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I have a monitor that is no longer working. It had an intermittent problem where it would go "pop", the black out for a little while, then come back on. Then recently it went "POP" a little louder, and hasn't been working since.

I have looked at the PCB to try to identify the broken component. And I found this:

Could it be the top one that is fried? if so, what is it? and Can I change it myself?

EDIT: As someone mentioned, the broken component may not be the one in the picture.

The monitor in question is an AOC U2868PQU. I did look for the service manual, the only one I could find was behind a paywall.

The panel of the monitor is a m280dgj-l30

The controller is a 715G6355-M1A-000-005K, apparently, this controller is also used in a philips monitor.

Rasped
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    Welcome to EE.SE! This appears to be a reverse engineering, modification, or repair question. Please be aware that such questions must involve specific troubleshooting steps and demonstrate a good understanding of the underlying design of the device being discussed, so that you can ask specific, focused questions that can be answered concisely. More information can be found here: [Is asking how to fix a faulty circuit on topic?](http://meta.electronics.stackexchange.com/q/2478/11683). – Dave Tweed Dec 31 '17 at 15:32
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    If you would provide the model of your monitor, then we would be able to look into service manual and probably give some more useful advice. – Anonymous Dec 31 '17 at 17:15
  • Like the answers explain, those are zener diodes. A fuse is usually indicated with F, not ZD. Those letters can be mighty handy in identifying components you don't see often. – Mast Dec 31 '17 at 17:55
  • @Anonymous He should have looked up the service manual himself. If he didn't find it, that's *his* tough luck. – Nick Alexeev Jan 01 '18 at 02:59
  • @NickAlexeev I _did_ look for a service manual. But thanks – Rasped Jan 01 '18 at 16:19

2 Answers2

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From the marking beside it (ZD) and its appearance, it would be a zener diode.

Zener diodes can be used as (simple) voltage regulators.

They can also be used to protect signal lines from over voltage. Given so many of them in a row, I'd expect this to be the usage in your case.

Zener diodes are often color coded. I had a chart that showed values for zeners with a single color band, but I can't find it right now.

This datasheet suggests it may be a Vishay BZV55 zener. In that case, the blue band does not represent the breakdown voltage.

Since you have a bunch with the same color band, you could remove one of the others from the board and measure the breakdown voltage when reverse biased.

Since replacing the broken diode probably won't fix your monitor, I won't go into how you measure the breakdown voltage on a zener.

Your real problem is whatever killed the zener diode. Something caused it to conduct, and pushed enough current through it to cause it to fail. That's the problem you have to find and fix first.

JRE
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They are Zener Diodes in a Metal Electrode Leadless Face (MELF) package (*).

The blue paint indicates the cathode.

It is difficult to identify the characteristics of the diode if it is broken. However as there are four of them, they may well be the same, so you could probably remove and measure one of the other ones to try and find the Zener voltage rating.

Furthermore, very rarely would a Zener diode pop without something else causing the problem. The Zener was likely the weak link in the chain of a larger failure and not the route cause.

(*) I can tell that they are diodes from the package, and that they are Zener diodes from the silk screen reference designator (ZD...).

Tom Carpenter
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    +1 highly unlikely to be the cause of the Pop though. – Trevor_G Dec 31 '17 at 15:05
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    @Trevor agreed. – Tom Carpenter Dec 31 '17 at 15:07
  • Any idea what could be the cause of the "pop"? the monitor has speakers, not sure if it came from them or not. Also, does the top one look broken or is it a normal look eventhough it is different than the others? – Rasped Dec 31 '17 at 15:07
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    @Rasped hard to tell. It certainly looks damaged - there is a bubble in the glass likely caused by overheating. ZD101 also looks to have a slight bubble as well. – Tom Carpenter Dec 31 '17 at 15:09
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    @Rasped hard to tell, they are usually pretty black when they go. It just looks like the paint was scraped off to me. You would have to take it out ant test it to be sure. – Trevor_G Dec 31 '17 at 15:09
  • You are grasping at straws. Glass has a very high melting point, and will crack before it melts. The bubble most likely formed during manufacturing, and is benign. Intermittent faults are usually caused by 'dry' solder joints or bad connections, particularly around parts that run hot (eg. power supply). – Bruce Abbott Jan 01 '18 at 20:45
  • @BruceAbbott Quite possibly. I was just making observations in the comments. The answer itself was to the original question which was "Identify this component" - the question itself has since been mostly rewritten. – Tom Carpenter Jan 01 '18 at 21:23