Sunday, March 26, 2017

Python 3: ImportError: no module named win32api

I'm using Python 3.5 (32-bit) with pywin32 installed. I was trying to import win32com.client. but I was getting ImportError: no module named win32api

Solution:
As TulkinRB mentioned here, it seems like a bug with the module. I was able to fix it by editing Python35\Lib\site-packages\win32com\__init__.py, and replace import win32api with from win32 import win32api.

Ref:
pywin32 - Python 3.4 :ImportError: no module named win32api - Stack Overflow

Wednesday, March 15, 2017

Wireshark: How to extract files from a .pcap file

If you have a packet capture that contains data such as images and zip files, you can extract them using Wireshark.

1. open the .pcap file in Wireshark
2. go to File -> Export Objects -> HTTP...
3. a file list would pop-up and you can save the desired files

Monday, January 2, 2017

Firebase: Connect custom domain for Firebase Hosting

I was getting the message "Unexpected TXT records found. Continuing to watch for changes." as Firebase tries to verify my domain ownership.

Depends on your domain registrar, you may need to set the TXT records with host "@" instead of the actual host name as provided in the instruction. It solved the issue with my registrar (namecheap).

Ref:
firebase - Adding custom hosting domain: "Unexpected TXT records found. Continuing to watch for changes." - Stack Overflow

Sunday, January 1, 2017

CSS3: Make div 100% height of browser window

The viewport-percentage lengths are relative to the size of the initial containing block. When the height or width of the initial containing block is changed, they are scaled accordingly.

These units are vh (viewport height), vw (viewport width), vmin (viewport minimum length) and vmax (viewport maximum length).

example:
div {
    height:100vh;
}


Ref:
html - Make div 100% height of browser window - Stack Overflow

Thursday, December 29, 2016

Outlook: There are more items in this folder on the server

I noticed some of my older emails (more than 1 year old) do not show up by default. I need click on the link at the bottom in order to see them.

It turns out to be related to the Mail to keep offline setting.

I just changed mine to "All".

Ref:
Only a subset of your Exchange mailbox items are synchronized in Outlook 2016 or 2013

Monday, December 26, 2016

TouchPad: Scroll icon stuck on screen

Recently I'm using a HP Elitebook 820 G3, running Windows 7. It has a TouchPad with a scrolling feature. Unfortunately, from time to time, the scroll icon would get stuck on screen. Even worse, you may end up with not just one, but multiple scroll icons stuck on screen.

Solution:
Thanks to MrJGR who shared a way to disable the scroll icon all together.
1. Open regedit
2. Navigate to HKLM\SOFTWARE\Synaptics\SynTPEnh
3. Right-click and create a new DWORD (32-bit) Value, with name "UseScrollCursor"
4. Reboot the computer

Ref:
TouchPad Scroll Icon Stuck on Screen after Windows 10 Upgrade - Microsoft Community

Sunday, December 18, 2016

Navien tankless water heater: Error code 38

My Navien tankless water heater (model 240A) stopped working all the sudden. After opening the cover, I found code 38E displayed on the control board. However, this error code was not found in the operation manual.

According to Navien's FAQs:
"I have no error codes on my remote, yet my unit will not produce hot water. What should I do?

The issue is most likely the flow sensor inside the unit is not spinning properly.

We recommend opening and closing the pressure relief valve (should be located near the outlet of the unit). Depending on amount of debris affecting the flow sensor, this may help temporary. We recommend contacted your original installer or an NSS to service the sensor."

I also found this 38 error code listed here mentions checking the water flow sensor. Based on various forum discussions, it seems to be the root cause for others who experienced the same error as well.

Solution:
Luckily, it is not too difficult to take it apart and check the water flow sensor. Thanks to youtuber Tredsaw12 who created this step-by-step guide, I was able to extract the water flow sensor. If this is your first time working with the water heater, I would suggest you first check this video by Skobel Homes to get a better understanding of it.

After taking out the sensor, try shaking it. You should hear some noise as there's a small gear inside. If not, it's probably stuck which caused the failure. Check if there's any blockage inside and clean it. Try running water through it. Also try blowing air through it with your mouth. You should feel the gear inside is spinning.

And then, you just need to reverse the process and put it back together. Hopefully your water heater will start working again. If not, you may need to replace the water flow sensor and/or call a professional for further inspection. Good luck!

Ref:
Navien Tankless Error Codes
FAQ | Navien
SIMPLE - Navien tankless FLOW SENSOR replacement -- 10 minute job - YouTube
How to maintain your tankless hot water heater - YouTube