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U6 power supply problem...


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#1 nono33z

nono33z
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Posted 27 March 2013 - 08:29 AM

Hi, I had a problem with the external power supply, with the U6. and I think the component marked U21? (see photo in attachement) is dead, how to replace it? by what reference? is there a solution? Thanks in advance. Nono33z

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#2 LabJack Support

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Posted 27 March 2013 - 08:36 AM

If you want to try some troubleshooting yourself, start by using a DMM to measure the resistance from VS to GND with nothing connected to the U6 except for the DMM. It should be 100s of kohms, but on a damaged unit is often just a few ohms. You then remove things 1 at a time until the resistance jumps up to normal. I don't have a schematic in front of me at the moment, but the typical progression is to first remove U16. It is a protection chip and the U6 will operate without it. Then you could one at a time try D19 (near USB), D7 (near AIN2), D8 (next to DB15), and D9 (near yellow LED). Sounds like you might also remove U21. I suggest you continue these details through email with [email protected], rather than here on the forum.

#3 nono33z

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Posted 27 March 2013 - 10:37 AM

If you want to try some troubleshooting yourself, start by using a DMM to measure the resistance from VS to GND with nothing connected to the U6 except for the DMM. It should be 100s of kohms, but on a damaged unit is often just a few ohms. You then remove things 1 at a time until the resistance jumps up to normal.

I don't have a schematic in front of me at the moment, but the typical progression is to first remove U16. It is a protection chip and the U6 will operate without it. Then you could one at a time try D19 (near USB), D7 (near AIN2), D8 (next to DB15), and D9 (near yellow LED). Sounds like you might also remove U21.

I suggest you continue these details through email with [email protected], rather than here on the forum.



Ok, thanks, i will to try this.


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