Toshiba C55 No 3.3/5v rails [Fail] - LFC

[@metrotechguru5863]

Graham, you have the patience of a saint. One of the reasons I never really got into board level repairs is that sometimes, you just can't find the source of the problem, even with really good equipment (although that helps). Sorry that a reasonably priced replacement board is not available to you as that would be the cost effective fix in this case. As others have previously said, It's really enjoyable watching you work even if ultimately there is no good solution to the problem. Cheers mate.

[@j.lietka9406]

Graham, you're to be commended for pouring yourself into this one problem. The extent to which you went to troubleshoot, test, purchase replacement parts, and pulled your hair out is immense! This is one board that won. Great information as far as steps taken, analysis, data sheet info & limitations, testing, and conclusions. Thank you sir!

[@zyxnull]

It amazes me how Adam hasn't any microscope and yet he manages to work with his bare eyes and a lamp mounted camera, this guy is awesome! Also thanks for fail videos, from our side it is so frustrating not knowing

[@DanielsGameVault]

I was expecting the ITE chip to be bad and cause excessive current draw on the 3.3v rail, thus heating up your regulator IC.....but then again, you said you had no short on 3.3v.....strange one, but yeah - I too would eventually throw in the towel since you're wasting more time than it's worth. Great vid as always. Always looking forward to failed repairs since it displays everyday situations a tech might come across, me included.

[@davodamirajam1276]

yes ite or pch chip

[@jinujoseph1353]

I am glad you published this video.. it goes to show that repairs are not an easy street and not everything can be diagnosed. Keep the videos coming. Cheers.

[@dafox0427]

The level of troubleshooting you do is nothing short of heroic. Do you know how many shops would've just told the customer that they need a new logic board and moved on with the replacement?

[@paolomonai9511]

The most probable thing is that trace connected to pin 2 of regulator (feedback if I remember well) is PCB internally shorted. You can prove this easily, testing for continuity pin 2 towards gnd, without the presence of the regulator. If there is continuity, you can try to isolate the pad under pin 2 with a cutter and connect through a wire feedback pin to the divider middle point. Hope this is clear...regards from Italy.

[@STWILDERNESSADVENTURES]

And yet it was one of the most interesting videos in electronic fault detection. Thank you very much!

[@wannabemgtow2540]

I do agree it was one of the most interesting fault-finding videos I have seen as of yet.

[@zachattack9453]

Dude i cannot thank you enough for your channel....you have taught me so much and i cant thank you enough for everything you've done to my life!! Love your channel keep them up my dude luv ya like a brother xD

[@AdamSNook.]

when ever i come across a blown chip i simply just search the internet and look at close up of the motherboards image to get the numbers

[@silas184]

Keep the videos coming, even from the fails we learn! Admire your patience and for posting your fails as well!

[@michaelleeper3649]

Thank you from across the pond. I am learning an incredible amount watching your videos and much of it has been applied.

[@azuararuiz]

Put in your place, I would have arrived after reflecting; because I need a thermal camera (I see you already have one that you connect to the phone) and then also a support base for PCBs that I saw in panavise ... it's easy to say in hindsight but the decision would have been made right here, another way of To say it, this kind of motherboard problems has exhausted my patience. Thank you very much for sharing Graham and I mean that with absolute sincerity. All the best.

[@CXensation]

I remember from my my first commercial job after the airforce - back around '81 - we had a "Tone-ohm" in the workshop, to trace shortcircuited pcb tracks. Its a simple 4 wire milli-ohm tester with both a display and a beeper with a varying pitch according to the actual measured resistance. It had of course a range setting switch afair it had 4 selectable (milli) ohm ranges. It was easy to use and you quickly traced down a shortcircuited spot on a pcb.

[@maxwarfield6699]

Where on the pcb, would you know to connect the wires? Asking ‘cause I’m a noob but I want to learn. Thanks

[@CXensation]

@@maxwarfield6699 To use a Tone-ohm you must already know 2 points from where you measure a shortcircuit. For instance on a 12Vpin to Gnd on a supply connector. Then you move one probe along one PCB track to find the lowest ohmic spot (lowest pitch tone). Repeat with the other probe and ypu will be guided to the shortcircuit.

