You don't have to brute force find clock/data. They both have a zener diode on the battery side. So if you put red probe on gnd and find a voltage drop of .7V or .8V you found data or clock. That narrows down the brute forcing.
Great explanation of the system/battery presence signals and demonstration with the battery analyzer. Just a note, on the schematics R4310 is a series resistor, the pull-up should be somewhere else before that. Burning the trace would have required several amps going through it, it would have burnt the multimeter fuse (at least in mA/µA range, but if the current came from the battery it'd probably have exceeded the 10A of the A range as well) before you could take a reading if the issue was still present. I'm not sure what happened though, maybe someone tried to unplug the battery with steel tweezers and shorted something inadvertently or dropped them on the board. If the battery rail actually got sent there I'd suspect the BMS to be damaged as well. Also, I'd have soldered a very thin and small wire just to link the burnt trace so that it could burn again if there was still something wrong. With a thicker wire you run the risk of something else burning, for example a via which would burn the PCB internally as well. (here there's still a decent length of thin trace that could burn but you never know)
As always, a really good video with you explaining along the way. This in particular was good because of your in depth explanation of the communication between battery and motherboard. One more thing you have that some other vloggers lack and that is humility. You are so humble despite your knowledge and ability to explain. Keep up the good work and cheers to you and your team. Best regards Magnus
@Adamant_IT I had guessed this was caused by a shorted TVS diode on the data, clock, or battery present lines, but I guessed wrong. The Inspiron 550x-series may not even have TVS diodes on those lines. You really should open that battery. It is fairly simple to remove the hard plastic shell over the PCB, so you can examine it. Thanks very much!
Excellent content and another laptop fixed and back in the hands of the customer, what a great crew too, especially the guy that stands around holding a fire extinguisher just in case of IGNITION
Very interesting video. Such an odd failure mode. To me the trace didn't even really look burned, more like a physical incident. Bit of constructive feedback: at times it was very unclear to me which battery is connected at the moment (when you were measuring the sys detect current). Just clarifying each time which battery you were connecting would have helped a lot. Also I would've loved to see what would've happened when plugging in the old battery after fixing the trace. Although I get that that's a bit risky. Keep up the good work! :)
Maybe what happened is actually that the battery was connected and disconnected for some reason in the wrong way otherwise it doesn't seem to make sense why track blew up like that. Great video Graham!
Might have just been corrosion too, the resist looks to be missing rather than burnt off. Sometimes on a pcb the copper can be contaminated right at the beginning of manufacture.
Strangely enough, every Latitude 7490 I've seen (and it's been quite a lot), I've had to replace the battery, as it's turned into enough of a spicy pillow so as to push the bottom of the laptop apart. It hasn't happened on any other Latitude I've seen, only 7490's (and a handful of 7390's).
Some Dell laptops will not charge aftermarket batteries unless the settings are changed in the bios settings. Some Dell's are shipped in "Fast charge' setting by default and will not charge some aftermarket batteries unless the setting in the bios is changed to the 'Standard' setting.
LoL, I've never encountered such a case, so I never went into such detailed inspection of how the battery is connected. I knew that laptops and other devices communicate with the battery, but I never really cared about how it worked or how to use that information, even though I have flashed firmware in a laptop battery to tell it that it has new cells. Very interesting video, at least to me.
Great video. 👍 Though one thing puzzles me on this particular laptop is: The BMS handles the battery side of current, data, and clock sense pin information, what IC handles the motherboard side: The PCH?
when you went to measure current and saw nothing, I wondered if you forgot to swap the probe lead on your DMM from voltage / resistance to current. The camera doesnt show the DMM lead inputs, only the screen. Only at 17 mins into the video, so if this was the case, I will see if you notice or not as the video progresses
Hey. It would be nice if you could make a new version of that system maintenance/troubleshooting/windows clean up video that you did a while back. It was very useful, and really needs an update. Cheers.
Yes! Not a huge amount as I'm not super into retro stuff, so while I liked everything I was seeing, I had no idea how to start conversations 😅 However we exchanged email addresses and stuff, and I hope to do some kind of collaboration in the future 👍
quick question about bateries mr graham, how thrustfull is the reading of "batery health" on a simple software as batteryinfoview? i replaced the batery on my laptop and in just a couple of days it went from 100% to 82%, and im starting to doubt about the "new" condition of the new batery
Battery health basically means "The battery is designed to be 10,000mAh. The last charge cycle measured 8,000mAh. Therefore the battery is at 80% health." It's a reasonably good indicator of overall health. I consider 80% and under to be significant degradation, so a 'new' battery dropping that low so soon sounds like a faulty unit. Try running the battery to empty and then full charging it (one full cycle) so its BMS can recalibrate and see what the health updates to, but yea, sounds like a bad unit.
I had this issue on a Lenovo legion 5 just opened the device disconnect the battery and press power button to discharge then reconnect the battery and it started charging and using the battery!
