Aspire TC-895-EB11 Power Supply Audible Noise

DJMikoss
DJMikoss Member Posts: 12

Tinkerer
edited March 1 in 2020 Archives
Hey everyone,

I recently purchased the Acer TC-895-EB11 and it is working properly, however the power supply is extremely noisy. 
Power supply specs:
Liteon 500W 80+ Gold
PA-4501-1AC-ROHS
Mfg Date 2020/03/11

The noise is audible noise which sounds like a slight ticking sound (almost like an old, spinner HDD which is moving data). It also progresses into quicker ticking noises, almost like a static noise, which is audible in a quiet room. It makes the ticking noises regardless of whether the computer is off (in standby), or powered on. When the machine is powered on, the audible noise increases with load... eg loading a webpage will cause the noise is vary in frequency/volume level, and will subside once the page is loaded.

It is not the fan, it is not anything else inside the desktop, it is most definitely the power supply.

I suspect it is either a capacitor, or inductor which is causing this noise... this is a switched power supply, so it may also be the MOSFETs which are causing the noise.

It also seems like all of these desktops are producing the same noise from the power supply... the issue is covered in a thread on redflagdeals, since the computer went on sale at Best Buy Canada.

Looking at the motherboard, the power supply connects to the CPU via 2x 4 pin connectors. This is standard and fine.

The other power connection is via a very special 6 pin power connector which is not PCI-E. I saw in another thread that the pin out for this connector includes two +12V pins, two grounds, and PS_ON#.

I take it that there is no way for me to replace the power supply with a standard ATX power supply, since this motherboard uses this special 6 pin connector. I also assume that this power supply is special, in that it supplies 12V while in standby, and then when PS_ON# triggers a signal, it will provide 12V to the CPU.

I cannot find a replacement part online for the power supply, and Acer has issued me an RMA to send the computer back, however this is basically a 1 month turn around, and seems like I may just end up with another noisy power supply.

Does anyone know if it's possible to use a regular ATX power supply, and simply change how it is connected, so that it works with this motherboard? I would much prefer to simply do this, than to send this out to Acer. I tried to isolate the source of the noise in the Liteon power supply, and cannot determine which component is making the audible noise.

Answers

  • billsey
    billsey ACE Posts: 34,236 Trailblazer
    There is a fan inside the power supply, and I suspect it.
    Click on "Like" if you find my answer useful or click on "Yes" if it answers your question.
  • DJMikoss
    DJMikoss Member Posts: 12

    Tinkerer
    edited September 2020
    I covered that Bill. It isn’t the fan. 

    The power supply has a component which is making the noise. The component on the power supply pcb makes the noise even with the power supply fan completely disconnected. 

    If you’d like a video so you can see that it isn’t the fan (which is quite evident when the fan is disconnected) and hear the noise, I can post one. 

    In the meantime, is it possible to get a power supply which would replace this faulty one? Still wondering about my questions above, regarding standby power and 12V. 

    Thanks!
  • ttttt
    ttttt Member Posts: 1,947 Community Aficionado WiFi Icon
    @DJMikoss

    Your case is little difficult. If I were  you, I'll search hard for PSU that has this kind of special 6-pin non-PCIe connector and low noisy rating. If this is still not available, then I'll try to find conversion cable/wire from regular PCIe, Molex or SATA connectors to this kind of 6-pin non-PCIe connector (probably need "Y" connector for Molex and SATA). Hope you can find one.
  • DJMikoss
    DJMikoss Member Posts: 12

    Tinkerer
    Ok, so I need to know if a regular ATX power supply will put out the 12V required for standby?

    I am not a computer specialist, but it's my understanding that a normal power supply does not put out 12V in standby, and only turns on the 12V power when the PS_ON signal is triggered.

    I have no idea how this Acer works, since searching up the motherboard shows no information online. My assumption is that this Acer requires 12V from the power supply while it is in standby mode, and when the power button on the case is pushed, the PS_ON signal is triggered, and the power supply will supply 12V to the CPU, to turn on the computer.

    So, using a spliced in cable/splitter to wire onto the Acer's motherboard does not seem to be a solution. Unless a regular power supply has a wire which is providing the 12V necessary during standby mode? It's my understanding that the specification is 5V for standby power.

    Acer seems to have created their own power supply scheme, however it's difficult to understand without having any documentation regarding the motherboard or the power supply. That's why I'm asking here.

    I wrote that it wasn't the power supply fan, and yes, it would be the most likely culprit for noise, but that simply isn't the case. The audible noise is not normal and not acceptable... I'll post a video so that you and Bill can hear it. If this computer was in your house, I'm sure you'd worry that something was wrong with the power supply.


  • DJMikoss
    DJMikoss Member Posts: 12

    Tinkerer
    https://youtu.be/flBIoAI7bME
    This is the noise the power supply makes... the noise stops when there are no active tasks. The fan is not running during this video, and doesn't normally run, however it will run if the power supply gets hot, and the fan is very quiet.

