LFC

NOTE: Sorry about the fuzz between 8min - 11min, didn't catch that after I checked the exported video. I was editing in H.265 for this video and Vegas 14 didn't seem to like it.
A board repair that turned out to be a lot easier than usual.
It's worth noting that while I mention not noticing reverse diode protection in many laptops, I'm sure I've seen Zener diodes across the input on MacBooks int he schematics. This Schottky diode is just a lot more physically obvious on the board than they usually are... I'll have to keep my eye out for them in other devices now, for curiosity.
_
Thanks to music bros down below!
Synthis - / samsynthis
Thomas Hood - / officialthomashmusic

[@yonaemanuel]

Thanks. That diode actually doesn't mostly mean a protection to reversed polarity, but mostly is used to clamp excess voltages when laptop is connected to an adapter of more voltage than its rating. Basically it should be a zener diode of 30V. The diode is always reversed and so if the charger outputs voltage within its safe range it wont conduct anything, but if voltage exceed its rating then it will start conducting, and if the voltage stays for long, it will die with a clamped Short circuit between its pins.

[@assistenzapcromaeur1714]

I discovered your channel and I’m absolutely blasted away for your talent in explaining what you repair, thank you so much , I would appreciate if you could explain more detailed where to inject voltage for short detection without schematics because I have often motherboards where i can’t find the right place where to solder on the positive pole on the correct rail...Thank you m8

[@rafaelmontero5962]

"I never get the simple ones, the easy ones, all the other KZbin channels get the easy ones" Hahaha so true. Genius, Amazing Channel, keep it up, I'm learning a lot from and thanks to you.

[@kannonhouston6754]

You all probably dont give a damn but does anybody know a trick to log back into an Instagram account? I stupidly forgot my password. I would appreciate any tricks you can give me!

[@emmettbo234]

@Kannon Houston Instablaster ;)

[@kannonhouston6754]

@Emmett Bo i really appreciate your reply. I found the site thru google and I'm in the hacking process now. Takes quite some time so I will reply here later when my account password hopefully is recovered.

[@kannonhouston6754]

@Emmett Bo It worked and I now got access to my account again. I'm so happy:D Thank you so much you really help me out!

[@emmettbo234]

@Kannon Houston happy to help :D

[@joshpilla7909]

Sorta new to the hobby and these videos are old but oh well. I appreciate your method of teaching its helped fill in some gaps i was trying to learn

[@jonaskimdl5306]

My new master repair inspiration!! Thanks man

[@theoverkoelen4195]

Had a similar issue with a portable disk once. Also a zener on the internal disk which blew up because the user used the wrong adapter (24V DC in stead of 12V DC). The zener really saved the user from a lot of troubles (all his family photos were on this disk)

[@barrygoodofficial]

I'm happy I found your channel I learned a lot from your video... thank you

[@shooter3267]

Enjoyed your video, really helpful with fault finding.

[@ariansevandal2158]

Wow I've learned a lot, thank you

[@RobCLynch]

Brilliant demo. I started building computers in 1998 and I so wish that I'd specialised in the electronics side - to be able to repair faults on the board. The geek in me draws me to this channel lol.

[@Adamant_IT]

Never too late to learn. I only started learning this stuff in the past few years. Just takes a lot of hours watching repair videos, and some practice boards. Not easy though, I consider myself an amateur at board repair.

[@RobCLynch]

@@Adamant_IT you've inspired me. I've just replaced a motherboard and repaired my son's gaming pc. But with more knowledge, I could've attempted a repair on his actual board. I'll practice on a couple of ancient Pentium 3 boards and study some fault-tracing videos - yours are excellent! Then, once I know what I'm looking for, I'll see if I can repair the board that I have just replaced. I can imagine it to create a huge sense of satisfaction.

[@michaelmayfield4304]

No time like the present. Jump in and get your feet wet. I started doing this in 1978 on anything electronic I could get my hands on. Worked at Xerox for 25 years programming and doing board level repair on 1980's computers until retired and went out on my own. Larger components and no vlsi type chips, but much is similar.

