WD My Book Duo NAS WD10000D033 - No Power

[MLBZ521]

WD My Book Duo (Blue Rings)
Model Number: WD10000D033

Long story short, I accidentally plugged in the wrong power adapter to this NAS device. It started to have a burn smell, so I took it apart and found a burnt chip. Replaced the burnt chip, but still the device will not power up. The chip is a APM4532.

Now when I plug in power, I get a quick power light flash and then it goes out. I'm attempting to power it up without any drives attached. I have a second one of these, exact model, to reference. Using the proper, original Power Adapter now as well.

Would anyone have any recommendations on where to begin further troubleshooting? I appreciate any assistance anyone can offer.

Pictures attached of the board. If a different angle or a closer picture would help, just let me know.

Thanks!

[jondoe]

Re: WD My Book Duo NAS WD10000D033 - No Power

If you have an identical board I'd start by comparing components, with the power off, around the power jack input area, check the diodes (D) and transistors (Q). Hopefully you've sacrificed something around that area.

[stj]

Re: WD My Book Duo NAS WD10000D033 - No Power

check your soldering around the chip you changed.
i wont give it away, but there is something obvious in the picture.

[MLBZ521]

Re: WD My Book Duo NAS WD10000D033 - No Power

@jondoe
I'll check the components to the best of my ability this evening.
I have a working, identical board/unit -- but I don't want to sacrifice it, just use it for cross checking.

@stj
I'm going to say that this is like programming and that I'm staring at the problem, but don't see the missing ';' or something similar. Heh

Are you referring to the chip itself? Between two of the legs? I looked at the board physically and there is some solder hanging out _under_ the chip between the two legs. I don't know how that is showing up in the picture. I'll clean it up this evening and see what I get.

I appreciate both of you taking the time to respond.

[stj]

Re: WD My Book Duo NAS WD10000D033 - No Power

c107 has a wisker on the right, i suspect you caught it while doing the chip.

[MLBZ521]

Re: WD My Book Duo NAS WD10000D033 - No Power

Ok, so....looked at this a bit more this evening and slightly confused, but do have good news.

So, I started cleaning up the components around where I replaced the chip and then tested all the diodes and transistors I could find on both sides of the board. Everything seemed pretty 'even' (to my level of knowledge) and I compared them to my second NAS's board and everything was still pretty close in readings.

Decided to compare the 'power on' characteristics between the two and found that they both exhibited the same symptoms...but this other unit worked previously?

So I grabbed another power adapter for another WD Unit (albeit for an external USB single HDD unit), and it worked just fine to power both NAS's with HDDs attached. So now I'm confused why the original, proper adapter does not work. I do get 12V from my DMM. I literally used the original power adapter to reset and wipe the 'working' unit a couple months ago.

Oh well, buying a new power adapter is better news than the board having lower level problems I guess.

Again, I thank you guys for your time!

[stj]

Re: WD My Book Duo NAS WD10000D033 - No Power

if your meter see's 12v it does not mean it's smooth.
try with the meter set to AC to see the ripple.

you need to open the psu and check the caps.

[CapLeaker]

Re: WD My Book Duo NAS WD10000D033 - No Power

yeah... bad PSU. Recap the old PSU or swap it out.

[dragos2009]

Re: WD My Book Duo NAS WD10000D033 - No Power

diode d5 looks burned

[MLBZ521]

Re: WD My Book Duo NAS WD10000D033 - No Power

@stj
Ok, so I tested the original PSU on AC and when I apply the red lead it rapidly drains down to 2.0mV and from there is slows down, but continues to drop to <1.5 albeit slowly.

I ordered another PSU last week and it came in today. Both hold the same DC voltage, but the new one does hold in the 25X.XmA range.

However, the new PSU also will not power up either unit I have.

This is the proper adapter I'm almost positive (the specs match at least): https://support.wdc.com/knowledgebas...r.aspx?ID=1378
My Book World Edition II (Blue Rings)
12 Volts / 4.0 Amps / 48 Watts

But both units work fine on the smaller Ktec adapter that goes to a External USB drive...?

At this point, I think I'm going to get another Ktec Adapter and use it.


@dragos2009
The D5 Diode is not shorted, I did test it and the unit does work with this smaller PSU.