The problem with unit, Sharp Primo model 14v-r70m, was that okay in standby mode but breaking the fuse when trying to turn it on.
Action taken:
Have check the components in the power section and hang up the connection of the secondary supply going to the flyback transformer and have already replaced the IC regulator whose value was STRW5453A.
Actual Defected parts:
After checking all the components, I try to pull out the Posistor and... [ Continue reading... ]
The output voltage of this charger is approximately 2.49V-2.5V in the pin1 of TL431 but if it reaches to 9.2V (full charge of 9V battery)the voltage on positive(+) of battery that will starts the TL431 and it will light up the FULL indicator led which is the Green LED.
parts list:
B1 - battery snap
DC socket
R1 - 500 ohms
R2 - 75 ohms
R3 - 4.7k ohms
R4 - 500 ohms
C1 - 10uf 25V
D1 - LED red
D2 - 1N4004
D3 - 1N5242B
D4 - 1N5235B
D5 -... [ Continue reading... ]
This is an example how an LCD start up circuit looks like. This is only a very simple example and other start up circuit may looks more complicated than this one. We can make this image as a guide to give us an idea on how do a start up circuit of an LCD may looks like and how do it... [ Continue reading... ]
This is a very easy to build EEPROM Programmer used to reprogram the corrupted data on a Memory IC of a television set. This device is very useful for us technicians to easily put program to a newly brought Memory IC which is blank and we need to programmed it using a data we extract from a known Television.Credits to Sir Pete of Elab for contributing the device he used when reprogramming a Memory IC.
Schematic... [ Continue reading... ]
In this article, we will learn how to Bypass LCD TV Inverter of Backlight with a Shutdown Problem. But a reminder, do it with a caution so don't let your LCD TV for too long. Just click the image to read the full articles about Bypass LCD TV Inverter of Backlight. As mention of one of the commenter in that site, Eklunge share some of his experience regarding in this problem:
This faulty was mostly caused by the protection... [ Continue reading... ]
Today I will share to you the Blinking Codes of Sony Television that I have read in a forum originally posted by Rigor37 of at Electronicslab Forum. I think this article is very important for us repairer to serve us a guide when we encounter a blinking error when we are repairing a Sony Television. Below is the post originally posted in the forum.
More of the latest model of Sony TV's have a built in Self- Diagnosis function. If the... [ Continue reading... ]
This is an updated version of Digital Frequency Display. This version features a much simpler front end, an extended frequency range and a coarse calibration function implemented in software.
It retains the ability to add or subtract one of three IF offsets, making it suitable as a frequency display for a direct conversion or superhet receiver (also for transmitters using "on frequency" VFOs or using mixing).... [ Continue reading... ]
In this article, it is about repairing a LG Monitor with a Blurred Picture Problem. It was the complain on one of the computer user in one of the offices where I am working as a computer technician.
Problem:
Blurred picture after one hour of usage but if you adjust the focus and screen control on the flyback, the picture goes to normal but after three minutes, it came back to its original problem which is blurred... [ Continue reading... ]
This is a post on a forum that I found while searching for the fix of a laptop problem of not booting up. I have done to attached an external monitor to be sure if it really not booting and not black screen problem that is usually caused by a damaged Backlight or Inverter circuit of the screen.Here is a post that is originally posted on http://en.kioskea.net which is a forum site that discuss this kind of problem. This is a quote from... [ Continue reading... ]
In this video, its showing how to control a Stepper Motor With a Forward-Reverse and Speed Control Function. The circuit used is very simple using a 555 timer IC and a 74LS74 dual flip-flop and other components. The transistors used to drive the stepper motor are BD131 which should drive about 1.5 amps per winding. Just click the link of the Video to bring you on youtube to see more info about this video including the diagram of the... [ Continue reading... ]
