receivers are taking forever to begin tracking SV’s
We have gotten complaints that these receivers are not detecting the external antenna (see below for additional information)
We have gotten complaints that receivers are loosing the date/time (well actually this has ALWAYS been an issue, but it seems worse now)
I think that the receivers are losing the GPS ephemeris when the main battery is removed from the receiver for more than a minute or two. This has been verified by measuring the voltage on the backup batteries (actually super caps):
The voltage is 3 volts when the batteries are new, on the five receivers that I opened and checked this week, the voltage was 0.4 Volts or less.
We replaced the batteries in a couple of units and sure enough, they track SV’s in a minute or two after having batteries removed for a while.
You can get around the lost ephemeris issue by turning the receivers on 15-minutes before you need to use them and let them acquire SV’s with the internal antenna while you are driving to the job. You can also keep a charged main battery in the receiver and swap them quickly when exchanging.
But there is a danger in not replacing the batteries: they can leak acid which can eat the adjoining traces. Luckily the batteries are not too big, so they don’t leak much.
More on Not Detecting External Antenna
If you are encountering problems with the PM3 or MMCX not detecting the external antenna, remember that the antenna status is not correctly reported until after the receiver tracks enough SV’s to get a position:
So even if an external antenna is plugged in, it will not be reported until AFTER a position is displayed.
If your battery is dead and you have to wait for 5-minutes for the PM3 to track SV’s, then it may appear that the external antenna is faulty. Not so.
iG GPS 
Yep, and my PM3 is working great now, Thanks
my CX with Fast survey has stopped saving the points. when the unit is turned off the surveyed points are gone. ideas??
The only places on a CX that are non-volatile are “My Device” (and subfolders) and the SD Card.
You are probably storing jobs under “My Documents” which definitely is not backed up.
Just change to any folder under “My Device” and you will be fine.
Mark
I’m still having issues with one PM3 not recognizing the antenna. I know it’s with the receiver and not the antenna by process of elimination. I can sometimes get the PM3 to recognize the antenna with on cable for a few minutes, but then the dreaded “Antenna not connected, logging can not take place”.
Any ideas how this can be fixed?
Hello I am from argentina and I have 2 promark 3 with problems of battery internal, where them can get or which battery can serve as replacement. Thanks a lot
checkout https://blog.ashgps.com/2016/09/07/promark-3-batteries/
Good night.
I am a Portuguese citizen and I have a couple of promark 3 receivers, one of them has now decided not to start, the screen light turns on but does not start. Open it and the backup battery is corroded. Do you think the problem may come from there, or is it a software or hardware problem?
Thank you.
Best regards.
Rui
I don’t think it would keep it from starting, but it might be worth a try.
Try to start with unplugged from external power. Some of the PM3’s would have a very difficult time starting when plugged into external power.
Well, then I do not know what’s happening, the pmk3 receivers spent some time with the batteries discharged, but only that one is in trouble, the other is working well. The initialization was done with the battery, it was not made connected to the electric current. When I press the power button, the screen will light but will not start. Here in Portugal, unfortunately, I do not think there is anybody who can assist with this equipment.