Apropos Tech Solutions Corp. Blog

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  • Hardware: monitor stuck on hdmi

    A seldom-used system gets started, and the monitor refuses to work. What might one do?

    The following is by my understanding.

    I mention in my post from June 30, 2026 about resurrecting an old computer from 2017 by loading Lubuntu Linux onto it. To my knowledge, the monitor it came with is of the same vintage.

    I went to start up said computer yesterday, but its monitor was unresponsive. It seemed stuck on HDMI mode but the computer is connected to it via VGA. Not knowing what to do, but busy, I left it until today.

    With the computer on, but the monitor unresponsively sleeping, I unplugged the monitor from the power bar, waited maybe a minute, then plugged it back in. The monitor immediately detected the VGA signal, and began displaying as appropriate.

    God knows what happens with system components sometimes, eh?

    Source:

    superuser.com (Jul 9, 2015). “Monitor stuck in HDMI mode.” https://superuser.com/questions/938476/monitor-stuck-in-hdmi-mode

    -js

  • Computer-constructs, accessories: writeable dvd for storage?

    Do people still use writeable dvds? There might be some situations where they’re an interesting option.

    The following is by my understanding.

    For storing media up to around 4gb, writeable dvds might be an option to consider.

    Some desktop computers still come with dvd read/write devices. Moreover, it seems peripheral ones can be bought for around 50CDN. Then, dvd-r discs can be found for less than one dollar CDN per unit. I’m referring to single-layer, 4.7GB ones.

    In my experience, usb drives 16gb or less are getting harder to find. So, for small jobs, especially 4gb or less, a writeable dvd might be feasible.

    Interesting, eh?

    -js

  • Accessories: charging issues: power bank won’t work with my phone?

    Fear that a power bank was malfunctioning evolved to realization about a particular phone.

    I paid 168 CDN for my current smartphone. I’ve had it for a year and loved it ever since I got it. It’s a big chunky phone with lots of battery and charges fully in about an hour.

    Yesterday my phone was just about dead, so I decided to charge it from the laptop power bank (see my post from Aug 14, 2026 about that evolving situation).

    I’ve tested the laptop power bank, both charging to it and recharging other devices from it, with success. However, experience tells me that sometimes more testing can be even better. I plugged my phone into the charging bank, usb c to usb c. To my surprise, it wouldn’t charge! (Actually it kept flashing between around 10W and 0.1W, but it seemed the phone wasn’t happy.)

    I immediately suspected, first, something wrong with the cable. I tried numerous others, but the problem repeated each time. Next I became fearful of the power bank. However, I tested my son’s phone with it: his phone charged fine. I had to admit, confusedly, that my phone seems to be the problem in that scenario.

    The power bank isn’t for my phone anyway; it’s for my son’s devices. Moreover, my phone charges fine from a power brick at the wall, so no problem there. It was just a surprising situation.

    So, apparently, a laptop power bank can work fine with some devices but not with others. (Actually, it does work with my phone usb a to usb c. While stable, that rate is only about 2W.)

    Interesting, eh?

    -js

  • WordPress: what is a child theme?

    In WordPress, one hears a lot about child themes. What are they, and why are they important?

    The following is my understanding.

    I mention in my post from June 18 the idea of a theme in WordPress. That said, what is a child theme?

    Be advised, this is a practical explanation.

    A child theme is a folder that lives outside the theme it’s based on, which we will call the parent theme. The child theme contains changes one has made to the parent theme. Assuming the child theme has been produced correctly, then selected as the active theme, WordPress knows to load its parent theme, then apply the tweaks that it finds in the child theme.

    The child theme must include a stylesheet called style.css, which is a plain text file. Said style.css file must have a header that includes the lines Theme Name and Template, where its template is the parent theme.

    How style.css in the child theme gets loaded depends on the parent theme. Apparently, some parent themes load the child theme’s style.css file automatically. With others, the child theme folder will need a functions.php file containing a custom function that will load its style.css

    The reason a child theme is important is that themes commonly undergo updates, just like other software. Any customization done to the parent theme may be overwritten during an update. However, the update won’t overwrite the child theme.

