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

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Answers

  • Larryodie
    Larryodie Member Posts: 1,931 Community Aficionado WiFi Icon

    Please post snips of the circiuits t hat low ohm caps are in, and post the size & nomenclature.

    DId you check the fuses in the Meter as you'll get funny ohm readings of they are blowing.

  • SafeandSound
    SafeandSound Member Posts: 68 Troubleshooter
    edited November 2024

    The caps circled in black, blue, purple and cyan are the ones with low resistances. Here is a photo for reference:

    image.png

    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 same circuit according to the schematic, which is on page 39. Here is an image of the page of the schematic:

    image.png

    The cap circled in cyan is EC16 and has a resistance of 21.7 ohms. The caps circled in purple are EC21, EC22 and EC23 (bottom to top) and they have a resistance of 11 ohms. The schematics for these capacitors are all on page 40, here is a copy:

    image.png

    And finally there is the capacitor in black which we were discussing before, labeled as EC34 with a resistance of 1.5 ohms. Here is a copy of the schematic, located on page 44:

    image.png

    I couldn’t find the IC chip for U35, although I did find the marking in the motherboard. Do you think it has anything to do with the resistors next to it?

    image.jpg
  • Larryodie
    Larryodie Member Posts: 1,931 Community Aficionado WiFi Icon
    edited November 2024

    DID you check the fuses in your meter or double check with another meter ????

    The chip is a UP1537. AS I SAID BEFORE LIFT PIN 8 to verify. You're running circles as I'm typing needless, CHECK YOUR METER FUSES then lift pin 8 or cut the pattern to pin 8.

    All those caps mentioned or in parallel so you're going to start removing feeds to isolate, probably using an Exacto knife to cut patterns or solder suck/solder wick each one BUT CHECK THE FUSES IN YOUR METER use another meter to verify. Blown meter fuses will cause low reading.

    image.png
  • SafeandSound
    SafeandSound Member Posts: 68 Troubleshooter

    My multimeter only has one fuse as far as I can tell and it’s not blown. Here’s a photo of it:

    IMG_0523.jpeg

    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 giving low readings:

    image.jpg

    I believe I also found the chip that is U35. There are two ICs on the motherboard that have UP1537 written on them and the other one has U22 written next to it, here’s a photo of it:

    IMG_0526.jpeg

    but which pin is pin 8?

  • Larryodie
    Larryodie Member Posts: 1,931 Community Aficionado WiFi Icon

    Great, as I was going to suggest that you measures your body resistance. The meter pdf that I posted had 2 ceramic fuses.

    NOW troubleshoot as why the CAP in black shows low ohmage, you'll have to physically trace the land patterns from it (using your snippets of that circuit), it looks like that it feeds pin 8 of U35.

    So lift pin 8 or xacto cut the pattern to pin 8 and see if your short across the black cap disappears.

    It is all elementary trouble shooting from here, just start eliminating the parallel circuits to the BLACK CAP

    Follow the positive lead from the black cap to U35 pin 8 and lift or cut to see if the short disappears as I'm betting on a corrupt U35 from a power surge or static electricity arc.

    The dots and arrows on U35 will give you pin 1 location. Looks like pin 1 is with the arrow but not always true. As I said trace the pattern from the + on the black cp to the IC

    GOOD LUCK, I'm out of here for good as I have some medical problems that require less stress and more rest.

    Remember that you still have the USB problems and the computer is OLD.

    Do you self a favor and trash it, no used MB, just buy new and enjoy the speed and WIN 11'S technology.

  • billsey
    billsey ACE Posts: 36,168 Trailblazer

    I really have to step in to say trying to measure resistance on a capacitor is a gesture in futility. Here is how Fluke suggests they be measured. What you are doing is measuring resistance through the circuit board and that will be radically different at different places in the circuit. You would have to pull the capacitor off the board to measure it without the rest of the circuit throwing the numbers off. Your multimeter should be on the capacitance position on the dial switch, not on resistance.

    Click on "Like" if you find my answer useful or click on "Yes" if it answers your question.
  • Larryodie
    Larryodie Member Posts: 1,931 Community Aficionado WiFi Icon
    edited November 2024

    Deleted by me.

  • SafeandSound
    SafeandSound Member Posts: 68 Troubleshooter
    edited May 26

    deleted by me

  • SafeandSound
    SafeandSound Member Posts: 68 Troubleshooter

    I finally got my hands on a good soldering iron and some solder, and I used them to remove one of the capacitors for testing. The capacitor I removed was EC31, which was one of the capacitors that seems faulty when I measured its resistance in circuit. According to what I saw on YouTube, a good capacitor should begin with relatively low resistance and then begin to increase until it reaches infinite resistance. When I measured some of the capacitors’ resistances in circuit some of them had a constant resistance, however when I removed one of them from the circuit (EC31) and checked its resistance again, I found that the resistance continued to increase until infinite. This would indicate that the capacitor still has correct resistance, which makes me wonder what would cause it to change when it’s in circuit. My multimeter doesn’t have a capacitance setting so I can’t check its capacitance, and when I checked its voltage out of circuit it was about 0.2 V. The capacitors around the USB ports have constant resistances in circuit, which seems to indicate that there is a something going on there, which would explain why the USB ports weren’t working whenever I connected something to it. Is there another way to check if a capacitor is faulty besides checking capacitance (for example if there is a short circuit in the capacitor), and if the capacitors are not showing any problems when checked, what else would cause the USB ports to stop working and the prevent the computer from turning on?

  • Larryodie
    Larryodie Member Posts: 1,931 Community Aficionado WiFi Icon

    The chip is a UP1537. AS I SAID BEFORE LIFT PIN 8 to verify. You're running circles as I'm typing needless,

    LIFT pin 8 of U35 or cut the pattern to pin 8.

    U35 is most likely shorted internally,

  • SafeandSound
    SafeandSound Member Posts: 68 Troubleshooter

    I am not able to lift pin 8 without lifting the entire U35 chip, so I removed L23 which is in series with pin 8 and the capacitor is still giving a very low resistance of about 2 ohms

  • Larryodie
    Larryodie Member Posts: 1,931 Community Aficionado WiFi Icon

    Great but now I'm lost as to where is the source on +V1P0A ??

    The little caps could be shorted too C518, C519, & C520.

    You don't have to remove them, just lift one end up. Desoldering tool or desoldering braid is a must for desoldering.

    image.png
  • Larryodie
    Larryodie Member Posts: 1,931 Community Aficionado WiFi Icon

    What is the source of V1P0A ?

    image.png
  • SafeandSound
    SafeandSound Member Posts: 68 Troubleshooter

    Here is a diagram of the power delivery of my motherboard:

    image.png

    The +V1P0A seems to come from APW8727L, but I couldn't find that device anywhere else in the schematics.

  • Larryodie
    Larryodie Member Posts: 1,931 Community Aficionado WiFi Icon
    edited 1:13AM

    That is the 5V standby line. It goes all over the place.

    Check some 3 pin regulator units with your ohmmeter to see if you find one with all 3 legs shorted (low ohmage)

    In television units the 5V stand-by always went to a microprocessor that lightning had shorted or possibly a zener diode on the input.