Done watching, thank you very much for the informative repair video. I have learned significantly more troubleshooting & repair lessons in this tutorial video and to your other repair videos as well compared to my ENTIRE 4 YEARS OF COLLEGE due to the rotten & outdated standards of education here in the Philippines. I hope you will soon have a mini-series for Schematic & Boardview-free Voltage/Power Rail Tracing[12V/18-20V Main Voltage Rail, 5V, 3.3V, CPU/GPU Core Voltage Rail, DRAM Voltage Rail, IGPU Voltage Rail, System Agent/Northbridge Voltage Rail, PCH Voltage Rail, BIOS Voltage Rail, Battery Power Rail], Proper method of testing/checking of potentially faulty MOSFETs & ICs/Controller Chips, CPU/GPU/PCH Reballing and BIOS Bin File Editing.
@@Adamant_IT thanks for replying. I had asked why I have the problem that lately it keeps restarting (MSI Z77A G43) I'm trying to test mosfets and capacitors with a digital multimeter but I don't have much knowledge
when looking for interesting videos to make.. you can buy this "USB killer" dongle and zap some laptops. it would be interesting to see how badly damaged/repairable they are after that treatment. even old ones. ;)
You don't have to brute force find clock/data. They both have a zener diode on the battery side. So if you put red probe on gnd and find a voltage drop of .7V or .8V you found data or clock. That narrows down the brute forcing.
Great explanation of the system/battery presence signals and demonstration with the battery analyzer. Just a note, on the schematics R4310 is a series resistor, the pull-up should be somewhere else before that.
Burning the trace would have required several amps going through it, it would have burnt the multimeter fuse (at least in mA/µA range, but if the current came from the battery it'd probably have exceeded the 10A of the A range as well) before you could take a reading if the issue was still present. I'm not sure what happened though, maybe someone tried to unplug the battery with steel tweezers and shorted something inadvertently or dropped them on the board. If the battery rail actually got sent there I'd suspect the BMS to be damaged as well.
Also, I'd have soldered a very thin and small wire just to link the burnt trace so that it could burn again if there was still something wrong. With a thicker wire you run the risk of something else burning, for example a via which would burn the PCB internally as well. (here there's still a decent length of thin trace that could burn but you never know)
As always, a really good video with you explaining along the way. This in particular was good because of your in depth explanation of the communication between battery and motherboard. One more thing you have that some other vloggers lack and that is humility. You are so humble despite your knowledge and ability to explain. Keep up the good work and cheers to you and your team. Best regards Magnus
@Adamant_IT I had guessed this was caused by a shorted TVS diode on the data, clock, or battery present lines, but I guessed wrong. The Inspiron 550x-series may not even have TVS diodes on those lines. You really should open that battery. It is fairly simple to remove the hard plastic shell over the PCB, so you can examine it. Thanks very much!
Great repair video definitely one of my favorites and hello to Sy, Muerto, Carradog and especially Catriona.
Excellent content and another laptop fixed and back in the hands of the customer, what a great crew too, especially the guy that stands around holding a fire extinguisher just in case of IGNITION
I saw that battery tester and thought I was watching Sorin!! Nice job!
I wish they were available at a lower price, but it is a professional tool, with active support from its creator. Not for hobbyists.
Always a good sign when it doesn't catch fire!
Dude I love your channel. They way you explain everything is so beginner friendly!
Great work as always Graham. Thank you
Very interesting video. Such an odd failure mode. To me the trace didn't even really look burned, more like a physical incident.
Bit of constructive feedback: at times it was very unclear to me which battery is connected at the moment (when you were measuring the sys detect current). Just clarifying each time which battery you were connecting would have helped a lot.
Also I would've loved to see what would've happened when plugging in the old battery after fixing the trace. Although I get that that's a bit risky.
Keep up the good work! :)
Maybe what happened is actually that the battery was connected and disconnected for some reason in the wrong way otherwise it doesn't seem to make sense why track blew up like that. Great video Graham!
Might have just been corrosion too, the resist looks to be missing rather than burnt off. Sometimes on a pcb the copper can be contaminated right at the beginning of manufacture.
Strangely enough, every Latitude 7490 I've seen (and it's been quite a lot), I've had to replace the battery, as it's turned into enough of a spicy pillow so as to push the bottom of the laptop apart. It hasn't happened on any other Latitude I've seen, only 7490's (and a handful of 7390's).
Some Dell laptops will not charge aftermarket batteries unless the settings are changed in the bios settings. Some Dell's are shipped in "Fast charge' setting by default and will not charge some aftermarket batteries unless the setting in the bios is changed to the 'Standard' setting.
LoL, I've never encountered such a case, so I never went into such detailed inspection of how the battery is connected. I knew that laptops and other devices communicate with the battery, but I never really cared about how it worked or how to use that information, even though I have flashed firmware in a laptop battery to tell it that it has new cells. Very interesting video, at least to me.
A very interesting repair good job.
