Laptop does not start, some SMD is blown, what is it?

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Acer Aspire E5-573G

An affordable mid range laptop sold by Acer in mid 2015. This laptop comes with a Nvidia 940m graphics card, Intel i5-5200U CPU, and a 1080p display.

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Paulius @pawliux

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发帖于: 2018年9月1日

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Laptop does not start, some SMD is blown, what is it?

Hej,

I’ve got a laptop Acer aspire e5-573g that is not starting up. Looks like it is not getting any power at all. On one side of a motherboard on the other side of the DC connector there is an SMD blown that I cannot recognize. Check pictures.

Can anyone tell me what is this piece and where can I buy it?

Appreciate your help!

Regards!

!!!UPDATE!!!

I have removed the blown part as shown in the picture her:

Doesn’t the marking underneath the blown piece indicate that it is a kind of a diode?

!!! UPDATE 2 !!!

I have checked the continuity readings from the plus pad and adjacent ends of capacitors. Readings are fine, I mean no continuity on opposite side of capacitor.

I tried to check for splashes or whiskers of solder on the components around without any obvious luck. Check some images:

I believe the latter image shows the PU11 IC and resistors PR127, PR128, PR229 located around it. There no seen defects except one black leg on IC close to the C letter as seen on the following images:

Could this indicate that IC has shorted? Or is it just meaningless debris? The leg looks kind of shorter than the rest as if it was burnt.

UPDATE 3 (and hopefully the last):

Ok.. the SMD part purchased was 1N4148WS-7-F - Switching Diode SOD-323 75 V 300 mA, Diodes Incorporated with the datasheet located her:

https://www.elfadistrelec.dk/Web/Downloa...

The piece is much smaller than original part on the motherboard, picture follows for comparison.

The piece was soldered as shown in the image and the laptop STARTED LIKE A CHARM!

Huge thanks to @oldturkey03 and @pleriche

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Is the schematics taken from e5 573g motherboard schematics? Some other source claims it is transorb / tvs diode for overvoltage protection. Can this be right?

由 Paulius 完成的 2018年9月3日

@oldturkey03 please take a look at the update I made to my question with the newest image. Wouldn't the marking underneath the blown piece indicate that it is a diode? or is it just to help to distinguish between anode and cathode of the capacitor?

由 Paulius 完成的 2018年9月3日

@pawliux ok yes it does. Hold off for a bit. What is on the other side of the board? Let me convert this to a comment so that I am not misleading anyone.

由 oldturkey03 完成的 2018年9月3日

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oldturkey03 @oldturkey03

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@pawliux

according to your image the component is definitely a diode. Attached is the page from your motherboards schematic regarding power/charging. According to the components next to it and the connector being the DC connector this would have to be PD3 which is a 1N4148WS Mouser and Digikey both have plenty of those. Great follow through with the images etc.!

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Sounds great! Since there stands "recommended 200mA at least" I'm looking at this diode:

>>> 1N4148WS-7-F - Switching Diode SOD-323 75 V 300 mA, Diodes Incorporated <<<

with the datasheet found her:

https://www.elfadistrelec.dk/Web/Downloa...

Is it a right choice? Or did I misunderstand something?

由 Paulius 完成的 2018年9月3日

@pawliux that looks absolutely correct.

由 oldturkey03 完成的 2018年9月4日

Super! Will update and accept answer as soon as i get the piece replaced. Of course will check the adapter too.

由 Paulius 完成的 2018年9月4日

I agree with @oldturkey03 that it has to be a diode, in fact my first thought was that it looked more like a diode than a capacitor. But I couldn't see what a diode would be doing there as it appears to be in parallel with those two ceramic capacitors next to it.

According to the schematic it's feeding into the ACDET input of a microcontroller, I suspect an analogue input allowing the microcontroller to measure the input voltage. But there's no reason for that diode to have blown unless there's a short from the bottom end to ground since as connected, it should be presenting a minimal resistance to the flow of current. There's more or less got to be some other underlying fault.

