Wikipedia:Reference desk/Archives/Computing/2020 April 3

= April 3 =

Explain mobile phones
If I buy a mobile phone is there a service I need to subscribe to and pay for to get the thing to work? Also, how does one get a mobile phone working once one has one, and how is one assigned a number to use with the phone? Apologize if that's several questions at once, but this is all worth knowing. Freeknowledgecreator (talk) 10:34, 3 April 2020 (UTC)


 * If new, the phone will come with simple instructions on how to get connected. You might want to read prepaid mobile phone and mobile phone for more information.--Shantavira|feed me 12:15, 3 April 2020 (UTC)


 * You may need a subscription with a mobile network operator that maintains a local cellular network, such as Spark or Vodafone. Usually there is a confusing range of options referred to as "plans"; as a beginner it is probably best to start with the most basic one, unless you already know you will use it for streaming Netflix all day. Your network operator should be able to assist you, but be aware they have an incentive to sell you a plan that is more expensive than you need. Payment options differ between network operators, but if you have a credit card you'll probably be able to pay directly with your phone, following the instructions provided by the network operator. --Lambiam 15:06, 3 April 2020 (UTC)
 * a) If you want to use it as a mobile phone you need to use someone's mobile phone network, which usually involves paying them to use it. This includes if you want "data", which actually just means "the Internet over a mobile phone network". If you're low-income there might be free/subsidized options available. "Work" is a very broad word; modern phones generally have at least Wi-Fi and do stuff even without a cellular connection. (In other words you don't have to pay just to be able to power on the phone). Mobile phones are just computers in a certain form factor, even though lots don't appreciate this because "computer" means to the general public a thing sitting on a desk.
 * b) Turn it on and follow the directions. To set things up with the mobile network operator there's generally some "activation" procedure you have to follow. When you sign up with them they give you directions for this. The operator assigns you a phone number. In lots of countries you can transfer an existing phone number as well (even landline numbers sometimes), which, again, involves following their procedure for doing this. --47.146.63.87 (talk) 21:04, 3 April 2020 (UTC)
 * To encourage keeping discussion in one section I'll answer here. SIM card is a pretty jargony article so I'll just give the in-a-nutshell answer. It's an ID card for your phone. It identifies it to the mobile phone network. This is the only way the network knows whose phone is whose; all the network base stations "see" is a bunch of data that the antennas receive. Modern phones have a slot you put the SIM into (some have multiple slots). You typically get a SIM card from your mobile network provider. They're designed to be cheap and disposable. (Some providers can also use a SIM card you already have.) Just sign up and you'll find out whether they send you one or whatever. This is not a thing you need to worry about ahead of time. --47.146.63.87 (talk) 02:50, 4 April 2020 (UTC)

Audio problem
Hi

I am running a PC with Win 7 and either Firefox or Chrome. I am trying to watch a lecture on how to play bridge and it has gone silent. If I play episode 1 or 2 from that youtube channel, I get sound. When I play episode 3 I get no sound. The video is NOT muted. The audio stuff all works fine - I can hear the OTHER videos nicely. I was able to hear episode 3 ok until about 4 minutes into it - I had been pressing play and pause a lot and altering the time on the slider to rehear bits of it.

It is interesting that the same problem occurs on Firefox (where I started) and on Chrome and that both "know" how far through the video I am. They both start wherever I left off last time, in this strange silent mode. If I look at the Audio Mixer from the toolbar, both Firefox and Speakers show a green volume bar wobbling up and down - yet nothing emerges from the speakers. I have tried rebooting the PC and the problem survived the reboot (including remembering where in the video I had got to).

Other people are able to hear it ok on their computers.

I am completely confused. Any ideas anyone? -- SGBailey (talk) 20:11, 3 April 2020 (UTC)
 * First suggestion: try it in a "private" browser window. (Both Firefox and Chrome have this feature.) Why I'm suggesting this: you're using "regular" browsing mode and YouTube is storing its cookies, which is how it remembers your position in the video. So we're seeing whether that has something to do with it. --47.146.63.87 (talk) 21:12, 3 April 2020 (UTC)
 * Sorry, but I sincerely doubt that YouTube stores time positions of videos in cookie data. That would be very inefficient to update every time something changed. No, they store it in our account data, hidden fields somewhere that may or may not be accessible through the "Takeout" feature. I just checked my cookies and there aren't eight dozen time positions stored there. Sorry. However, your suggestion to try it in "Incognito" mode is a good one, it may eliminate some variables, such as browser extensions that are interfering. I would say, disable browser extensions entirely, re-enable one-by-one if the sound works, see if any of them have broken the sound. Elizium23 (talk) 21:35, 3 April 2020 (UTC)
 * The problem persists in a private window. -- SGBailey (talk) 21:57, 3 April 2020 (UTC)
 * I also tried watching the video having logged out of youtube as a guest. Same problem. Is there a way of clearing the youtube cache, cos it appears to know about that particular video. -- SGBailey (talk) 22:01, 3 April 2020 (UTC)
 * YouTube (and many sites) track who you are with cookies, and do this even if you're not logged into an account. They can store things like where you left off watching a video on their end. But now we know it's not that. --47.146.63.87 (talk) 02:30, 4 April 2020 (UTC)
 * Next thing to try: can you without much hassle try watching the video on another device? Mobile phone, tablet, laptop, TV, etc. etc.? If there's no issue there we know the problem is limited to that computer. As you seem to think as well, it might have something to do with your computer caching a corrupted copy of the video. --47.146.63.87 (talk) 02:30, 4 April 2020 (UTC)
 * No problems ATM on my (Win 10) laptop. It is just this one video on this one computer. -- SGBailey (talk) 06:26, 4 April 2020 (UTC)
 * You could right-click the image and select "Troubleshoot playback issue" that would send feedback to Google, if perhaps the problem is on their side? Elizium23 (talk) 06:54, 4 April 2020 (UTC)