Great video. 👍 Though one thing puzzles me on this particular laptop is: The BMS handles the battery side of current, data, and clock sense pin information, what IC handles the motherboard side: The PCH?
The EC does this kind of low-level hardware stuff. Then the EC talks to the power management chip and tells it when to charge the battery and stuff.
Wow nice team work ❤
when you went to measure current and saw nothing, I wondered if you forgot to swap the probe lead on your DMM from voltage / resistance to current. The camera doesnt show the DMM lead inputs, only the screen. Only at 17 mins into the video, so if this was the case, I will see if you notice or not as the video progresses
Hey.
It would be nice if you could make a new version of that system maintenance/troubleshooting/windows clean up video that you did a while back.
It was very useful, and really needs an update.
Cheers.
Wow see all your production team and even caredog!
Could you possibly do a video on an hp(or any) laptop that randomly reboots itself?
Had the same problem the guy changed the motherboard i was like no you need fo change the battery oh boy he was right.
I was there when the sausage was made! Great honour!
Great Video Graham - hope you guys enjoyed coming up to my part of the country and visiting RMC - do you get a chance to talk with Neil?
Yes! Not a huge amount as I'm not super into retro stuff, so while I liked everything I was seeing, I had no idea how to start conversations 😅
However we exchanged email addresses and stuff, and I hope to do some kind of collaboration in the future 👍
Cool that'll be interesting.
quick question about bateries mr graham, how thrustfull is the reading of "batery health" on a simple software as batteryinfoview? i replaced the batery on my laptop and in just a couple of days it went from 100% to 82%, and im starting to doubt about the "new" condition of the new batery
Battery health basically means "The battery is designed to be 10,000mAh. The last charge cycle measured 8,000mAh. Therefore the battery is at 80% health." It's a reasonably good indicator of overall health.
I consider 80% and under to be significant degradation, so a 'new' battery dropping that low so soon sounds like a faulty unit. Try running the battery to empty and then full charging it (one full cycle) so its BMS can recalibrate and see what the health updates to, but yea, sounds like a bad unit.
@@Adamant_IT Agreed. I toss any battery below 75% health. The built-in Dell diagnostics is very helpful with this, as it shows detailed system stats.
I had this issue on a Lenovo legion 5 just opened the device disconnect the battery and press power button to discharge then reconnect the battery and it started charging and using the battery!
Hello
Can you tell me please what model is your phone? It has thermal camera, right?
Thanks
Well, I think restoring the burnt trace with a much thicker wire is not a good idea.
Plenty of thin wire on the rest of the trace 👍
Good one 😊
"I've changed multi-meter, there is a fuse blown in that one"
"Now lets measure the current"
Completely unrelated sentences!
In my defense, it was already blown before this video 😅😅😅
oh that is what you were doing on Saterday night boozing on hahaha good fix to by the way
You might have had a different amp reading if you put the pins across the break in the wire.
They are electrically connected to the same points.
@@jaro6985 I don’t think so else it could have been connected straight to the big ground on the 3 pins
Done watching, thank you very much for the informative repair video. I have learned significantly more troubleshooting & repair lessons in this tutorial video and to your other repair videos as well compared to my ENTIRE 4 YEARS OF COLLEGE due to the rotten & outdated standards of education here in the Philippines. I hope you will soon have a mini-series for Schematic & Boardview-free Voltage/Power Rail Tracing[12V/18-20V Main Voltage Rail, 5V, 3.3V, CPU/GPU Core Voltage Rail, DRAM Voltage Rail, IGPU Voltage Rail, System Agent/Northbridge Voltage Rail, PCH Voltage Rail, BIOS Voltage Rail, Battery Power Rail], Proper method of testing/checking of potentially faulty MOSFETs & ICs/Controller Chips, CPU/GPU/PCH Reballing and BIOS Bin File Editing.
What microscope do you have?
Issues with Dell laptops; sometimes the charger itself is faulty and does not change the battery.
why does the battery have 3 positives and 3 negatives and not just one of each ?
Current handling. Need to push or pull 40watts through those pins, a single pin would burn up.
Watching this on a Dell Vostro5568 . 👍
Great team, except for Carry Dog of course 😂😂😂😂👍
Do you also repair PC motherboards?
Naa. I've dabbled a couple of times, but PC mobos are usually horrible rabbit hole issues that I don't have the experience to tackle.
@@Adamant_IT thanks for replying. I had asked why I have the problem that lately it keeps restarting (MSI Z77A G43) I'm trying to test mosfets and capacitors with a digital multimeter but I don't have much knowledge
love the video
How many latitudes did Sy sell while you were busy with this repair?
None. Useless. Just here to sabotage me.
Good morning
when looking for interesting videos to make.. you can buy this "USB killer" dongle and zap some laptops. it would be interesting to see how badly damaged/repairable they are after that treatment. even old ones. ;)
Steve Porter "Tronicsfix" did exactly that with all the devices killed by Austin Evans.