[@peterr2277]

what a lucky find, i am a bit of an electronics hobbyist, your presentation is 10 /10, the image as clear and easy to follow, the verbal description of whats actually going on is very good. i book mark this page

[@felixlersha]

The customer should be more than satisfied with your efforts, especially after seeing the vid. Sometimes the device is just a lost cause even if you are an electronics repair genius with top notch diagnostic equipment and repair tools. If your labour rates weren't as darn reasonable as they are it probably wouldn't be even worth investigating, other than at a superficial level to ensure there isn't a quick and easy fix. Of course it still makes excellent material for a LFC video so thanks for sharing!

[@jscancella]

Glenn Morgan yeah seriously, where I live the rates are so high you could have bought a whole new pc for the cost of the investigation he is doing!

[@dilbyjones]

John Scancella obviously but sometimes that’s not the point

[@BikeLifePinas]

Posting failures are rare these days. I appreciate this video upload as you are able to test your limits. hope there is a part 2. Watching this in Jun 2021

[@RumbleRepairs]

Really enjoying your repair series. I actually repair guitar amplifiers. Many of which have partial SMD layouts as well as the discrete stuff and ICs. Very clear and helpful methods. Please keep up the good work. All the best from Sligo, Ireland

[@abduyusuf7729]

hat off to you graham. am laptop chiplevel repair student from ethiopia. i learn a lot from you. no one teach us in such depth. thanks keep posting up

[@riccardoz2953]

then u should talk with other students and talk with the director, and send home the teachers. if u are a student of a chiplevel repair school and dont teach this... what are they teaching?

[@AndroidPCMMORAW]

This is like finding a serial killer detective stuff style.

[@морс-ф3д]

))))))))))))))))))))))))

[@geoffreykeane4072]

Hi Graham, the schematic you are using seems to date to 2007 (see 20:49 of the video). That predates even USB 3, so there must be a later schematic for the C55.

[@RWL2012]

I also saw "CPU Merom", which is a Core 2 Duo.

[@stevec2196]

I wonder where he got the schematic?

[@safn1949]

Take laptop,add dynamite....fixed. Seriously,that thing is haunted. When I lived in the US ,getting a replacement MB was so easy I never got into board repair,that and my vision sucks. Great video,my friend.

[@jimmy91710]

Please keep the FAILS coming, I think I like them more than the successes...Cheers.

[@williamdawson6351]

possible shorted inter-layer trace can be hard to find

[@Mustafay3sil]

Inject voltage => sprat ipa => turn on a powerful light across the board and find the heating area. ı could find the smallest size shorted cap with this method. (Of course ı got crazy before doing this :) )

[@rougeleroux6803]

Even if you did'nt manage to fix it,still its entertaining to watch at the least and there's so much to learn

[@lordbobrules]

Great channel. The boards for that model are under $40 all day long on ebay. I usually just replace them.

[@trumanhw]

But the edu is far more valuable than the $40 either way. I'll be signing up (donating) to this channel

[@necro_ware]

Very nice though, sometimes it just doesn't want to be found. And thank you for sharing this, it is nice to know, that it's not only me, who fails sometimes :D Anyway, keep up doing great job!

[@brianduncan5758]

Thank you for showing the torture, thank you for great technique

[@JmC023]

JP8102 looks melted into the PCB and dark on the edges at 10:12, I see under your tweezers, mentioned earlier where there was suppose to be "something" there but wasn't according to the schematic. Possibly remove the grounds on both USB Ports and not have USB (Isolation) may have (or may not if it's along the 5V Rail) been able to Power On. Great detective work sleuthing around by the way!

[@TheSauronchik]

1. USB short circuit is bad because it might lead to death of CPU or chipset. This? 2. Short circuit between layers under that regulator? 3. Some tiny capacitor or resistor somewhere on this line? 4. Gremlins? Good video! I'm waiting for a video about ALL of your tools. Especially poor man's microscope :) And you NEED a decent infrared camera.

[@CM-xr9oq]

nah, IPA or freeze spray will do just fine. Rosin pens are another option..

[@ricardocosta3991]

You cannot win them all mate... Enjoyed watching this one just as much as the other videos...keep up the good work.

[@PapaMav]

Watching listening to your Stream this past Saturday, I could not understand why the volume was so low on my C55-A (had the same problem last Mike's Unboxing Stream I was watching). Figured out the right speaker on the laptop has stopped working. Looking into cost of new speakers to see if worth the trouble of taking the bottom off.

