Question about output of power adapter - Page 1
Forum section: electronics / beginners

author: rickshaw
author_rank: Newbie
timestamp: July 11, 2017, 11:20:09 pm
content: Hi,Have been reading stuff here but first time to post.I am trying to determine if the problem of my NAS is with the power adapter or the main board of the NAS. So I am tried to determine the output coming out of the power adapter's end. I am getting 6.7V on both pins 1 and 2. The power adapter that is supplying power to the NAS has a 4 pin DIN. I have attached an image of the power adapter's label.My question is. On the label of the power adapter, it said DC OUTPUT: 12.0V. Does that mean that the 2 positive pin of the DIN must read 12V when tested for voltage?Please advise.Thanks a lot!Rick..

author: alm
author_rank: Super Contributor
timestamp: July 12, 2017, 12:23:46 am
content: Pin 1 and 2 should be connected together, and pin 3, 4 and the shell should be connected together. Measuring DCV voltage from any of the positive pins to any of the negative should give approximately 12 VDC. So it seems highly likely that that power supply is broken (e.g. leaking electrolytics).

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 12, 2017, 12:31:59 am
content: Are you plugging it into a UPS? Try with a regular wall outlet too.

author: rickshaw
author_rank: Newbie
timestamp: July 12, 2017, 01:35:09 am
content: Hi,I plug the power cable into a wall power outlet. No UPS. Nothing happens. The light indicator on the power adapter is very faint. Not sure of that is normal since the power adapter is installed inside the NAS case originally.Rick..

author: rickshaw
author_rank: Newbie
timestamp: July 12, 2017, 01:40:19 am
content: Hi,So, the 2 positive pins should give out 12V each. I will look for a replacement power adapter on eBay with similar specs. as what's on the label, with 12V output in pins 1 and 2.I was reading some posting in other forums about a Netgear NAS having a similar power adapter end, a 4 pin DIN. But they were mentioning the 2 positive pins are like 5V and 12V. Any thoughts on that?Thanks again.Rick..Quote from: alm on July 12, 2017, 12:23:46 am

author: alm
author_rank: Super Contributor
timestamp: July 12, 2017, 01:51:13 am
content: That would mean the label is incorrect. Obviously there is no way to tell that without inspecting the supply. If you unplug the power cord, what reading do you get if you measure resistance between pin 1 and 2? If this is a very low value ( < 1 Ohm), then they are likely shorted at the power supply end, and very unlikely to supply a different voltage. My guess, based on the label, is that they just used two pins in parallel for current carrying capacity.

author: rickshaw
author_rank: Newbie
timestamp: July 12, 2017, 02:17:07 am
content: Hi,I did the resistance measure between pin 1 and 2. It was .3.I will go with 12V pins power adapter.Thanks a lot!Rick..Quote from: alm on July 12, 2017, 01:51:13 am

author: rickshaw
author_rank: Newbie
timestamp: July 25, 2017, 01:58:00 pm
content: Hi Alm,I got received a reply from the power adapter seller. He/She said:"both positive pins (1 and 2) on the DIN connector gives 12V parallel connection. Not each."What does that really mean? The 6.7V reading in pin 1 and pin 2 are correct? So sorry, not an electrical person. Just want to determine if the power adapter is defective.Let me know.Thanks.Rick..Quote from: alm on July 12, 2017, 01:51:13 am