[@ifinstergameplay3210]

i was trying to change the video quality lol. you're good man

[@oddity4650]

Same, I think he maybe needs to do this video again if he gets the same issue then delete this video.

[@UNNIUTHAMAN]

I have also this problem

[@willyrivero470]

Excellent tips. I love your channel, new subscriber here and thumbs up. After watching some of your videos let me give you a trick in return of your favor. When you use the voltage injection method and find the area that gets hot, try to use the lowest ohm scale of your multimeter and use the relative mode and then test across the suspicious components that get hot, usually the culprit is dead short comparing to the others always have some milliohms across it. And just to make sure also do it relative to gnd and +B. The piece at fault usually has the least ohms. That way you lose less time guessing and having that frustrating task of taking off many components.

[@electro3976]

This is good advise, particularly when there are a number of suspicious components connected in parallel.

[@redfrog2100]

Your so good man...explanation..video editing... Thanks alot !

[@MicroMageRepair]

Great walk through.

[@jononeil500]

Thank you for another great video.

[@kuyavhinz7678]

Nice work keep it up!!! More power

[@robinrochan9301]

Hi good morning sir hope you are fine Thank you very much very nice video I learnt so much from you 😀

[@rolandovillanueva6685]

GREATE JOB, YOUR THE MEN

[@cesargarza4560]

i love watching your videos there great

[@Friend_of_the_One-Eyed_Ladies]

"I'll be asking the customer questions."

[@zyxnull]

Oh my!!!! I thought I was the only one never gets the easy ones!!!

[@joshmbehero7046]

Thanks, that was satisfying

[@ariyoso3699]

very crystal clear explanation,,not even my lecturers could do,,lol,,im your subsriber now,,regards from indonesia

[@ACOnetwork]

First, before any repair I would just clean up the fan because it makes me too unsetteling 😂🤣

[@ebrillvaldz8120]

I was like; "Oh, no! Rest in peace speaker cord." I was relieved when he noticed it right away. I have an ACER ASPIRE E15 576g and this kind of laptop is accessible at the back. I was kinda worried at the start when he tried to open the case. That speaker cord position at the bottom is not a good idea, looks like a trap for anyone who is not too experience about this kind of stuff. Anyways, you're an expert you know your way around, so no worries there. But for person like me who has no or little knowledge about this, it's better to do your research and watch the experts do it first before trying to disassemble it.

[@kalich6252]

Was zener diode. In paralel ri power suply it cuts high voltage spikes. Reverse polarity protection would be diode in series.

[@chrisharvie-smith486]

@Terabyte Sorry but nope it's a schotky diode. Failing short saved the rest of the laptop as he said. This laptop has two red two black wires from a commonly used 2.5 mm barel jack. Someone plugged in the wrong power adaptor for something else & that cooked the 1 Amp diode. wrong polarity or too high a voltage or not regulated. The other video has more wires for the LED and the centre data pin as it has an intelligent charger. Different circuit & protection.

[@turnipgaming9747]

@@chrisharvie-smith486 I didn't know you could get Intelligent Laptop Chargers, I'm guessing they detect the maximum voltage and maximum Current the laptop can take while charging or powering the computer.

[@Friend_of_the_One-Eyed_Ladies]

Be serious. It's not a zener diode; you don't shunt-regulate a high power input unless you like smoke! And there's absolutely no reason they would waste a fancy Schottky diode in this application. It's just a plain old vanilla diode, designed to trip the protection circuitry on the charger, and protect the laptop.

[@martijnwijngaards]

Just repaired my Acer E5 575G🥳🥳🥳 It was the same part...

[@dillannelson7359]

I have learn a lot from you, thank you and keep up the good work you're a genius.

