TRUNK dalam Telekomunikasi

Virtual LAN

Virtual LAN (VLAN) memberikan suatu metoda yang sangat flexible untuk memanage segment-2 jaringan menggunakan Switch LAN. Jika menggunakan VLAN dalam jaringan-jaringan yang mempunyai Swithes yang saling terhubung, VLAN trunking antar switches diperlukan.
VLAN memberikan suatu flexibilitas managemen dalam membuat Virtual LAN terpisah menjadi segment-segment atau subnet-subnet yang bisa dignakan untuk mendifinisikan lokasi terpisah atau jaringan-jaringan departemental. Penggunaan Virtual LAN dalam suatu jaringan LAN adalah bersifat opsional dan biasanya dipengaruhi oleh kebutuhan2 tertentu yang khusus seperti misalnya alasan keamanan dan pemisahan departemen.

Optical Mouse Cam

OK, so I finally decided to get my hands on the Arduino platform and see what all the buzz is really about. And I must say, I'm impressed. This is by far the most developer-friendly development platform I've ever seen. It's main advantages :
  • It's simple. The hardware is very simple and uses standard, commonly available components. The software IDE is basic but functional : editor window, status window, integrated serial terminal. That's it.

HDD Grinder Stone

In some www I found image of HDD transformed to grinding stone. It was placed in “jokes” category. But I decided, that small grinding machine is useful for hobbyist. I use old 2G HDD “Western Digital Caviar 22500″. It is only 5K rev/minute HDD. Removed cover and all heads, magnets. Took sandpaper and glued to one disk plate.

UTP Lighting Protection

How to test LCD screen inverter in a laptop

In this post I explain how I test the LCD screen inverter board in a laptop computer.
The screen inverter failure is very similar to the backlight lamp failure. In both cases the screen gets very dark and the image on the screen becomes very faint, barely visible under a bright light.
If you suspect the inverter board failure, I know only one reliable way to test that. It’s either replacing the inverter board with a known good one and see if it works, or connecting a known good backlight lamp and see if your presumably bad inverter lights it up.
In most cases I go with the second method – testing the laptop with a known good backlight lamp. Why? Because backlight lamps are pretty much universal. The same backlight lamp will work with many different inverters as long as they have matching connectors. I’ll talk about these connectors later.

Repair Mainboard

Step 1: Power button:
If there is power step 2, otherwise check power supply circuit , including: stand by 3v3 , chip SiO, Southbridge.

Standby 3V3:
- 5v standby voltage from ATX will lower down to 3v3 for the southbridge, often using an ic 1117 or 1084, 1085, 1086 (pin 3; input ATX STB 5V, pin 2; output 3v3 STB. The main life bulbs are not used IC which uses a circuit with few or MOSFET transistor to stabilize pressure.).

- Check 3V3 at A14 pin PCI slot (see picture).


Lesson 1


The FBT of the monitor has two potentiometers; the upper potentiometer adjusts the focus and the lower potentiometer adjusts the screen control. The screen control is a DC voltage which feeds the grid 2 of the CRT on monitors and also on TV sets. The higher the screen voltage, the higher is the brightness on the screen.

7.DARLINGTONTRANSISTOR                                                     8.TRANSISTOR