How to test for a bad EEPROM on a vizio

It's not going to be the tcon board, it's either the main or power board, pull the back off and test the PS_ON pin on the power board to see if your loosing the command for power supply enable (3.3VDC) if so replace the main, if it stays then the power supply. Chances are it's your EEPROM that's bad causing the issue your having

I'd look at the EEPROM as having bad information, either replace the IC if you can or the entire main board, this has been a common issue for this model Vizio set

You may try, by the part number, they should be the same board with a efferent EEPROM firmware version.

EEPROMs won't have no match. You should use the exact number. The loaded software cannot be changed; you know.

Eeprom for Vizio VL420M Main Board 3642 0682 0150 U14 EPROM ONLY


soldered in part

Answered.

The power supply get's it "turn on" signal from the main board. It is very likely you have a faulty main board. Do you have electronics experience??

I had this problem and did some troubleshooting. Bought a programmed EEPROM from a place called Ernesto's and swapped out. Fixed! The EEPROM in this set is known to become corrupted.

116-324: Controller Error (Illegal Exception)

To access Service Mode, press Up and Down Arrows at power ON.
Go to EEPROM Test

EEPROM Test
? Start
? Processing
? Check OK
Performs write/read/verification of the test patterns (0xff, 0xaa, 0x55, and 0x00) on one byte at every 0x400 from the first address of EEPROM.

- The service mode functions are same as those of the previous models.
1) Test pattern 1: Service test print pattern 1 will be printed.
2) Test pattern 2: Service test print pattern 2 will be printed.
3) Test pattern 3: Service test print pattern 3 will be printed.
4) Cleaning at the service test print: Check the Cleaning box and perform the service test print.
Cleaning will be performed before the service test print is printed.
5) EEPROM initialization at the service test print: Check the EEPROM Clear box and perform the
service test print. EEPROM will be initialized.
6) Destination setting: Select the device ID to set the destination.
7) Ink absorber counter resetting (Main): Main ink absorber counter will be cleared.
8) Ink absorber counter resetting (Platen): Platen ink absorber counter will be cleared.
9) Device ID acquisition: Device ID will be displayed on the PC.
10) EEPROM information acquisition (Dump): EEPROM information will be displayed on the PC with
the HEX dump.
11) EEPROM information acquisition: EEPROM information will be displayed on the PC.
12) Nozzle check pattern print: Nozzle check patter will be printed.
13) Cleaning A: Cleaning A will be performed.
14) Cleaning B: Cleaning B will be performed.
15) Cleaning C: Cleaning C will be performed.
16) Cleaning D: Cleaning D will be performed.