[@ebalcarcel]

Love all your videos and the way you explain things. You really give us a very clear way of how things work. I jus wonder why flux is not use when soldering and desoldering devices. Keep up your great work. I am learning a lot from you. Thank you very much for your time explaining thing!

[@jamesvozar1]

Hope you get too read this mate, you have the best tech channel on youtube and deserve many many more subs. have being binging your videos for a week now. cheers james

[@pascalmathieu9332]

Hi, thanks for the video. When you put alcohol, the two transistors at the top left also seem to warm up

[@bulwinkle]

You would expect transistors to warm up as about 0.6v is dropped at the junction so they have an internal resistance.

[@dilbyjones]

These videos are really well explained

[@josephking6515]

Regarding the hot air temp, a channel I watch, Paul Daniels (no, *not* the magician) uses an 8mm nozzle, 450°C at 110 litres/per minute. Your channel is very interesting. Thank you for posting the videos. 👍

[@silentium3171]

I'm not a elecronist yet, but if the 2A usb chip shorted out, for 1x usb2 1xusb3, wouldn't have made more sense that you repairing it should pick up a 2.5 amp just so it accomodates the user that fried it ? Or you think the smps was rated at a maximum and as such only 2 amps can be drawn from that dual port ?

[@maxwarfield6699]

How many of us, can truly say: “I am an elecronists!” Really?

[@saintsaul2502]

Its really tough to fix it You are great engineers and teaching it to all of the world , techniq connect to money and becoming rich but you want to teach your skill without fee, its great but sometimes you Should have to be commercial, its so hard to live without funds, thank you always for your Great lecture.

[@baghdadiabdellatif1581]

Hi Graham. Dont give up maybe use a jumper wire and eleminat the inter line trace that caused the short

[@SSchaeneman]

I love watching your video's , they help me a lot, thank you

[@d3f4ultpl4y4s]

Back in the day I had similar problem. Drove me crazy. In my case I removed USB port itself and problem was gone. I assume there was something inside that port shorting stuff. In your case, its probably anyone guess.

[@deelkar]

in the schematic the 1.8V Sense line from pin2 goes to a GMT_G2997F6U_MSOP10_10P chip, that itself controls voltages depending on power states, but it goes to a whole ton of other places. I don't think it's a sense line, more of a control line, because Pin2 seems to be T_ON

[@tanerriffat7963]

Fantastic! They just keep getting better. I leaned heaps on this video. Thanks Adamant IT.

[@babydust2me205]

Keep on vlogging, I always watching your videos, and I learned from you little by little

[@hadireg]

👍👍 great investigation Graham! lots of teaching. If I was rich I would have sent you a flir camera! thanks for your sharing

[@GlishaSo]

One question for you @AdamantIT can you please tell us or show us which "poor man camera microscope" you use ? :) screen looks amazing but looks like you don't have some crazy big microscope camera for that. Thanks a lot if you answer me! Big fan !

[@GlishaSo]

thanks for no answer :D

[@TheOneTonHammer]

Depending on the revision, the C55 motherboard is only $8.00 on eBay. Just replace it and add the old motherboard to your wall :)

[@greenzero3389]

That's exactly what I would have done. It's commendable the efforts Graham went to, to try and repair the board. Interesting video aside, time wise it would make more sense to replace.

[@wthornton7346]

Cheapest I saw on ebay was £34. Most were in the £50-£60 range. Rip-off Britain?!

[@greenzero3389]

@@wthornton7346 That isn't cheap !!! but not too bad if your labour is around £40/50 making the repair bill about £84

[@TheOneTonHammer]

@@wthornton7346 Toshiba Satellite C55D Laptop Motherboard AMD A6-5200 2.0GHz 6050A2556901-MB-A02 Condition:Open box Bulk savings: Buy 1 $8.00/ea

[@wthornton7346]

@@TheOneTonHammer I don't doubt it but I would have to pay mail and import charges! Lucky you, unlucky me!

[@jamesvozar1]

@Graham, would be funny if you made a service sticker that said, "its fine now!" haha thanks for all the great vids from Australia.

