Comments on: No Display In TV Due To EEprom IC Fault

By: Davod Amirajam

Davod Amirajam — Mon, 18 Mar 2024 08:43:01 +0000

In reply to Christian Robert Adzic.

every eeprom have program erase time
not only in tv but in monitor and network card (keep mac adress),....

another reason to fail is heat up chip (this tv )also more than 10 years old

voltage ,crystal ,bad timing no .if you are doing this

bad eeprom and bad spi always happen

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By: Newton

Newton — Wed, 24 May 2023 16:22:24 +0000

In reply to beh.

Sony 20 inch IC TDA8844 the sound is ok but no pictures are coming plz explain some ic has been replaced but no change

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By: Reuben Sylvester

Reuben Sylvester — Tue, 18 Jan 2022 18:48:46 +0000

Hello Suranga, what a nice job. I have a quick doubt. I am using a Sony Wega Trinitron CRT TV, model No: kv-xj29m80. I want to make some adjustments but when I access the service menu, I am able to make the changes but cannot write the changes. When i attempt to do so, the whole screen becomes orange and returns to standby mode. When i switch on from standby mode, the settings are all gone. I am using the right remote and correct commands. Please advise what needs to be done. This is a factory set which has never been repaired. Regards.

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By: Emmanuel

Emmanuel — Fri, 01 Feb 2019 10:27:29 +0000

Hmmm! really educative and impactin, keep it on.

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By: Hakan

Hakan — Wed, 23 Jan 2019 19:29:28 +0000

Where did you find unfaulty eeprom content to reprogram?

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By: beh

beh — Thu, 17 Jan 2019 02:45:39 +0000

WELL DONE SURANGA.

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By: Christian Robert Adzic

Christian Robert Adzic — Wed, 16 Jan 2019 23:58:14 +0000

Hi!
I really appreciate your repairing, good job done and another tool saved.
I have several questions or I'm maybe a bit confused.
I would like to dig a bit deeper in this situation.
So, you was found an eeprom with a corrupted data.
Ok, that makes sense to have an irregular setup for the unit.
You solved the problem by changing the old eeprom with a new empty eeprom.
The cpu should recognize the empty eeprom and fill it with the values of the new setup.
This is the point where the repairing was successfully done.
so, you had a corrupted eeprom content but not a bad eeprom ic itself on the hardware level.

From my point of view, I have several questions:
Why you not tried to r/w the old eeprom?
With a r/w you could get the data from the eeprom, even if the eeprom was corrupted, but that is not the main point of the r/w I'm requested.
You could erase the content of the eeprom and you would have a blank eeprom as the new one and you would also repair the unit, without to use a new eeprom.

Even if the content was corrupted in the old eeprom, when you make new settings and save them, the cpu should rewrite the eeprom content as it is done when you interchanged that two eeprom.
Actually, if this is working this way, than the corrupted data in the eeprom would be overwritten with good data and the unit should work again.
In this case no need to change the eeprom.

What could cause that kind of data corruption?
I think the cpu firmware takes care about data corruption and there should
be some sort of data integrity check in the system like a really often used
CRC check and the checksum is written inside the eeprom.

I'm a bit suspicious does the manufacturer used an 8k eeprom to save only lets say 200 byte long parameters.
There must be much more think in there.
Do you ever investigated the content of the eeprom?
I would like to see some of them.

Are you checked the clock line and data I/O line from the cpu to the eeprom?
Very often a bad cap or some sort of bad pull up/down resistor can cos a messy data transfer or a bad timing so the data would be not transmitted to the eep
correctly. Or several other things can also cos a bad content.

At the end, could it be, does you got a sort of bad solder joint on the old eep legs, and when you changed it with a new one that solved your problem?

But, however, it is an interesting repair article, nice to hear does here are peoples on the Earth who care and can save electronic devices from the junk and so the surrounding environment too like you.

Keep up and my best regards.

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By: Robert Calk Jr.

Robert Calk Jr. — Wed, 16 Jan 2019 12:32:30 +0000

Good job, Suranga.

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By: Albert van Bemmelen

Albert van Bemmelen — Wed, 16 Jan 2019 10:22:03 +0000

Understood. The screen was first partly black on the left side and after replacing the eeprom by a new one the screen setting changed by only showing a top partly black screen instead. And you were almost sure that it was not the processor that was at fault, and that reprogramming its eeprom settings would work. Very professional repair!

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By: Parasuraman S

Parasuraman S — Wed, 16 Jan 2019 08:55:38 +0000

Good job, Suranga! EEPROM fault is not that easy to find out! You are an expert!

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