由 Philip Le Riche 完成的 2018年9月4日

First of all, check continuity between the diode pad marked + and the adjacent ends of the ceramic capacitors. You should get continuity. Then check between the other pad and the other ends of those caps. If you get continuity then there's your fault. Examine it with a 5x or 10x magnifying glass or low power microscope. Is there any sign of a whisker of solder, or a burn mark from a whisker of solder that has been vaporised, which would have accounted for the short circuit? Otherwise you'll have to follow the tracks a little further, identifying PR127, PR128, PR228 and the microcontroller PU11 in order to relate the schematic to the circuit board.

由 Philip Le Riche 完成的 2018年9月4日

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Is the schematics taken from e5 573g motherboard schematics? Some other source claims it is transorb / tvs diode for overvoltage protection. Can this be right? — Paulius
@oldturkey03 please take a look at the update I made to my question with the newest image. Wouldn't the marking underneath the blown piece indicate that it is a diode? or is it just to help to distinguish between anode and cathode of the capacitor? — Paulius
@pawliux ok yes it does. Hold off for a bit. What is on the other side of the board? Let me convert this to a comment so that I am not misleading anyone. — oldturkey03
Sounds great! Since there stands "recommended 200mA at least" I'm looking at this diode:

>>> 1N4148WS-7-F - Switching Diode SOD-323 75 V 300 mA, Diodes Incorporated <<<

with the datasheet found her:

https://www.elfadistrelec.dk/Web/Downloa...

Is it a right choice? Or did I misunderstand something? — Paulius
Super! Will update and accept answer as soon as i get the piece replaced. Of course will check the adapter too. — Paulius
I agree with @oldturkey03 that it has to be a diode, in fact my first thought was that it looked more like a diode than a capacitor. But I couldn't see what a diode would be doing there as it appears to be in parallel with those two ceramic capacitors next to it.

According to the schematic it's feeding into the ACDET input of a microcontroller, I suspect an analogue input allowing the microcontroller to measure the input voltage. But there's no reason for that diode to have blown unless there's a short from the bottom end to ground since as connected, it should be presenting a minimal resistance to the flow of current. There's more or less got to be some other underlying fault. — Philip Le Riche
First of all, check continuity between the diode pad marked + and the adjacent ends of the ceramic capacitors. You should get continuity. Then check between the other pad and the other ends of those caps. If you get continuity then there's your fault. Examine it with a 5x or 10x magnifying glass or low power microscope. Is there any sign of a whisker of solder, or a burn mark from a whisker of solder that has been vaporised, which would have accounted for the short circuit? Otherwise you'll have to follow the tracks a little further, identifying PR127, PR128, PR228 and the microcontroller PU11 in order to relate the schematic to the circuit board. — Philip Le Riche

Philip Le Riche @pleriche 声誉积分: 30千 74 27 72 · Answer 1 · 2018-09-02T14:00:33-07:00

Philip Le Riche @pleriche

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I think you first of all need to check the power supply is producing the correct output voltage, which should be marked on it. If not, that might be what has blown this component, or this component blowing might have blown the power supply.

It looks like this component is connected directly across the input power jack. You can use a multimeter to check whether one side is connected directly to the jack centre and the other to the jack outer. (You might find the blown component is a short circuit.)

If so, I’d have thought it should work on battery, if you have a working one.

And on that assumption my guess is that the blown component is a tantalum capacitor, indeed, there are 2 much smaller ceramic capacitors next to it, which would make sense.

And continuing on that assumption, the laptop should work if you simply remove the blown component, though arguably it could be less stable. And if I’m right so far, you could replace it with any surface mount (or for that matter, wired) tantalum with a voltage rating comfortably greater than the power supply voltage, and a capacitance as large as you can get in a similarly sized package. Make sure you mount it with the bar at the same end, or if you use a (much more easily sourced) wired capacitor, with the lead marked + soldered to the pad with a + sign on it.

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Hi,

Can you please show me a picture where the fuse of HP 15 Notebook PC is located in its motherboard? Thanks!

Kaloy

Philippines

由 Charlo Garchitorena 完成的 2020年6月19日

Absolutely right...I removed the blown component on my old Acer and it suddenly fired up again!

由 123456 House 完成的 2021年2月19日

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Acer Aspire E5-573G

Laptop does not start, some SMD is blown, what is it?

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