[@carlosgarciaoropeza5480]

I was on the lookout. That diode you soldered correctly matches the little diode symbol (indicated in the indelible white ink silkscreen on the PCB). Also, the SS12 part numbers (marking code) of both are identical. Another way of saying it, in its substitution there is no error. On the other hand, repair technicians (Audio/TV) commonly face them in our daily work. It is an original Schottky Diode from ON Semiconductor 20V, 1A and 1.1 Watts. It is NOT a reverse bias diode whose typical representative is the Zener Diode; neither in its symbol nor in its functional operation. They are diametrically different. Both families of diodes are usually tested with a DMM set to the diode test function: a) A display reading of [0.1x ‒ 0.39] in forward bias and infinity in reverse bias is completely normal for most Schottky diodes serviced out of circuit. b) A display reading of [0.6x ‒ 0.7x] in forward bias and infinity in reverse bias is completely normal for most zener diodes serviced out of circuit. Both can also be checked inside the circuit (ie without desoldering) and the readings will be very similar to those given above, but if in doubt remove them and check as in a) and b). Of course we were hunting for a shorted component here but the test method above is applicable as well. I also read your accurate description in the title of this video. Finally, thank you very much for sharing this video with us and our heartfelt congratulations on your successful repair. A sincere and fraternal greeting from Mexico.

[@chillytswak5530]

U the best man...but please show ur multimeter in full.some of us common sense is not always common in us 😁 But thanks man...

[@DennisCrouse]

One of those cheap "universal" chargers. They have just the two pins, and people accidentally put the tip on backwards. I've fixed two of them this month.

[@andrasszabo7386]

Do you always fix laptops with the bottom coming off? I only found one Asus. All my other laptops open from the keyboard side

[@goodelectronics4170]

I like your multimeter bro...

[@damnedattendant2536]

This laptop probably uses those weird chargers/Power supplies used in music system equipment where it looks similar to normal but the connection is reversed ... Probably to prevent user from using 3rd party chargers..

[@BjornV78]

Wasn't that a TVS diode? Those are connected in parallel over the power inputs, to clamp down when a surge or overvoltage occur.

[@veskovesilev2019]

It is for sure.

[@GeordieDonkey]

Would have been nice to know if the customers charger was a cheap knock-off though, good video still

[@johnpuruntong4973]

genius!

[@cephasbanda1531]

❤❤❤

[@AhmedJaviz]

you are my next favourite person.

[@KNFIX-CUCHI]

thank sir

[@prosperngwenya6499]

gadget guru loading

[@chipachipa7601]

Hi do you know under what name i can search that diode i need the replacement

[@pjtutorialsPH]

I have Acer E1-470. It boots from the ac fine. But it does not boot on battery, even if the battery has sufficient charge. If you put the battery while the laptop is on AC (live install), the battery works fine. I can then remove the AC cord and the laptop works on battery fine. The problem lies on the laptop NOT powering up on battery. Also, if the laptop sleeps while on battery mode, the screen wont show anything anymore. It's black. What might be the problem? I tried different batteries, genuine and class a, brand new and not (same battery model) but same problem occurs.

[@amit0356]

I have an acer laptop with charge light but no power on plz help me to solve the problem

[@davidvalens3337]

how did you test that it was not the power jack that was damaged before you took apart the motherboard?

[@techroom6830]

Hi, question, the chip you was poking around at the 11:50 mark, is that a mosfet or an inrush limiter?

[@Adamant_IT]

An Inrush limiter is usually two mosfets in series, so all In rush limiters are mosfets to that extent. But yea, that chip was a mosfet package. It's not common to see an inrush limiter mosfet in that style, but the fact that it's the first active component from the DJ jack is the give-away.

[@andrasszabo7386]

I wonder if you could do magic with my very old Gericom and Texas Instruments laptops though

[@lucaconsales5935]

Hi I have a problem with an Asus n580VD no power laptop could you help me ..?

