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.

[@killer6172]

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

[@wallysemenoff8110]

send it to sorrin hes the man to fix stuff like that

[@Mustafay3sil]

Yeah The All-Board-Man :) Master SORRIN

[@deexboy]

“Some day we may replace the capacitor...”

[@boolfnasa2582]

Adam did all what Soirin could have done and maybe more, the only difference is that Sorin wouldn't have posted the video, neverthless Sorin is also a master in repairs, but ADAM is one too.

[@19mati67]

I had the same issue with an Asus Q502LA and I could not figure it out. I have got another board, and now my HDD sometimes working and sometimes is not recognized. Very frustrated with this laptop.

[@paulmuff9883]

Thanks 😊

[@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?

[@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

[@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

[@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

[@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

[@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.

[@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..

[@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?

[@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.

[@michaelleeper3649]

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

[@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.

[@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 :) )

[@trumanhw]

Could the laptop have started when you isolated (by removing) the "solder blob bridge" near JP8109 ..? ( @45:00 ) ..? (I'm here because I know nothing) ... While I'd definitely like to know how [you] learned what you know and importantly, what that process consisted of! ... such as: Did you start off breaking things at 6 & tried soldering at 8..? Or did you get sidetracked from EE major? Or however you learned practical application -- as well as the principles (physics fundamentals) and, how deep your academic knowledge is. Can you explain from both a Maxwell's Laws as and then show how and why switching over to ThermoDynamics (conservation, etc) ..? Or is Ohm's law & hands on (kinesthetic) adequate..? Whether that's too personal or just not your 'cup of tea' ... I'd really get a lot out of videos drilling down on YOUR approach to: - The "normal" vs abnormal SMD component behavior (pathology). - How do you follow AC path, as traces LACK "observable continuity" ...? -- Does this require accurate expectations to be confirmation with a multimeter (DMM)..? - Given frequent relevance & apparent importance of "short to ground" & "shorts" or "ground" generally warrants a DEDICATED video! -- The meaning? When / where it's expected? How's it identified? And, "rote" repetition with a series of boards (practice.)!! - PLEASE dedicate a vid to the significance of continuity, impedance, or other DMM modes. - Many small components look identical; how do you tell them apart? Color? Memorization? Or just testing (DMM)? - Do you have "crutch" concepts for inductors, caps, diodes, filters, etc., that better abet _intuition_ than _tech definitions_ do? PLEASE do a video *Discussing How You Developed Schematic-Literacy!* I'd assume you'd need a relatively fluent understanding of the component on a schematics before reading one makes 'sense' ..? As reading comprehension depends on a vocabulary & concepts of nouns, verbs, adjectives etc are to understand sentences... While a vocabulary of words abets sentence comprehension, inference skills of a paragraph or page is another (higher) level. Understanding a circuit within a schematic "a phrase in this metaphor" wouldn't provide macro level concept of how it works together. YOUR VIDEO'S STYLE OF ... _hands on, practical application simultaneou to asides with technical explanations are utterly UNIQUE! And more importantly, WITHOUT PARALLELE ... and exactly what I was LOOKING FOR! Dedicating videos to each of the above topics would be, if not the only instance on youtube..? IMO, by far, they'd still be the best. This is by far the most useful and valuable channel on this topic I've ever found.

[@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.

[@silas184]

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

[@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!

[@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.

[@AndroidPCMMORAW]

This is like finding a serial killer detective stuff style.

[@морс-ф3д]

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

[@stevec2196]

Toshibas are rubbish! I have a Satellite A665 that turns on for a few seconds then shuts off. Want to work on that one?

[@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

[@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

[@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.

[@frankg2167]

to much solder in the middle of the pad. maybe the to much solder short the pins of the ic

[@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!

[@brianduncan5758]

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

[@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?

[@ElectroBotVideo]

Its really annoying that "engineers" took TWENTY years (1995-2015) until they standardized a USB connector that wasn't stupid. Yes, I'm aware that a dual sided connector is more expensive due to contacts at both ends, but they could have designed a connector like HDMI/DVI/VGA/etc. where its easily discernable which way it goes.

[@rajdev555]

hats off to your patience and dedication sir. advice: check boardview (.brd)file that will be helpful.

[@KBFix]

I have wasted many hours on these kinds of faults..... last Resort inject voltage until she cant take no more! *pop*

[@Davysguru]

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

[@AndroidPCMMORAW]

Power on, nothing happen ? the BEST FIX - hit it with a hammer 100% working.

