Vizio E421VO intermittently won't power on

[MisterD]

Powers on normally sometimes and other times will not power on and Vizio light stays amber, could this be a bad EEPROM? Can the EEPROM be intermittent?

[MisterD]

Re: Vizio E421VO intermittently won't power on

I haven't even taken the back off yet, a friends TV, he said it will not power on at times, maybe it's his remote control, not sure he didn't bring it with the tv, anyway I have shut it off and powered it back on about 30 times, comes right on everytime.

[MisterD]

Re: Vizio E421VO intermittently won't power on

I found one ebay seller (tv repair shop) selling EEPROM chip that says a bad EEPROM can have an intermittent problem of the tv failing to power on and the logo light stays amber, I myself have only seen a completely failed EEPROM.
I'm not getting any replies here so I assume that no one else has seen the intermittent EEPROM.
He is going to just take the TV back home and try it again since I found the mounting/ground screws were not completely tightened down on both the power supply and main board.
Of course I tightened them down.

[MisterD]

Re: Vizio E421VO intermittently won't power on

It worked for a little while, he has other TV'S so he just waited awhile then brought it back to me today, At first it powered on normally, I left it on about 2 hours and was able to power off/on with normal operation.
Then it finally failed, powers on but frozen on screen Vizio Logo, must be unplugged to power off, so it is most likely that the EEPROM needs replaced to fix the problem. I will most likely order one from ShopJimmy.

[SLK001]

Re: Vizio E421VO intermittently won't power on

Do you have the capability to read the supposedly bad EEPROM so that it can be compared to a known good EEPROM? Maybe do a FACTORY RESET first, if you can get the set to stay on long enough.

[MisterD]

Re: Vizio E421VO intermittently won't power on

No, I do not have any way to read the bad eeprom, I did not plug it in to AC all night, I plugged in and powered on this morning and still have the frozen on screen Vizio logo.

Can't do anything in this state except unplug it.

[budm]

Re: Vizio E421VO intermittently won't power on

http://www.shopjimmy.com/catalogsear...q=Vizio+E421VO

He has EEPROM and also main board repair kit.

[MisterD]

Re: Vizio E421VO intermittently won't power on

Thanks Bud, I ordered the EEPROM from shopJimmy, I've only replaced one on a 32 inch Element, I cut that one off using a razor blade and removed one leg at a time, one trace lifted but didn't detach from the board so it was a sucessful repair on that one.
How do you do them when you replace the EEPROM?

[budm]

Re: Vizio E421VO intermittently won't power on

I use flux and flood the legs with added solder using 60W iron with wide tip.
Cut the legs off first is also another way to do it.

[MisterD]

Re: Vizio E421VO intermittently won't power on

I was wondering if I could carefully cut the legs but then leave them soldered to the mainboard then set the new EEPROM right on top of the old legs and solder the new one legs to legs, maybe cut the legs a little shorter on the new one.

[dick_barton]

Re: Vizio E421VO intermittently won't power on

Flooding the chip with solder is easy. Solder all the legs together both sides and run the iron around the chip. Then just clean up the remaining solder with solder braid. The hint to carefully cut off the legs with a sharp knife and then remove the legs which remain one at a time proved really useful the other day when I did it for the first time.

If it's an 8 pin device flooding with solder is dead easy.

Edit
I would never solder a replacement IC over the existing legs of the old IC which has been cut off

[MisterD]

Re: Vizio E421VO intermittently won't power on

It's an 8 pin device, I will possibly try flooding the legs with solder using flux. I have watched a couple YouTube videos where it was done that way. Thanks for the advice.

[SLK001]

Re: Vizio E421VO intermittently won't power on

Flooding the pins with 63/37 solder also helps lower the melting temp of the Pb-Free crap. Also, with all the pins flooded, a heat gun could be used to remove the device intact. Use aluminum foil held down with kapton tape to surround the chip, which will protect the other parts from too much heat.

[MisterD]

Re: Vizio E421VO intermittently won't power on

I went ahead and removed the chip today by using a generous amount of flux, flooded it with a 25 watt pencil iron and 60/40 solder on both sides going back and forth from one side to the other just a couple of times then slid it off to a clean area ( no smd's ) on pc board. Worked out very well.
Now I'm waiting on the replacement EEPROM to arrive. Thanks again.

[MisterD]

Re: Vizio E421VO intermittently won't power on

The pc board has a white dot to show where pin 1 (dot on chip) goes to ensure correct placement.

[MisterD]

Re: Vizio E421VO intermittently won't power on

Received EEPROM Chip from Shopjimmy this morning, carefully soldered it in place with low wattage pencil tip iron.

TV now works as it should. :-)

[dick_barton]

Re: Vizio E421VO intermittently won't power on

Well done. Fingers crossed.