    Source:

    WordPress Developer Resources. (Jan 26, 2024). Child Themes. https://developer.wordpress.org/themes/advanced-topics/child-themes/

    -js

  • Autos: change oil indicator light reset, Dodge Grand Caravan 2016

    When you change your own oil, the “change oil” indicator light might come on at an unexpected time. Why, and how to reset it?

    The following is by my understanding.

    About every six months, I change the oil for both vehicles in this household.

    A couple of days back, the “change oil” indicator light came on when my wife started the van (2016 Dodge Grand Caravan). I knew I’d changed its oil in early July, so wasn’t worried.

    With the 2016 Dodge Grand Caravan, the “change oil” indicator light comes on according to a cumulative measurement of duty. When you change the oil, the computer system can’t tell. It just continues monitoring how much work the car has done since its last reset, and eventually reminds you to change the oil.

    To reset the “change oil” indicator on said vehicle, one follows these instructions:

    1. Turn the ignition to on/run, but don’t start the vehicle.
    2. Within 10 seconds, press the accelerator pedal down, then let it return, three times.
    3. Turn the ignition to off.

    Source:

    2016 Grand Caravan User Guide

    -js

  • Autos: tire pressure and load, part 0

    Does tire pressure increase when you put more weight on the tire? There are conflicting ideas…

    I’ve been looking around the Internet. Some people suggest adding weight to a vehicle will increase its tire pressure; some say it won’t.

    I’m of the opinion that added weight won’t increase a vehicle’s tire pressure, by the following reasoning. At a fixed temperature, PV=k, that is, pressure multiplied by volume is constant for a confined gas.

    Given PV=k (assuming fixed temperature), the only way for pressure to increase is if volume decreases. Yet, it seems unlikely to me that a tire will shrink as more weight is put on it. The tire can bulge out the sides, for instance, to make up for a decrease in height.

    I plan to revisit this topic, but that’s my idea so far.

    Source:

    White, J.E. (1987). Physical Chemistry. Books for Professionals, Harcourt Brace Jovanovich.

    Grassroots Motorsports. (2018). “Tire Pressure: Hoist vs On the Ground.” https://grassrootsmotorsports.com/forum/grm/tire-pressure-hoist-vs-on-the-ground/3231/page1/

    -js

  • Accessories: charging cords, usb c to usb c, part 2

    Charging devices, usb c to usb c: 100W?

    The following is by my understanding.

    I mention usb c to usb c charging cords in my post from August 14. I realized I needed some heavy-duty charging cords that could handle 100 or 140W.

    I bought an extra 60W one (pretty standard, as I understand), then one rated at 100W, and another one rated at 240W.

    A day or so later, the opportunity came to try out the cords: what wattage would they actually deliver? Moreover, how would the devices respond to them?

    It turns out the laptop will only charge at around 45W via usb c, so a normal 60W cord will suffice to recharge it from the power bank. However, the power bank itself is rated to receive up to 140W via usb c for recharge, which the charging brick can deliver. Therefore, I connected each, at its appropriate usb c port, to an end of the 240W-rated usb c cord.

    Using that cord, the power bank would only accept 100W, not more.

    It seems any usb c device might have its own mind that decides what charging rate it will accept. I guess that’s to protect the device(s) involved.

    Source:

    Ask Leo! (Oct 23, 2025). “USB Charging and Cables Explained: Safe and Simple.” YouTube. https://www.youtube.com/watch?v=jD54dscsefw

    -js

  • Web: proxy and reverse proxy, part0

    One hears about proxy and reverse proxy in the context of web servers. What are they, and why are they used?

    The following is by my understanding.

    A forward proxy server, or just proxy server, is a middleman: a request comes to it from a client, then the proxy sends along said request to the site that can fulfill it. The fulfillment site then sends its response back to the proxy, which forwards the response to the client.

    In the case of the proxy server, the fulfillment site thinks it’s interacting with the proxy; it doesn’t know about the client on the other side. Hence, the proxy can offer anonymity to the client, although the proxy itself knows all.