[@MrOSO-hj6gs]

I replaced a resistor that heats up i mean really hot. After replacement sttill dsnt work. The new one keeps burning hot any suggestions or i duno what to look for anymore

[@Adamant_IT]

Where abouts is this resistor that's heating up? Need to figure out what it's connected to for the next clue.

[@rakhmatarief5903]

how to bypass the batere to power on this laptop ?? i want to power on laptop using ac power only..

[@DARKNESS19906]

Idol new subscriber

[@dick_tm]

And, did the customer bring a generic charger or brought it the original one?

[@Adamant_IT]

It was a proper one. So either this was a random failure, or someone accidentally plugged the wrong cable into the laptop and didn't want to admit it. 🤔

[@ghostsquad4868]

thanks thanks thanks thanks thanks

[@AlCatrraz]

Do you have a video explaining repair of NO CHARGE TO BATTERY ? I have a DELL N14 that works without charging the battery... the voltage on the pins for the battery - computer side - are all at low levels of 1 & 3 volts

[@Adamant_IT]

Not yet, but I have a repair job in the queue with this fault - if I can figure it out, there'll be a video on it.

[@gleceriocalolo5296]

Sir wath a problem about laptop aser core i5 power on but not dest play screen.

[@gleceriocalolo5296]

Me i watch the vedio about repare laptop pls help me about me my laptop problem i show you vedio watch me how to repare about that sir.

[@EsamHandrex]

hallo ...When I put the 20-volt charger into the laptop ... a measurement in the avometer, I found it was 5 volts !! i need help

[@Adamant_IT]

That sounds like a short circuit across the DC jack, likely a similar problem to this video.

[@iqbalreshma925]

Ur videos are nice. Can I know what does a resistance do in a short circuit

[@Friend_of_the_One-Eyed_Ladies]

A short circuit, by definition, is the LACK of electrical resistance where there should be some.

[@iqbalreshma925]

@@Friend_of_the_One-Eyed_Ladies thanks

[@RafalScrapper]

👍😀👍

[@surgingcircuits6955]

In automotive, I hear they often put Zeners in backwards for protection. Maybe laptops, too if they hired an auto guy.

[@Adamant_IT]

Yea I believe it doubles as over-voltage protection, as well as reverse voltage. A 30v zener in there, and it'll conduct if the charger goes way overvoltage for whatever reason.

[@AlCatrraz]

That's what ACER stands for --- Automotive Computer Electronics Repair

[@surgingcircuits6955]

Al Catraz , Ha!

[@Gamefever_10]

Man I’ve got same model and same problem , I suck at checking with multimeter cuz I’m a noob when it comes to these all, but to be precise I’m getting same tone with same part that you replaced, is it a good idea if I replace the same part to turn on my laptop ? Cuz I’ve seen on some site with same model replacing the same part

[@Adamant_IT]

To clarify, do you mean; "Do I need exactly the correct diode to replace the failed one?" Any small rectifier diode rated for about 30v will do, as all this diode needs to do is short out the input in the event of reverse or over voltage coming out of the charger. So it doesn't need to be exact. At a push, you could leave it off the board, although this leaves the laptop unprotected from cheap off-brand chargers.

[@Gamefever_10]

Adamant IT yeah that’s exactly what I meant because on the site they Desolder/replaced same diode and I saw same thing on your video, could it be I’m having same shortage on my laptop’s motherboard ? Do you think it’ll be a good idea to de solder this diode just to check if i can turn on the motherboard and then replace it with 30v diode ?

[@Adamant_IT]

Yea that would work. To check with your multimeter, set it into resistance mode and put the probes on each side of the diode. A healthy laptop should have at least 20K-Ohm over the DC jack. If you're down at 0 or a few hundred ohm, there's still a short circuit. If you remove the diode and the short disappears, you've got your culprit.

[@Gamefever_10]

perfect, much appreciated man, I’ll give it a shot once I’m free and get back to you with the result , you made it very simple for me to understand thanks a lot for your respond and help!