[@ionutnedelea780]

Hi Graham can you tell as please where do you find the schematics for mother's thanks 🙏

[@micflynn1]

could the short be coming back thur the 5V rail and into the voltage divider.

[@WayWorthRacing]

Would a thermal image camera be able to help in these situations to find heat where there shouldn’t be or because everything is so tiny it would just look like one big heated mess lol, Just a thought ,FYI im a wood worker not an electrical engineer, just throwing my 2 cents in.

[@Adamant_IT]

Depends, very small shorts don't heat up enough. But I do need a thermal cam for general shorts, and plus you never know what it might reveal about rabbit hole issues like this.

[@fredwooding6662]

Please tell where you get your Schematics from ?? I am in the US and ZXW is no good for laptops.

[@Adamant_IT]

Literally google search "boardnumber schematic" and there'll usually be a link to one of the many repair forums such as Bad Caps. You'll need to register a free account with most of these places to download attachments, but you shouldn't need to pay.

[@Simon-ui6db]

Good shout out for Louis. Think it was watching his site yours turned up as a suggestion.

[@reggiedixon2]

Enjoyable video, I agree with the idea that you probably learn more from stuff that doesn't go to plan.

[@sydmichel]

low Impedance across the DC jack? Freudian slip perhaps?

[@fredwooding6662]

Thank you So much for returning an answer to my question. Have a Great Easter 🙂

[@zx8401ztv]

Don't feel too bad graham, we all get dead end faults and it's not because you think you are not good enough to find the problem. Yep i have also fell for the wrongly named continuity mode :-(

[@colinreece3452]

I'm way way late watching this and forgive my ignorance sd well, but when you placed the chip on the board it spun, does that make a difference?

[@FriendlyDigger]

Okay Okay, you've done your best and it doesn't work out, but then it's time to just put the thing aside. man that patience you have with this kind of work Yes of course you need that but still respect for your persistence

[@UrosAndric]

You had it there. Just had to use thinner wires and trace it. Go for 2V and pump up the current as much as your power supply will give it to you but start with 1 amp and see how much and where the heat is. Then crank up the current if there is no noticeable heat. I had similar situation with one laptop which have dropped. I had interlayer connection on one spot. it was like weird resistance of 22ohms. My idea was to let the current thrue that part and see if the current will fall or will go up. Idea was to put enough current to burn that connection but not to high to weld tho layers together. I started with 1 amp and after a few minutes it fell to 0.9amp. then i pumped it back to 1 and so on. after halph an hour i was able to put enogh current there so burn that connection. the ressistance vent up to kiloohms and after i puged it up the voltage was restored to 12V. Unfortunataly i had one more circuit dead on that laptop so it is still not fixed, but i was able to sortthat short.

[@jojitnartates2469]

very informative. just upload fail or fix video. your one of my favorite tech.

[@manISnoGOD]

hi can i test mosfets on a motherboard with a multimeter or do i need to remove the mosfets its the 3 leg mosfets

[@gregoriomandigma3817]

I wonder if you pull up super io chips, may be the shorted will vanish. May be the supply of super io chips is around 3v or 5v. Please let me know how many volts it is.

[@ikativan2110]

Persistence is your middle name Graham. 😉😉 Thx for the detailed video!!! 👍👍

[@rafaelulloa320]

Changing de voltage regulator worked for me, but it was too good to be true. I was formatting the hard drive and after one hour, it suddenly shut down, no led indicators, totally dead. When I inspected the mobo again, it didn't have any short circuit but I could hear a very soft ticking sound that I could not know where it came from, checked electrolytic capacitors and they where ok. Any idea what to check?

[@MohamedElSayed-ql4ue]

I think the short may be in the other USB section in the top of the MB and the jumper connection is made to have a overall the 3 or 4 USB feedback lines so it's actively regulated sorry for bad grammar

[@tomaszpluta5839]

Great, very informative video! You can learn a lot from failed repairs. Thanks, cheers!

[@killer6172]

This is the very sad episode that I watch from you Adam..

[@donald1056]

I might be looking into the IC chip ???????????

[@martinvaughan5953]

It seemed you had a lot of solder on the centre pad of the regulator

[@andrasszabo7386]

At 18:31 there is a big electrolythic capacitor(aluminium) on the middle of the screen. And on its left side there is a big solder blob that should not be there if I am correct. Or at least that does not look good.

