Hi all,

I am tasked with repairing a DT80-2 which suffered water and ant damage. I have pretty much cleaned it up (except for the flat Lithium Battery which is awaiting a replacement) and replaced corroded DB9 and other components. The device powers up and I have upgraded the firmware. I can connect to it OK via USB or Ethernet.

However on power up I get a Self Test Failed message and dEX reports:
TEST report generated at 2018/08/31,11:55:39
dataTaker 80 Version 9.20.8942 Flash 2017/03/28 10:40:21

Product: DT80-2
Serial Number: 086936

VEXT 12.1 V
VBAT (6V) 6.74 V PASS
IBAT +9 mA PASS
VSYS 7.05 V PASS
VLITH (3.6V) 0.13 V FAIL
VDD (3.3V) 3.28 V PASS
VANA (3.8V) 0.06 V FAIL
VRELAY (4.5V) 4.50 V PASS

VREF (2.5V) 2499.66 mV PASS
Ics I 0.21274 mA PASS
Ics II 2.5647 mA PASS
Vos diff 7.1 uV PASS
Vos 3W I 144.3 uV PASS
Vos 3W II -300.5 uV PASS
Vos shunt -33.2 uV PASS
Vos + 8.8 uV PASS
Vos - 5.5 uV PASS
Vos 8.0 uV PASS
Vos # -66.0 uV PASS
Vos diff atten 71.1 uV PASS
Vos + atten 70.7 uV PASS
Vos - atten 71.1 uV PASS
Vos atten 71.1 uV PASS
Term. factor 1.00470 PASS
Shunt (100R) 99.844 Ohm PASS
CMRR 113.9 dB PASS

Overall health FAIL

The VLITH fail is expected of course, but how do I address and correct the VANA fail condition? Is it a setting or a physical connection? I haven't found a reference to this in the manual/s yet.

Thanks in advance for any help or suggestions. Please be gentle , I am new to the forum but expect I might be back here as I progress this repair job.

Steve W

Good afternoon Stevo

Were all the inputs disconnected when you ran the test command?
If not then try again with everything disconnected if it still fails then it will need to be returned for repair.

Cheers

Roger

Thanks for the response Roger.

Yes, there was nothing left connected to the DT80 when I ran the test.

I'll have to check on the history, but I believe this was returned from an agent here in Brisbane with the advice that it was working OK. But it can't have been - there was a lot of ant debris in the unit, couldn't power it on at all, the DB9 was holding on by a single pin (all others having corroded away, including the mounting pins), the internal battery was dead flat (0.2V), as was the internal lithium battery. Data on the display was corrupted/garbled, and on connecting to it after the repairs DTUSB didn't recognise the device, what data I could see with DeTransfer advised that an upgrade was required. I persevered and got the the unit upgraded to V2.90 OK but that seems to have wiped any existing programming. What programming I could see beforehand was pretty corrupted anyway and I tried unsuccessfully to back up/copy that data. At the moment there are no schedules showing other than a blank Schedule A.

Since the firmware upgrade to V9.20 things the unit seems to work and I have experimented with a few simple queries and test commands from DEX to check that process. But the Self Test Fail and the associated VANA error makes me cautious. One test I tried was turning the output relay ON/OFF (we want to power an external sensor) using "1RELAY=1 or 0" but that didn't seem to work when checking across RELAY A & B with a DMM. Switching the 12V output on/off using "PWR112V = 1 or 0" does work.

I haven't got too much further since I posted prior to our weekend.

If I have to return it for repair, where does it go to?

Good day Stevo,

Ants are bad news. Their bodies are quite acidic and will corrode PCB's.
Contact your dataTaker distributor for details on how to return you logger, there is a list on the dataTaker web site.
If you are in Queensland it will be Pacific Data Systems.
Once back at the repair facility they will evaluate the extent of the damage to see if it can be repaired.

Cheers

Roger

Ants are definitely bad news.. but the DT seems to have cleaned up OK and is sort of working, just a few issues lie VANA
PDS were the ones that gave the device a clean bill of health after a couple of months but perhaps not much action, screws holding the case together were so corroded that I had to drill them out, so the case had never been apart in that time

I'll have to see what the company want me to do from this point if it needs to go back to get this VANA issue repaired. What does VANA actually do? is it critical to any measurements, reliability or actions? where is it used?

Thanks for your advice so far

Stevo

Hi Stevo,

VANA is the source for powering up DC-to DC converter (5V source output), the failure come from voltage regulator (which failed to give 3.8 V output).
It should not affect other components.
As long as you are not using 5V source, you can keep using the logger.

Best regards,
Rudy Gunawan

Thanks for the response Rudy.

I am not planning on using the 5V source.. but your reply explains why I can't turn toggle 5V/12V. But I can control 12V quite OK and that is all I need to do at present.

Would VANA also impact the relay operation by any chance? I can't get that to function either, but everything else seems to be ok.

Stevo

Look for the 1763 ICs on the lower PCB. There's two on the top PCB too.

Check the voltage on Pin 8(Input) and Pin 5 enable/shdn. Pin 1 is the output.

The relays should be okay. VRELAY (4.5V) 4.50 V PASS
Michael Hampson
Lontek

Thanks Michael,

Component ID is U158 for LT1763.

Best regards,
Rudy Gunawan