Nvidia Shield Portable charging port help - SMD component value question

[jburger]

Hi everyone,

I posted this question on Nvidia's GEFORCE forums about two weeks ago and didn't get any answers yet, so I thought I would cross-post my entry here.

My Nvidia Shield Portable's micro USB charge port broke off, and I need to solder on a new one. I bought replacement micro USB ports on eBay, but another very small SMD component right below the charge port also broke off. I have enclosed a stock picture with 3 red arrows pointing to the SMD component that broke. Its two solder pads are still intact.

HERE IS THE PICTURE:

What is this component? Is it a charging port fuse? Or a capacitor of some kind? Does anyone know the value and size of this SMD component? I.e., the voltage and micro/picofarads if applicable, or from similar electronics PCB designs if applicable? Or fuse ratings if it is a fuse? (Note that the Shield Portable is battery powered by a 5V 2A charger.)

Can I take this component from elsewhere on a spare (bad) Nvidia Shield Portable motherboard? I have one spare Shield with a bad screen connector port that I kept for parts only. I successfully desoldered this small component from the spare motherboard with tweezers, only to have it fly across the room never to be found again, as the tweezers slipped when I was tinning the component. So I lost two of these very small components in total. I looked everywhere for it, sadly, in between floorboards and what not, but had no luck finding it.

Is this small component under the charge port absolutely necessary for the device to still charge (safely) and function when I solder on a new charge port? Thanks so much for your time and help.

 

[ronsimpson]

Not enough information. Picture needs to zoom a lot.
My guess is it is a capacitor on the +5 volt pin on the USB connector.

 

[jburger]

Thanks, ronsimpson, for your help!

I thought it was a capacitor of some sort as well. I don't suppose this other picture from the web is any better? I suppose you are looking for tiny markings on the component as to its value?

Any guesses as to the capacitor's function? The Micro USB has a fourth Mode ID detect pin, which may tie into an orange/green light on the other side of the circuit board when it is charging/fully charged. It could also be the +5 volt pin that powers the orange/green charging indicator light.

I am not too concerned about the charging indicator or Mode ID detect once I solder back on the micro USB, only that the system charges fully.

 

[Diver300]

It's almost unheard of for capacitors like that to be marked with a value.

My guess is that ronsimpson is correct, and that it's a decoupling capacitor on the 5 V rail. The colour is a clue. Capacitors like that are usually X7R dielectric and look like that. Lighter colours can indicate other dielectrics that allow for more accurate capacitors, where the value is more critical.

If the guess is correct, the value is not important. The circuit will probably work fine without it. Capacitors like that are added on every IC, as it's a good thing to do and can't hurt, but it's very unlikely that anyone has bothered to optimise values or work out whether every one is needed. The value will probably be 10 or 100 nF, and one that looks the same from the spare board will probably be correct or close enough.

 

[jburger]

Diver300 - Thank you so much for your post. It is super helpful.

I will be attempting this micro USB resolder project sometime this week using the breakout board below, since that will be easier for me with the micro USB already soldered onto the blue PCB. I will put on a matching color and size capacitor on the 5V rail (I'm eyeing the one on the left-hand side of the rectangular black -V component in my post #3 above.

I will post my results upon completion.

 

[TommyBr]

That's a hard part to try and repair. Curious how it went...

 

[jburger]

Well, here is a much belated update for anyone interested.

Originally, I had replaced the charging port on this Shield Portable with a new one from eBay. This worked to charge the device for a month or so, and then the resoldered port broke off. There were several pads lifted after the break, when I originally posted this thread, but 5V and ground were still intact. This is what the pads looked like:

My unsuccessful attempt at fixing this involved soldering a red wire to the 5V pin and a black wire to a nearby ground pad. I soldered the other wire ends to a PCB breakout board after drilling a hole through the back of the shell casing. I didn't have Mode Detect, D-, or D+, so those were ignored. Also, the only bypass points for Mode Detect, D-, and D+ that I found on my spare board were too small to solder to on miniature IC pins near the charge port.

Here is 5V and ground soldered, which I later covered with white silicone rubber adhesive and let dry:

I found it was too difficult to solder another tiny capacitor from my spare board to the one missing on the 5V rail, so I left that part out.

Here is what my project looked like after soldering the wires to the breakout board and gluing it down:

I plugged in a good 5V 2A micro USB charger into the new breakout board port and let the unit sit for a few hours in sleep mode at 75% charge. I noticed there was no charge to the battery pack after a few hours of letting it sit (battery life actually decreased to 74%). I was thinking perhaps the red 5V wire came loose on the motherboard and peeled off bits of the white silicone cured adhesve to get to the 5V pin.

Unfortunately, this and other messing about at the hinge caused the delicate screen ribbon cable going to the LCD and digitizer to break. It was unrepairable for me after that. I looked and there were no spare LCDs available for this older 2013 Shield Portable model on eBay. A used Shield runs about $160.

In retrospect, had the bypass PCB board worked to charge the device--which I think in theory it would have--I would have still been concerned about possible fires or other issues if the console was left unattended. If the 5V pin was bypassed elsewhere on the board, or directly somehow to the battery (dodgy), I would have also been concerned.

I have since disposed of this project and the console entirely. I got a good 7 years or so out of it, so there's that!