SafeandSound Troubleshooter

My multimeter only has one fuse as far as I can tell and it’s not blown. Here’s a photo of it: I don’t have another multimeter to verify the readings this one is giving for resistance, but I measured the resistance of my finger, switching the range to 20M ohms and it bounced around a few million ohms, so I don’t think it’s…

The caps circled in black, blue, purple and cyan are the ones with low resistances. Here is a photo for reference: The caps circled in blue are labeled EC14, EC15, EC12 (below the CPU, right to left) and EC17 and EC18 (left of CPU, bottom to top). They have the same resistances, measured at 3.5 ohms, and they are in the…

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…

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:

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…

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

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?

What do I do after I desolder L23?

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:

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…

I tested for continuity between the A/C ground pin of the PSU and the black wire pins of the 24 pin connector and they had continuity at about 0.5-0.7 ohms. I tested for continuity between the black wire pins of the 24 pin connector and the computer chassis and got the same results. I also tested for continuity between the…

I also checked the resistances of each capacitor by placing the red probe on the positive end and the black probe on the negative end of the capacitor. Here is a picture of all the capacitors I checked circled in different colours: The capacitors circled in red had no continuity, the ones in yellow had continuity for less…

I checked the capacitors on the motherboard by placing the black probe on the ground of the motherboard and the red probe on positive end of each capacitor and measured ohms. All the capacitors except for the four near the audio chip had about 0.5 ohms, while those four had no continuity. I don’t know what the resistance…

here’s another one of the one behind j13, labelled c33

I took another look at the capacitors, none of them are domed. Maybe some pictures from another angle may show what I mean:

I measured the voltages of pins 10 and 11 of the 24 pin connector both with the ac power connected and disconnected to the PSU and both yielded zero volts. I also saw another 4 pin connector coming from the PSU that I believe is also a 12 V line, it looks like this: I measured the voltages of the pins both with ac power…

According to the schematic in the previous post pin 54 is ground and pin 53 is AVCC. I don't think I can separate the GPU from the CPU as they are integrated, and there is a metal slab stuck to the top of it with some kind of adhesive. This is what it looks like:

When I checked the voltages of the pins of the Super I/O pressing the on button didn't change the voltage readings. Pins 28 and 29 had 2.90 V, pin 33 had 5.17 V and pin 34 had 3.56 V. None of them had 12 V and no burning odour. I also used pin 44 as ground and when I contacted pin 53 with the red probe it had continuity of…

I checked the resistances of pins 49 to 52 by contacting pin 54 with the black probe (which goes to ground according to the schematic) and contacting the other pins with the red probe. What I found was that pins 50 to 52 all had no continuity, but when I contacted pin 49 it would show continuity for less than a second. I…

I plugged the 24 pin atx power supply cable as well as the 12 V atx cable into the motherboard and when I touched the PCH you were referring to it was not hot. I think the picture I took may have been misleading as my shadow was over it when I took the photo, so it appeared darker than it actually was. Here is another…