What are the voltages for each USB 3.0 header pin of Aspire ATC-710-EB51

Larryodie

Get me a schematic and I'll offer trouble shooting advice.

Larryodie

If the cap in black reads, zero ohms across it then you have found your problem, most likely a feed from it, or the cap itself.

SafeandSound

The cap in black reads 1.5 ohms. Also here is a link to the download page of the schematics for this motherboard, the H11H4-AD2:

ECS H11H4-AD2 REV 1.1 (ACER ASPIRE XC-710), Service Manual, Repair Schematics

Scroll down to where it says Download in a grey box. You may need a browser to translate the webpage for you, like Microsoft Edge. The schematics are in English though.

Larryodie

I download. BUT what # is on the cap in BLACK like Cxxx ??

As I can't read it by your pictures ?

Have you socker sucked one pin of the cap out of the circuit ?

Please give the cap's board # like Cxxx and the coil # or better yet , snip the page from your schematic and post/paste it on here.

Do you have and solder sucker Hakko equipment as you'll need to narrow it down. Please post and paste the snips that correspond with that circuit.

SafeandSound

I haven’t solder suckered anything in the motherboard nor have I attempted any disassembly whatsoever. Here is a photo of the capacitor, it doesn’t have a number like Cxxx but there is a number on the motherboard for it, it’s EC34:

The corresponding schematic is on page 44, here is a snippet of it:

Larryodie

It's written C556 on the mother board.

Please post a snippet of C556 circuit.

Larryodie

820 UF at 2.5 V

2.5V is really unusual for a working voltage.

Larryodie

OK it's is EC34 on your snipped.

You need to desolder (remove) L23 to narrow it down to which way the short lies.

SafeandSound

What do I do after I desolder L23?

Larryodie

See if your short is still present across EC34 (C556).

If the short disappears then you need to de-solder and lift pin 8 of U35 to see if the IC (chip ) is shorted.

You may be able to use an exacto knife and cut land patterns to narrow it down and then repatch them with wire.

Warning if you don't have the tool and expertise, take it to the man.

SafeandSound

How would I check if the IC labelled U35 is shorted after desoldering and lifting pin 8? And what should the resistance of the capacitor EC34 be?

Larryodie

If the short goes away on ec34 by lifting pin 8 then pin 8 inside the chip is shorted. This is basic electronic troubleshooting.

Think of it as you have 10 circuits in parallel to ground . They all read short to ground (zero oms) across them.

The task is to find which of the ten is the bad circuit.

SafeandSound

Here is what U35 looks like on the motherboard, I don’t see any IC on it:

SafeandSound

also the capacitors circled in blue had 3.5 ohms, are they also considered to be shorted, since the one capacitor in orange had 140 ohms? I measured by placing the probes of the multimeter on the ends of the capacitors. Is that the way to check for shorts, or should I be measuring by placing the red probe on the positive end and the black probe on the ground of the motherboard? Because when i check the second way (black probe on ground of motherboard) all the capacitors produce 0.5 ohms except for the ones circled in red, which have no continuity

Larryodie

The chip is under the shield.

When you check ohms on the main board, Be sure that all voltages have disappeared as the caps hold voltages until they're drained.

Leave the board unplugged over night then check if there are any volts present on the board,

Change your battery in the meter.

Put your meter on continuity checking , NOT DIODE.

What meter do you have ??? Buy a good FLUKE meter and a good ESR meter

YOU HAVE A CAP that is dead short as we've discussed, C556, EC34 on the snip. Have you started troubleshooting that DEAD SHORT by lifting pin 8 of the U35

I'm done with this thread, you have your problem solved with the dead short . Just isolate it and replace the shorted item in the parallel path,

Do you have any solder and de-soldering equipment ??

Shopjimmy.com should have everything that you'll need

As I said, I'm done until you've narrowed down the DEAD SHORT across E34 (C556) and GOOD LUCK

Larryodie

Are you disconnecting the power supply from the mother board when doing ohms testing ?

AND put your meter in NON-DIODE testing . Take a picture of your meter please ?

SafeandSound

Under the shield near U35 is the PCH, it doesn’t look like an IC with pins that can be lifted up. Here is an image:

I disconnected the motherboard from power a few days ago. Also I am using resistance mode at 200 ohms in my multimeter, here is a picture of it:

Larryodie

Those cheap WalMart meters are actually very accurate. The 2000 ohm range should be for diode testing.

There is 2 small fuses in the back of it that are confusing when they open as I remember they will give you false ohms readings. Check them to be sure.

By your last post all of the caps are now .5 ohms except the ones in RED ???

Better check the fuses in the rear of the meter. Then check again because your earlier posting didn't indicate but one shorted, "C556"

Check the fuses in your meter, you'll need a second meter to check them. I always kept a analog meter nearby.

https://www.manualslib.com/manual/1460021/Mastercraft-052-0060-2.html?page=20#manual

Larryodie

Also you need to be check across the caps not to Ground as you speak. Most all of the caps will have the negative end going to ground but not BOTH leads.

Some caps may have the positive lead to ground if they're on the MINUS - 12V supply.

SafeandSound

ok I wanted to confirm that I had to check across the caps and not to ground. In that case the cap circled in black in the previous post has 1.5 ohms, the caps in blue have 3.5 ohms, the cap in cyan has 21.7 ohms, the cap in orange has 140 ohms, the caps in purple have 11 ohms, the cap in white has 96-97 ohms, the caps in yellow flash continuity very briefly between 40-180 ohms, and the caps in red have no continuity.

Also I checked under the shield near the U35 marking on the motherboard and there I found the PCH, which does not look like an IC. Here is a picture of it:

Any idea where the IC chip is for U35?