I've watched it on my laptop now. I think I'll wait a week or two then try again and see if the presumably corrupt file gets itself flushed from some cache somewhere on my PC. Thank you all. -- SGBailey (talk) 12:33, 4 April 2020 (UTC)
 * You can try clearing the caches for both browsers (do a Web search for directions), but the odd thing to me is it affects both browsers, which use separate caches. I don't know if Windows is doing some weird stuff behind-the-scenes. --47.146.63.87 (talk) 00:24, 5 April 2020 (UTC)

Explain SIM cards
Someone please explain to me what SIM cards are, how one would use them with a mobile phone, and why one would want to do this. Freeknowledgecreator (talk) 23:59, 3 April 2020 (UTC)
 * Have you read our article on them? They are not an optional part of mobile phones, unless you plan to stay off the networks. Elizium23 (talk) 00:14, 4 April 2020 (UTC)
 * Don't take this personally but you're allowed to post another question in a section. Please do that in the future instead of starting a bunch of separate sections. --47.146.63.87 (talk) 02:25, 4 April 2020 (UTC)
 * SIM card 2601:648:8202:96B0:E0CB:579B:1F5:84ED (talk) 04:23, 4 April 2020 (UTC)


 * Your phone company will give you one. It has to be inserted into a slot in your phone before you can make phone calls or access the internet.
 * If you buy your phone straight from the phone company, they'll usually install it for you. ApLundell (talk) 04:49, 4 April 2020 (UTC)
 * Let's qualify that a bit: if a phone has the capability to make calls over WiFi then you don't need a SIM card to use the phone in many situations. But yes, to use the cellular network, the SIM card is necessary. Elizium23 (talk) 05:17, 4 April 2020 (UTC)

"They are not an optional part of mobile phones". Fine. It's just that one can buy them separately from mobile phones, and it's not exactly clear when you're buying these things online that a SIM card is actually necessary and not an optional extra. Thanks. These responses are helpful. Freeknowledgecreator (talk) 06:25, 4 April 2020 (UTC)
 * In very brief summary, the SIM (subscriber identification module) tells your phone which network to use. The unique IMSI code on it (as opposed to the IMEI code which identifies the device), lets the network determine who your are, which phone number is allocated to the SIM, and your contract details. It is a required part of the European GSM standard, and was optional in the American CDMA standard. If you change network, you need a new SIM. If you want to change your phone handset then you just transfer the SIM from the old phone to the new one (there's a few limitations, but in general the principle works). A change to the contract or phone number can be done without changing the SIM. LongHairedFop (talk) 11:24, 4 April 2020 (UTC)


 * Some phones and networks use sim cards but not all do. Traditionally GSM networks used them while other networks didn't.  Now they are more widespread across networks.  21:40, 4 April 2020 (UTC)  — Preceding unsigned comment added by 2601:648:8202:96B0:E0CB:579B:1F5:84ED (talk)
 * All deployed 4G networks use SIM cards, as far as I'm aware, and someone buying a phone today, even used, will want 4G service unless they're in a quite impoverished country, so I felt it was not necessary to go into this topic. In particular, there is a risk of confusing the questioner. --47.146.63.87 (talk) 23:21, 4 April 2020 (UTC)
 * This is intended as a reply to ApLundell's comment but given the outdent above I can't reply inline: I'm pretty sure that depends a lot on the country. I don't think it's the norm in NZ (where I believe the OP comes from), and probably Malaysia. If you buy it at a store, they may help you install the SIM if you want. But I'm fairly sure it's common that they just provide a SIM pack if anything. {{paragraph break{{Even that isn't always the case since it complicates prepaid vs post paid, as well as the fact many people want to keep their existing account (be it prepaid or post paid) and while these can be transferred between SIMs that adds unnecessary work compared to just changing SIM. More commonly the SIM may be free if you want one at least for a new account, but provided separately. (I mean not in the same shrink wrap. If you make an online order you'll likely get them both delivered in the same package.) {{paragraph break}} Note that it's quite common people prefer their stuff to come shrink wrapped and unopened, to reduce the chance of being sent a refurbished/returned phone so although they could open it open and put the SIM in they will normally only do this in front of you. (For parallel imported products, it's more complicated given the likely need to replace the charger and maybe other things.) {{paragraph break}} Anecdotally, my current phone is a Huawei P30 and the SIM did come separately, although there was a sticker stock onto the shrink wrap with a special code from the network provider (2degrees) for a bonus. Actually, as it was a pre-order and I signed up for a new postpaid account to get their discount offer, I received the SIM (when preordering) and cancelled the account (well converted it to prepaid, but I could have completely cancelled it within days) which was a while time before I received the phone. {{paragraph break}}Nil Einne (talk) 07:29, 5 April 2020 (UTC)