    A reverse proxy server is similar to a proxy server, but the client in this case is the fulfillment site. A web surfer sends a request to, they think, the fulfillment site. However, the request arrives to the fulfillment site’s proxy. Said proxy decides whether to pass the request along, and if so, to which specific port of the fulfillment site’s architecture.

    The requester, aka the web surfer, doesn’t know their request was processed by the reverse proxy.

    To its sponsor, the reverse proxy offers filtration of the incoming web requests. It sends each request to its appropriate destination, perhaps eliminating the bogus or dangerous requests.

    Source:

    Cloudflare. (2026). “What is a reverse proxy? Proxy servers explained.” https://www.cloudflare.com/learning/cdn/glossary/reverse-proxy/

    -js

  • Accessories: charging cords, usb c to usb c

    Charging a device, a cord is often needed. What are some considerations about charging at a usb c port?

    The following is by my understanding.

    This post is connected to my post from August 11 about laptop power banks, etc.

    Herein, “cord” and “cable” are used interchangeably.

    The charging brick and laptop power bank arrived. Neither came with a cord. I plugged the charging brick to the wall. Then, I connected the charging brick to the laptop power bank via the usb c cord I use to charge my phone.

    The laptop power bank’s display lit up. It indicated charging happening at around 56W. Yet, the charging brick could deliver 140W, and the laptop power bank could also receive 140W.

    I’d read that a particular specification of charging cord is needed beyond 60W; here was proof. It seems that basic, standard usb c to usb c cable allows up to 3A. Caveat: some usb c to usb c cord may not be made to that standard, so won’t even accommodate 3.0A.

    So, the laptop power bank was charging fine at just under 60W, but the charging brick could deliver 140W, and the laptop power bank could accept 140W as well. The limitation seemed to be the cord: it just couldn’t handle past 60W.

    I went out yesterday, seeking usb c to c charging cords. Serious ones have ratings on the packaging, by Watts and/or Amps. I bought one rated at 100W and one rated at 240W, around ten dollars each. Then I bought a “normal” usb c to usb c cable, rated for 3A, 60W.

    I haven’t had a chance to try out the 100W or 140W cables because right now everything is charged. However, I plan to follow up when the opportunity arises:)

    Source:

    Cherchian, R. (Aug 2, 2025). “USB-C Cable Types Explained: Speed, Power, and Video Differences.” YouTube: https://www.youtube.com/watch?v=guegsQSZYD4&t=64s

    -js

  • Accessories: laptop power banks

    Some people need their computer battery to last longer between charges. A laptop power bank can be a solution.

    The following is by my understanding and research.

    As I’ve come to see it, a laptop power bank is a particular kind of charging bank. (See my post from Jun 6 about charging banks.) Being intended to charge a laptop instead of, or besides, a phone, the laptop power bank might typically have capacity between one and two times a laptop’s battery. Yet, laptop charging banks are typically are constrained to less than 100Wh because of airline restrictions.

    A working scenario might be like this: a laptop has battery capacity of 50Wh. The laptop power bank to replenish it might be 25000mAh, which translates to a 92.5Wh (see my post from Aug 3). From it, the user might get almost two additional use cycles on the laptop without having to plug into the wall.

    Then, at some other time, the laptop power bank itself will need to be replenished. To do so reasonably quickly, another accessory is needed, called a charging brick, which connects to a wall socket on one end and then to the laptop power bank on the other. Charging bricks are often not mentioned in the context of laptop power banks, but are inherent in the scenario. A fast charging brick may be able to fully recharge a laptop power bank in about an hour. The recharging is done by USB-C PD.

    Charging and recharging speeds of laptop power banks and charging bricks I intend to discuss in a future post.

    Laptop charging banks often have numerous ports, so that a laptop and a phone can be recharged simultaneously.

    Source:

    My Laptop Spares. (Mar 27, 2026). “How To Choose The Right Laptop Battery Capacity.” https://mylaptopspares.com/blogs/news/how-to-choose-the-right-laptop-battery-capacity?srsltid=AfmBOor5KdU74YcRPtfXPFNtuX9I5b_cqXkBydRwLHJ-GTx1USU0xs64

    ca.ecoflow.com

    -js