Batboard

I have a Maratrac Lowband radio that we programmed with no issues, about 2 months after programming we decided to try changing a setting and ended up with a error #5 when the RSS tried to communicate with the radio. We tried multiple cables, one factory and one aftermarket - both setups program other low band Maratracs just not this one. We checked all pins for cold solder joints and rang them out - all seem connected well. We get the same voltage (4.93) at the programming pin (7) in the radio. It just doesn't seem to be found by the software. We also reinstalled the software with a fresh installation, still no communications. Any ideas?? Its powered by a 50 AMP supply and is feeding a BR-4 Antenna, its also utilizing a brand new cable to an advanced control head. I am at a complete loss. Thanks in advance.

- Rob

CORRECTION, Its ERROR 2...

Is it by any chance one of the old logic boards with the DALLAS memory chip?

Not sure, where am I looking to find that info out? And if so, what would I do to remedy it? Thanks.

- Rob

Look under the shield on the logic board.
First clue will be that the logic board will be red instead of green.
HLN5402A
Under that shield there will be two rectangular IC's one is the 27014 or other EPROM the other will be the DALLAS "non-volotile SRAM".
Those old DALLAS chips actually had a small alkaline battery built in to hold the variables of your programming.
Channel info, tones, etc.
The EPROM has the radio operating system and those are pretty much a many decades kind of device.
The DALLAS chips were more like 20 years.
If that baby has gone dead, you need a new logic board.
I have seen a few starting to do this, including the similar 800 mhz Type 1 trunking Maxtracs.
I have a dead Lowband Maratrac board in front of me as I type.
But, if you have substituted pretty much everything else, that is likely the problem.
Since it is a Lowband radio, it is probably worth finding a salvaged logic board and fixing it.
I hokeyed around with a blanked Maxtrac board and fixed mine a couple of years ago.
Using a logic board with the newer ATMEL 28C16 family that was used on everything except the oldest Maxtrac/Maratrac/Radius/M400 family.
I can't recall for sure, but it seems to me it was a case of blanking an old Maxtrac 5 pin logic board.
Extend ( or move ) the logic board to RF board connecting pins.
Removed the Maratrac EPROM and put it in the now blank old Maxtrac board.
Re-initialize the "new" board in the Maratrac with either Maratrac or M400 RSS.
It would be best to verify the pinouts on both radios, but my feeble memory tells me that is what I did.
If it isn't the DALLAS chip, then it is just some other failure.
Remove all boards, clean up all interconnections and grounds, then cross your fingers.
Those are still a darn good radio for Lowband.

Sorry for the late reply. Its an ATMEL chipset. Working on pulling it apart and cleaning it. Thanks, will keep you updated!

- Rob

Pulled boards apart, cleaned connections and re-assembled. It still won't program. Works great where it is, but I can't read or write to codeplug. We are using a RIB programmer with the correct software. We tried two different motorola RIBS and both work on our other Maratracs but not on this one. Any other ideas? Thanks.

- Rob

The programming line on the logic board is bi-directional. It is clamped with VR806, a 10V zener diode. If this shorts out, you won't be able to read or write to the radio. Data sent by the computer/RIB goes into U601b which buffers it and feeds it to the microprocessor, U802 pin 20, RxData. The microprocessor sends data out U802 pin 21, TxDATA. It goes through a plated jumper JU806. It then uses Q808 and Q809, both PNP transistors, to drive the programming line and send data to the RIB/computer. A fault in any of these components will break the signal path and the radio will either not see data from the RIB or not be able to send a response back to the RIB. This lack of response to the software gives you Error 2. The signal paths would need to be followed with an oscilloscope and the faulty parts replaced, or the entire logic board would need to be replaced, which means a full alignment.

If someone fed an excessive voltage into the programming pin, this could either cause VR806 to short out, thus killing communications, or it could destroy Q808 or Q809. Any of these are easy to replace as they're all on the top surface of the logic board. U806 would probably survive, but it too is easy to replace.

There's not much to it. A good technician should be able to repair the board. The problem may be finding one near you.

Bob M.