[@hardkore360]

it's there on purpose, JP8100 is similar to JP8101 just further down on the motherboard

[@inframe31studiosphotocinem52]

Time to donate somethings to this guy, he's actually run out of a time working just with that multimeter

[@RuiRex]

31:17 How do you get away with that much solder on the center ground pad??? and then pressing on the chip... I think it's a miracle you don't short every pin to ground there...

[@bulwinkle]

It squeezes out and onto the other solder pads which is why you need to clean them up with the iron. The board has a solder resistant coating so solder tends not to bridge between pass.

[@Opapa-Jan]

Hi Graham, I usually see in the examples that the output at the second mosfet is 0 volts. But now I have a laptop that doesn't work anymore. On the second mosfet it gives 28 volts on the output. Input is 19 volts. Is this normal. I don't quite understand how to detect a faulty mosfet. If it gives 0 volts then I know that it is broken, but now with a higher voltage on the output I do not understand it anymore. Can you show some various advantages how you detect this! I love to see your videos. Keep it up.

[@Adamant_IT]

I'm not an expert with mosfets yet, generally the only failure modes I've seen is fail-short - so it's just shorted from input to output, or to ground. To be sure about a fail, you need to remove the mostet and measure it out of circuit really. I'm told that you should get about 10k from in to out.

[@Repair5700]

Adamant IT Okay, I'm going to test it. Thank you

[@AbbasAbbas-wt3bo]

brother which microscope u r using

[@Adamant_IT]

Logitech BRIO webcam

[@xx3868]

any followup to this video?

[@lesleymunro4964]

you should look for pad 19 and pad 20 on the schematic, that could let you isolate and test the regulator output with no load on it. I think you need to trace the +V5A rail and see what it is feeding. Also, I did notice one of the small orange caps around the regulator you replaced looked cracked. Just left of the USB 0 ohm link. it looks two tone coloured. might be cracked/failed. worth checking. You did awesome troubleshooting steps though.

[@clems6989]

Well that was a fun ride to work, thanks.. Do a part 2 and Fix it . Come on man don't quit now.

[@QsTechService1]

It sucks getting trolled by PC boards did you give it another go ..

[@catriona_drummond]

Ohhh another rabbit hole, those are the best! *fetches popcorn*

[@alessandrozax]

I'm waiting for the 2nd part of this clip to see the solution..regards from Italy. 👋

[@DavidLeeMenefee]

Try blowing the short open with higher current perhaps?

[@marcelsimon6425]

To raise the current you need higher voltage. If there ist any con to the CPU you could blow that up. The other smd parts may also don't like it.

[@wirenutt57]

@@marcelsimon6425 Well, he can solve the cpu issue by popping it out. Like he said in the beginning, it's a socketed cpu.

[@santiagobarrera2387]

What do you think of reballing and how would you determine that a BGA chip has some pins unsoldered?

[@Adamant_IT]

I haven't gotten into reballing yet... it's generally not an issue I've encountered enough times to be worth learning yet. Most likely times you'll see it are soldered RAM (which you may be able to reflow) or a GPU. If it's the latter, you're going to need specialist equipment to deal with it, and even then good luck finding good replacement chips =/ It can definitely be done, as many people on KZbin have proven, just outside my scope at the moment.

[@santiagobarrera2387]

@@Adamant_ITThank you a lot for your response! I really enjoy your videos! please keep going!

[@Snowbag1998]

That was a tough one. Great troubleshooting steps though !

[@mevlutunlu42]

Hi Graham sir. I am new at this kind of repairing thing. I am a learner actually. I want to buy a new auto range true rms multimeter. are you happy with the vici vx99? It is a little bit expensive though. Do you think Uni-t 139c will be ok as it is a little bit cheaper than vici?

[@Adamant_IT]

Yea for low end multimeters, there's very little in it performance-wise, so go with what you can afford. The Vici isn't exactly prestigious. Look for the UEETEK AN8008 as well, EEVBlog found it to be a hidden gem in budget meters. I've had it on my Amazon wishlist for months.

[@mevlutunlu42]

Adamant IT thanks.

[@petboule2010]

i watched only two videos from your channel i already learned Enough even though you failed this one

[@DavidLeeMenefee]

Can you tell me the name of the program that you are using to open the schematics, I am unfamiliar with that one thanks in advance.