[@RCompHacks]

@@Adamant_IT Did you use SS12 20V 1A Schottky Diode? I can´t find what value is brand Littlefuse 5EJ70 of my Acer E5-522.

[@vlatkosurlan545]

I'm betting on that protective zener at 14:21. Let's see if I'm right.

[@vlatkosurlan545]

HEHEHE! Nailed it!

[@vlatkosurlan545]

Probably didn't even die from reversed polarity. Just a voltage spike that maxed it out. Never assume that people who designed that thing knew what they were doing. Or rather, assume that they knew that a silly little voltage spike will kill that motherboard sooner or later (just in time for a new laptop).

[@stanimir4197]

Finding a shorted input DC - use 0.9V, 5A bench supply and a theremo camera. It takes a minute or so. The latter is godsend for finding shorts (or failed mosfets)

[@yooscripts5947]

where is my friend, the HDD 😁

[@mitechconcepts6538]

Hello, I will like to schedule a training session with you so I wonder if I can get such opportunity

[@Adamant_IT]

We don't offer any kind of training I'm afraid.

[@KrissBartlett]

you forgot to plug that speaker in the first one you took off ?i watched again you did sorry good job i have the same laptop to

[@bobcharles3029]

I think your diode was a transorb

[@Cyberpuppy63]

Nice repair. That fan looked like the family pet dumped a mountain of shedding. No cats, we hope! Arf, arf!

[@rockyvlog4087]

nice got lucky

[@AlCatrraz]

420 degrees... C or F ??

[@Adamant_IT]

C

[@donald1056]

I kind of noticed your not a big believer in flux - you do use it a little bit I see but not all the time - I've never seen a fan clogged up like that - was that spinning

[@misfortune5007]

Shouldn't that diode be a zenner with a reverse bias voltage of lets say a plus 5v volts of what the charger is puting out?! I mean if the charger is puting out 19volt, a zenner with the reverse bias voltage of 24 would probably do just fine.

[@misfortune5007]

@Eric H well a zenner would provide a overvoltage protection as well as cross polarity protection. A diode mounted in reverse bias would also provide surge protection when mosfet open or close efectivly disipating any reverse voltage

[@stanburton6224]

Definitely replace the diode.

[@annyan904]

This again is an easy repair..... With direct dc power supply within minutes you can find the fault.....just have to confirm that the short is before the current sensing resistor or after the current sensing resistor

[@StresSdidri]

Reverse voltage diode dead means somebody used the wrong charger on it

[@wahyung9669]

Tudorache Adrian Yeah those universal chargers with a bag of assorted colored plugs and the nature of those polarity reversable pins. I had to tape mine in case it falls off, in case I forget which way. I always wondered how many laptops they killed on the market.

[@StresSdidri]

@@wahyung9669 At least somebody makes a buck or 2 from the improper "user handling" :)

[@oleezone99]

Thanks a lot i fix my problem :)

[@vasily2022]

A simple fix could have been to remove all those ridiculous stickers.

[@clemstevenson]

Too easy. You want a zener capacitor fault on a power supply. The complex design worked just fine, but a critical capacitor was repeatedly purchased on the cheap. It was only a small non-polarised cap, but the product used was cheap and wasn't rated to tolerate the expected voltage transients. They would eventually go wrong in service. These capacitors tended to go short circuit, but one of the bar stewards only went short circuit at five volts. The meter was reading open circuit.

[@thehitman5007]

Your video is far informative and less boring yappy talk and cursing compared to that rossman

[@SaiyedR]

hey bro your most of the clips of this video got pixellated.

[@davidvalens3337]

if you just shoot with a original BMPCC this would look so much better. you would not have all the pixelation and artifacts in the video

[@daddygamer3978]

Fixxxxxx my motherboard plzzzzzzz

[@ji_raiya1156]

Reverse diodes not very important

[@danielsatko-]

"inrush limiter which is two mosfets"? WTF? hahahahaha

[@HalifaxComputersRepair]

your video is blurry !