[@BigEightiesNewWave]

Fist-bump worked in the black&white TV days.

[@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.

[@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!

[@johndoe4880]

i would have looked for the motherboard on ebay and gave him a new motherboard instead of going threw all this. for me its would be easier to do that. wouldn't it be easier

[@concinnity1240]

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

[@hardkore360]

noticed this as well!

[@sydmichel]

low Impedance across the DC jack? Freudian slip perhaps?

[@rodeljavier9179]

try to change super IO chip..

[@DavidLeeMenefee]

VCC = Voltage Common Collector...fyi... see 21:20 or there abouts

[@starfirezz]

This boardview seems to be a close match for the motherboard in question: www.alisaler.com/pt10s-uma-mb-rev2-1-boardview/

[@Scalee]

This really does seem to be the exact model.

[@hadireg]

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

[@the_socompsp]

get a cheap (like $100) logic analyzer. this will help solve possible bus issues coming from southbridge or firmware chips/cpu data. you have a short to ground on that rail, you need to remove all caps and resistors that are connected to said line and check them.. you cannot properly measure them while they are IN the circuit you have to remove them first. could also try removing and measuring the larger can caps too.

[@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.

[@devonoved7]

Have two dead Toshiba satellite C50 notebooks as proof that the company just wanted to get out of making laptops.

[@final0after0image]

Yeah they weren't great pretty sure I had a similar fault on one of these. No idea why anyone would want this fixed though its not like this kind of work is cheap but the laptop its self is.

[@hazemreda3504]

Hope this helps : 1- The schematic you are using is not the same as the board you are working on and noticed that the regulator IC is 24 pins on the schematic but on the motherboard is only 20 pins, so you could use it as a reference only to understand the circuit because i also didn't find schematic for this board but i have found Boardview in this link www.alisaler.com/pt10s-uma-mb-rev2-1-boardview/ 2- I think you have nothing to do with the 5V_FB line because it is getting short after U8100 5&3V regulator IC burn and become faulty or the pins 2&3 shorted accidentally when you soldered the new IC 3- Your main short start from pin No 3 of the IC U8100 which is RTC_power as referred on the boardview and it is connected to JP8109 which it's +3VA line that you have already isolated it in the video, so you have to look for short start from the other side of JP8109 and it's going to different places, one of them is the Super IO chip 4- For the R8101 in minutes 46:36 it's correct, nothing wrong with it, one side connected to ground and the other is connected to the U8100 5&3V regulator IC

[@ashleyharflett4238]

Resistor normally never go short circuit only open circuit, capacitor go short circuit Must be something after the ic you replaced , ie a short in the USB sockets. Maybe worng

[@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.

[@crazycraigy01]

My C55, Core i3 outlasted my New Toshiba L50 which lasted 18 months, My C55. is on 24/7...bought Refurbished for £220 from Argos Ebay Site in 2015...plastic keyboard but Solid.

[@danielmusat597]

Usually you don't need the whole schematic. In this case though, it is nice to have it. But you should know how to use it. That stand-by chip usually is at fault when it is hot. This time it was not. You certainly have a short on the 3.3V LDO side which feeds the RTC and a small part of the ECU. If you look in the schematic you can find that J... that you de-soldered and follow the line until you find the problem. The short on the feed-back line is your fault solely. You didn't assemble the chip correctly and made the short under the chip. That's why it disappeared when you removed the chip. When you have such a problem, remove the chip and make sure there are no shorts on LDOs first. Then reassemble the chip. Then look for enable pins for 3.3 and 5V rails. Then check to see if 3.3 and 5V are present. It was not the case here but this is the way to do it. Cheers!

[@mohammadmansour695]

Hello dears, I have a Dell Inspiron N5110 with no display problem. The main power LED is lit (on power key/and front LED) when plugged in or on Battery but nothing is displayed, CPU Fan is ON and heat is felt after a while as normally running laptop. I am posting this comment on this video because the problem occurred just after plugging a USB WIFI stick into one of the USB ports. I tried to output on an external display but that did not work. I watched few of your videos and I was really impressed with your way of explanation and analysis. I do not know your name yet, but can call you the Smart Guy. If you do not mind let us Fix this Dell as well. I disassembles the laptop, and examined visually any burnt components on the VGA/USB parts, but could not find any thing. What are your recommendations and guide lines to find the fault?

