Dell E7470 motherboard repair, a hard one - Part 1

[markkay]

3 years have past now since this vid was released. I believe most dell repairmen would know by now, that this chip CD3301B is not generating 3.3v . This so called "power management" chip is simply controlling key power Mosfets on the motherboard. It is actually quiet easy to bypass this chip and remove it completely from the MB. The main power rail on this MB is +13.5 volts, when AC is in use and +8V or so when on battery. But since chip was getting hot it was the right decision to replace it anyway. Thanks for the great vid Sorin!

[saciu]

33:12 schematic from polish forum Elvikom ;) Greetings from Poland. Ive found your channel when I had same problem with no backlight in Lenovo laptop after changing screen. Keep up the good work!

[yosef]

Sorin you teach the best, I broke my laptop and while I couldn't fix it myself I have learned so much and I will continue to learn until I master the basics

[dazuk]

Hey dude, I love the way you keep things simple, uncomplicated and in a language that can be understood. Computer Technicians time is expensive, and rightly so...when I blew my board, I found the cheapest option was to swap it out for a refurb..an option that should be considered by those in a similar place. Respect my Man, Peace

[sector]

Well that's a bit discouraging, there is no solid knowledge of electronics in an industry that evolves everyday. Every engineer comes with something new. I am glad that i found this channel, keep up the good work. Si ma bucur ca sunteti Roman de al meu si faceti treaba buna. Toate cele bune!

[kztech]

Seems like I have the same fault for a a latitude D830 (iGPU). But unlike you, I am extremely lucky because when handling the board I realised putting my finger in one of the spots make it work perfectly and releasing shuts it down immediately. So my solution was to solder a 200KOhm resistor at that place (the resistance of my skin over that length) and it works just fine lol and it's only now I think it's the same problem as this

[AgentElectronics]

I think the parts marked PL you speak of, that look like resistors, are in fact just ferrite filters used to stop high frequency noise getting from each power supply back into the main 19v rail.

[graffygerry]

A PL is not a carbon resistor, at high frequencies a carbon resistor will have a significant parasitic inductive component but it will not behave properly when dealing with high power due to the resistive losses that this the CR would have (also capacitive parasitic components). PLs(power inductors) could be used in for example DC-DC converters, where efficiency is key as they have low ESR.

[juanchizabaleta]

Thank you very much master for showing the reality of reparations. Greetings from his disciple from Argentina.

[tgordy]

Great job on the videos and thanks for posting them!

[rotrose]

Thank you very much, I like your approach so much, and definitely learnt a lot from you. Please continue the repair project with your style.

[freddiemortos]

PL = Power Imductor. L is a sign of an inductor(coil).

[burhanuddin]

I know sorin doesn't needs any one's suggestion but downloading schematic saves plenty of time...

[MyOwntuahur]

Thanks for all knowledge that you give..

[gile]

Omg. Part 1. thas mean its very hard one :D But Sorin fix it 100% Stay tune foks for other parts. Sorry my bad eng

[AnonymousRepair]

CD3301B controls if the power comes from the doc connector or the dc in plug, time 35:00

[mikeheiss]

I watch ya few times on tube I have tried fix 5 so far laptops the alienware one I'm on oh gosh mess hair dust clean clean and then vac6 breaks dang oh well keep going thank you for info

[computersrepaircotesaint-l]

oops missed this one, never missed any vid yet

[MrRvdbeek]

Amazing what you are doing with your knowledge and experience. Whiteout a schematic of the board finding the problem of the 3.3v power rail. Thank you for the great work and i watch the next video 👍🏻. I did watch the video again and again don’t understand why you find the 3.3v it’s not a normal laptop and I don’t have experience with the broken chip.what is it doing?

[asharbinkhalil]

Need Help from motherboard experts.

My Dell e7470 was damged from dock area. All motherboard is working fine and laptop is booting but the dock area gets very hot and spark.

I don't want to dock in my laptop. Is there any way that i can disconnect the dock area from power.

The dock area is a separated slice in motherboard.