Diagnosing headphone jack interference on new laptop - Page 1
Forum section: electronics / projects

author: TheBorg
author_rank: Frequent Contributor
timestamp: August 02, 2015, 07:32:27 am
content: Long story short, I got a new laptop to replace my long-aged MacBook. I got a Thinkpad Yoga from Lenovo which is just about perfect for me - with one minor problem: the headphone jack. For some odd reason, there is always a high pitched squeal that can be heard using headphones - especially on the right side. As I tend to listen with headphones a lot, this can get quite irritating after a while. The problem manifests itself worst when the laptop is actively charging which makes me think it is some kind of interference from the charging circuitry at work. If possible I would like to eliminate this squeal, and just wanted to ask a few questions and get your advice.I haven't taken apart the computer yet, but there are a couple pictures of the motherboard out there. Inthispicture it shows the battery cabling going over part of the PCB that leads to the headphone jack (far right). I found aneBay listingwith photos of the flip side of a similar PC, which show traces going to the headphone jack that pass under the battery cables.So my first question is - is it possible that the current going in and out of the battery can cause this type of interference? Or is it more likely to be the charging circuitry itself?Secondly, if I were to put some insulated copper sheeting between the battery cables and the PCB (if that is likely the issue), could that cause potential issues down the road? I don't know how EMI would react in this situation.Thanks so much for your help! It's a long shot, but hopefully there is something I can do to fix this problem...

author: picandmix
author_rank: Frequent Contributor
timestamp: August 02, 2015, 08:32:54 am
content: Assume you have tried different headphones to prove its not them.Otherwise, assume you have similar consumer right to us, if its faulty take or send it back for repair, replacement or your money back.The moment you start doing any mods or taking it apart you risk invalidating any warranty.

author: rollatorwieltje
author_rank: Unknown
timestamp: August 02, 2015, 09:42:29 am
content: First check if it isn't one of the typical Realtek audio issues (afaik the Yoga has a Realtek chip). One issue is that it (sometimes?) enables the microphone when you plug a headphone in, the other issue is noise when the chip goes into standby.

author: DanielS
author_rank: Frequent Contributor
timestamp: August 02, 2015, 11:32:18 am
content: If the board was not carefully laid out, it is possible that the audio chip ended up somewhere along a high current ground path and the noise you are hearing comes from the noise voltage generated by that current across the audio circuitry. If that is the case, then any replacements you get will likely have the same issue.

author: German_EE
author_rank: Super Contributor
timestamp: August 02, 2015, 12:09:58 pm
content: It's a new laptop, take it back to your Lenovo dealer and ask for a replacement.

author: fluxcapacitor
author_rank: Frequent Contributor
timestamp: August 02, 2015, 12:26:15 pm
content: The fix seems to be rolling back the driver .https://forums.lenovo.com/t5/Lenovo-Edge-Yoga-LaVie-Z-Flex/Yoga-3-Pro-Speaker-stopped-working-headset-jack-still-works/td-p/2031945/page/2

author: TheBorg
author_rank: Frequent Contributor
timestamp: August 04, 2015, 06:18:31 am
content: Sorry for the delay...I've tried multiple pairs of headphones and the problem occurs on all of them, so it's definitely the computer.I got one model that had the same issue and promptly returned it, but seeing as how this one has the same issue and others have reported it, I think it's either a hardware or software issue with the laptop itself.I'll try rolling back the driver, thanks!

author: TheBorg
author_rank: Frequent Contributor
timestamp: August 08, 2015, 05:20:35 pm
content: No rollback option in my drivers, so I updated it to the newest one on Lenovo's page (07/15). Still has the problem, I'm guessing it's hardware at this point? Any harm in putting some tape in there as long as it is insulated? I highly doubt that it would actually do anything, but it's worth a shot, right?

author: Richard Crowley
author_rank: Super Contributor
timestamp: August 08, 2015, 06:04:36 pm
content: I am using my Lenovo Yoga 13 which is very nice, and fortunately the headphone output is as "clean" as any computer I have ever had. But no analog audio input or output to a computer is going to be as good as your average audio gear.From the description of the symptoms, the problem sounds congenital and endemic to the design of the hardware. IMHO, it wouldn't be worth the trouble (and the RISK) of trying to remedy the problem internally. The smaller these things get, the less space there is, either for the original designers, or for an after-market hack to add power bus filtering and/or Faraday shielding, etc.If everything else is good with the computer, it may be worth trying an external USB audio interface. There are some as small as a thumb drive and have headphone and microphone jacks. Getting the audio OUTSIDE the computer case is one of the primary ways of defeating this kind of "digital hash".