    The noise sounds like a ticking sound when the computer is in standby mode, and escalates into rapid ticks/an audible sound like static, as heard in the video. The noise isn't coming from the CPU, the CPU fan, the HDD, the motherboard's speaker... it is definitely coming from a component on the power supply. I cannot tell which component it is - I suspect it is one of the capacitors, but it could be coming from a soldered connection or perhaps a fuse?

    I have returned the computer to Best Buy tonight for an exchange... waiting on the new computer to arrive next week. I'll let you guys know if the power supply on the new one has the same audible noise. It seems that reading online, this is a common issue.
  • ttttt
    ttttt Member Posts: 1,947 Community Aficionado WiFi Icon
    @DJMikoss

    Exchange the PC is the best solution. I thought you have to send it out by mail, wait for repairing, wait for delivery (as you mentioned one month turn around) and you are willing to buy a new PSU  instead of one month without PC.

    Just curious, why you insisting on 12V stand by mode? 
  • DJMikoss
    DJMikoss Member Posts: 12

    Tinkerer
    I'm not insisting on 12V standby... it's the design that Acer chose for the motherboard!!

    Looks like they are using the ATX12VO standard, where there is no 5V standby, and everything is now 12V. 
    https://www.intel.com/content/dam/www/public/us/en/documents/guides/single-rail-power-supply-platform-atx12vo-design-guide.pdf

    I spoke with Acer by chat, and they told me I could send it in for repair, but I checked with BestBuy today and they gave me the option for an exchange.
  • DJMikoss
    DJMikoss Member Posts: 12

    Tinkerer
    Alright got the exchange and the new computer has the same audible noise from the power supply. The noise on this one is more sustained, sounds like electrical arcing from a bad connection. 
  • ttttt
    ttttt Member Posts: 1,947 Community Aficionado WiFi Icon
    @DJMikoss
    So, this is the case of manufacturer using poor quality power supply. Searching for a PSU from different manufacturer with the like kind of power connectors seemed to be the only solution,
  • DJMikoss
    DJMikoss Member Posts: 12

    Tinkerer
    The problem is that it uses a special power supply that doesn’t conform to usual ATX specs. It’s impossible to just swap in another supply. 

    I mentioned this before, but I’ll go over it again. 

    The power supply only has 12V- there are no other rails for other voltages. It also has a special connector which is wired unlike any other power supply. If it was possible to just swap in a new supply I would- but it’s impossible to simply wire a regular ATX supply to work with this motherboard. 

    ATX supplies use different voltages for standby power, and do not supply the 12V that this special supply uses.
  • DJMikoss
    DJMikoss Member Posts: 12

    Tinkerer
    I’m totally open to that solution if you can find me a power supply with 12V output for standby. Feel free to link anything you find. Appreciate the help. 
  • ttttt
    ttttt Member Posts: 1,947 Community Aficionado WiFi Icon
    @DJMikoss

    I have done some internet research with the hope of finding a replacement for you and found nothing. How about having a refund from Best Buy or apply the credit  for another PC if you can? 
  • DJMikoss
    DJMikoss Member Posts: 12

    Tinkerer
    Yeah I could also go that route... I’ll let you know what happens either way. 

    From talking with Best Buy and some other local computer shops, it’s common for Acer, HP and Dell to use “one-of-a-kind” components such as custom motherboards and power supplies. 

    It works well, as long as the components work lol
  • DJMikoss
    DJMikoss Member Posts: 12

    Tinkerer
    So I used the computer all day today. Just about an hour ago, the power supply stopped making noise. Hilarious. 

    I’ll keep this post updated with the status as I use it. 
  • ttttt
    ttttt Member Posts: 1,947 Community Aficionado WiFi Icon
    @DJMikoss
    Good to hear that. Seemed to be a case the PSU needs some break-in period.
  • kqian111
    kqian111 Member Posts: 37 Troubleshooter
    It's really unfortunate that Acer decided to go proprietary on the mobo power connector in this generation. The prior gen TC-885 has standard PSU and standard 24 pin molex connector.
  • ttttt
    ttttt Member Posts: 1,947 Community Aficionado WiFi Icon
    @kqian111
    Actually the TC-885 PSU isn't that standard. The size is standard, but one of the SATA connectors for the DVD drives is a 6-pin connector, a non-standard one. You won't notice unless paying attention or when taking the DVD drive out.

  • kqian111
    kqian111 Member Posts: 37 Troubleshooter
    ttttt said:
    @kqian111
    Actually the TC-885 PSU isn't that standard. The size is standard, but one of the SATA connectors for the DVD drives is a 6-pin connector, a non-standard one. You won't notice unless paying attention or when taking the DVD drive out.

    Actual that is a standard laptop slimline DVD 6 pin power connector. And yeah, it's not typically found in a desktop PSU, but that's an easy fix with a $2 SATA to slimline power adapter off ebay, which I ordered. Unfortunately there is no easy fix for the 6 pin proprietary power to the mobo in the TC-895. This really hampers any real chance of upgrading to a discrete GPU that requires separate power.

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