[@Adamant_IT]

Schematics are usually PDF files, so any PDF reader of your choice. I'm just using Adobe DC.

[@DavidLeeMenefee]

@@Adamant_IT I have Foxit so I'll try that thanks.

[@garyg3916]

instead of thinner solder , why not thinner solder tip .. ?

[@concinnity1240]

@31:15 Btw, when you installed that controller chip, it spun 90° from how you originally installed it!

[@hardkore360]

noticed this as well!

[@Luke-12V]

Hi,part 2 ? Pls 🤔🤔

[@carlosandres8974]

i have a question about a graphics card i broke not to long ago i had a medal dropped on my graphics card while the computer was on and it felt behind the memory chips the card turns on but no video output could there be a way to fix that or if i want it repaired how much would it cost me. the card is a 1080 ti turbo

[@anks888]

After you have cleaned the solder from the sides you should reflow it again with flux to eliminate any bridges from the center pad. More than likely that's your short to ground on the feedback

[@funnyvoiceSWHK]

i was thinking the same thing

[@Adamant_IT]

I had considered that, but when I removed the solder jumper on the back of the board, the short was removed from the feedback line, and continued on the separate net that wasn't on the schematic.

[@robertcaldwell7737]

@icedrinker8 multiple pads need reflow

[@gumo77]

@@Adamant_IT I'm curious if this method could work to find the short: www.analog.com/en/technical-articles/locating-shorts-on-power-planes-of-multi-layer-pcbs.html

[@alexeypiterskiy8139]

@@Adamant_IT Did you try to solder out the mosfet Q75 ( low side) and Q73 (high side) on your schematic. The shortage on 5V line could lead those mosfets to be burned/ And also pls measure the resistance of data line USB to gnd. Should be the same numbers for Data+ and Data-. Seek Thermal and Flir are great tools to find shortage in BGA chips and power mosfets

[@ndumisodube76]

keep them coming very educational l love all your motherboard repair videos best videos

[@ndumisodube76]

sometimes l wish you post evryday

[@ajaykumartargotra2768]

For that 3v near battery connector, I guess battery it's self has inbuilt circuit in concealed battery case, for senses. If I am wrong please correct me. Support from Australia .thanks

[@jesusyuca1483]

I wonder if he ever got it fixed. I would have checked under whatever got burnt. I think the short is in the board. Btw I didn’t see a single bit of the video only heard it.

[@HalifaxComputersRepair]

hey what type of microscope you use?

[@Adamant_IT]

Not a scope, but my bench cam is a Logitech BRIO webcam.

[@stevanderpeer]

I see that the USB chip that you removed was a Q11G-G??E1 not F1 time stamp 13.08.?

[@Adamant_IT]

Yup, I did spot that before ordering - there's a correction at 27:08 for this. Sadly it didn't matter as I didn't get as far as fitting the new USB power chip, but ye.

[@stevanderpeer]

@@Adamant_IT I am a complete beginner at this and I am learning from watching youtubers. as you may now I am the one with the GTX 1070 problem (still not fixed) powers up to Bios but black screen when on windows boot up tryed install of drivers and get version of windows not supported and no gpu found even though the gpu fans are spinning. quick q what courses did you take? I am thinking of learning a bit more by taking some collage or uni courses I work as a Chef at the moment and this is just a hobby. I work for a Uni so may get courses cheaper lol

[@Adamant_IT]

I'm not aware of any formal training for this kind of work, other than small companies like iPad Rehab who do phone repair courses. Most people in this field are self-taught, or are electronics engineers who have crossed over from engineering into repair work. I did a basic computer course in college, but 99% of my knowledge is self-taught purely from projects at home, and just doing this as a job. When I started my shop 10 years ago, the idea of actually fixing a motherboard was an alien concept to me - I had no idea it could even be done. You build up to this stuff as you go.

[@stevanderpeer]

@@Adamant_IT Thank you

[@fyremoon]

What I'd suggest is to test the voltage coming to that regulator, it looks like the bigger regulator is discoloured (top left) and if it is shorted and dumping 19v to the smaller regulator instead of reducing it to 5v, it could explain why the regulator is burning up.

[@Davysguru]

It's either the cpu or io chip...problem.....