[@m3dcf]

To quote Sorin from Electronics Repair School: "my thing to find the short is the brute force you know like the savage way ..." The true Master of PCB repair philosophy in glory action at [kzbin.info/www/bejne/r33Jl5eNnaeZfLc @18:12]

[@ikativan2110]

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

[@galvani4987]

I see how this is a fail video. It says "rabbit hole" on the title, I've watched it until the very end and saw no rabbit. Also, the mad hatter didn't have one of his hats on! That... can't be good, can it? And what about Alice? I am not Alice. Are you Alice? Where did Alice go? Did the rabbit took her? Oh, that's confusing... Fail indeed! Boo-hoo!

[@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.

[@andrasszabo7386]

So you say that you don't see socketed CPU nowadays? Then open up an HP Elitebook 8740 where I have just shoved in the most powerful i7 and a 2 GB nVidia GPU.

[@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

[@ottodachat]

done w/ graphix cards, preheat oven to 260 F or 100 + C, leave mother board in oven for half hour, cool down for 3 days and boot. Last chance sort of like finding a cure for covid, anything but cleaning solvents

[@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

[@robinrochan9301]

Hi very nice video I learnt so much from you Is not failure videos video because Behind every failure. We have bigger success thanks 😊 👍👍

[@laptopDoctorKZN]

Hey There can you plese explain 1. Finding Shorts. 2. how 3.3v and 5v is created thanks buddy :)

[@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?

[@Mikie1959]

I wish you lived Closer to me i have a laptop that has me stumped i have replaced the motherboard, the memory ,the hard drive, the CMOS battery, LCD Screen disconnected hard ware and still all it does is just turn on and the fan spins i don't know what else to try.

[@jojitnartates2469]

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

[@ionutnedelea780]

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

[@gustavocontreras6202]

Very good video, not all motherboards can be fixed, but this is a great video anyways, thanks

[@phillipboucher4338]

Hi your videos would be so much more entertaining if you spoke faster and stop waffling, also please stop calling us interwebs as it's stupid and condescending.

[@babydust2me205]

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

[@eugenenault4935]

Use your bench power supply set for about 1 amp and voltage at 8 volts volts and check amp draw.

[@clems6989]

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

[@kikershadow]

same problem but laptop power on and no usb portrs show smd paralell short y remove but its ok same inject voltage but nothing satelitte c55t b

[@kwong83]

Looks like the voltage regulator spun 90° when you blew it with the hot air and it ended with the wrong pinout

[@trlababalan1586]

Lol mate. You talk about the feedback line yet you never had a look at the super IO chip that was staring you at the face all that time?!

[@Fixingthingz4u]

Flux my man Flux good job keep em coming :)

[@alessandrozax]

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

[@Martin-ot7xj]

Hi Graham, please make a tutorial video , about how to read schematic for beginners . thnx

[@malikg4u]

Love ur skills thats where badly need Heat camera to pin.point problem and

[@baghdadiabdellatif1581]

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

[@ChishanFipz]

Once, Toshiba made the best laptops. Still use a libretto for ecu programming

[@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.

[@richardmills5450]

Fabulous attempt youre never going to fix everything. cheers

[@drutzi7364]

exactly but exactly same problem my laptop had now it is working back up

[@Cordiaturbo]

I have the same chip getting hot and I too replaced it and it made no difference. Still working on it. ...

[@robinsattahip2376]

Ebay or Ali Express, what a choice, nothing but quality.

[@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

[@weerobot]

No CPU Ziff Socket Backward Step to me...that board bit of a mare...

[@QsTechService1]

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

[@metech-modernelectronics968]

You have to inject the 5 volts and the 3 volts coil so that you can find what is getting hot

[@fredwooding6662]

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

[@josepeixoto3384]

Gottabee the bad smoke inside ,gotta let it out with some electricity; get daboard,we wanna see that at close,you owe us that.

[@SSchaeneman]

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

[@vincentvalentine5900]

you can try to rework the feedback circuit by not using the same trace on the pcb.

[@petboule2010]

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

[@martinvaughan5953]

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

[@Hagledesperado]

VCC doesn't have anything to do with constant current, it means collector voltage power rail. Conversely, VDD means drain voltage power rail. en.wikipedia.org/wiki/IC_power-supply_pin

[@Adamant_IT]

That makes a lot of sense, cheers!

[@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

[@codcouch1]

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

[@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