EEPROM

EEPROM stands for Electrical Erasable Programmable Read Only Memory. As the name recommend, an EEPROM can be both erased & programmed with electrical pulses. Since it can be both electrically written in to & electrically erased, the EEPROM can be quickly programmed & erased in circuit for reprogramming without removing them from the circuit board.

EEPROM is also called a non-volatile memory because when power is turned off the stored knowledge in the EEPROM won't be erased or intact. New EEPROM have no knowledge in it & usually must program with a programmer before it can be use. Knowledge stored in this type of memory can be retained for plenty of years without a steady power supply.

What is the function of EEPROM? EEPROMs are used to store user programmable knowledge such as: -

o VCR programming knowledge

o CD programming knowledge

o Digital satellite receiver control knowledge

o User knowledge on various consumer products

EEPROM in monitor performs functions:

o When a monitor is switch on it will copies all knowledge or knowledge from the EEPROM to the microprocessor. For example, the EEPROM will let the microprocessor know the frequencies at which the monitor is going to operate.

o The EEPROM is used to store the current settings of the monitor. The settings of the monitor won't be erased even when the monitor is turned off. Anytime a adjust is made in the monitor settings, the microprocessor updates the setting in the EEPROM. When the monitor is turn on again, the stored settings are used to set up the monitor for operation.

What are the signs if the MONITOR or TV's EEPROM knowledge is corrupted or damaged?

o No high voltage (no display).

o Horizontal or vertical frequencies run.

o Cannot save (store) current setting.

o Definite control functions like sound, brightness & contrast control does not functioning.

o On Screen Display (OSD) does not function or the OSD have a corrupted display.

o High voltage shutdown (EEPROM set the horizontal frequency way low or times the line frequency perhaps leading to failure of the horizontal output transistor (HOT)).

What is an EEPROM programmer or copier?

EEPROM seldom fail, they lose or have their memory (knowledge) corrupted may be due to high voltage & static discharge from a monitor. times reprogrammed they are as lovely as new. As mentioned earlier, new EEPROMs are blank & require knowledge or knowledge to be loaded in order for it to functions. The job of copying the knowledge in to an EEPROM is done by a programmer or a copier. Programmers come in all shapes & sizes. You can copy these devices for repair replacement only. You cannot copy them for resale without a letter of approved from the seller who produced them. There are a few companies selling EEPROM programmer:

Typical EEPROM part no:

24C02, 24C04, 24C08 etc

24C325, 24C645AT17C65, AT17C128 etc

93C06, 93C46, 93C56, 93C66 etc

25010, 25020, 25040 etc