Sanyo DP55441 - No brightness control

[karthur]

Recently picked up a Sanyo DP55441. Set has a few issues:
1. When I turn it on, I always have to select either "Store" or "Home" on the menu (see attachment).
2. It forgets which input I was using last, so I have to change the input setting everytime.
3. The controls for Brightness, Contrast, Saturation, Hue and Sharpness are not available from the menu (see attachment).

Besides these issues the set works good, no other issues that I know of.

I am thinking all three are related and its probably the main board. I have looked at the main board and the power board, but see no visible damage.

Any ideas?

Thanks

[lotas]

This is usually due to bad memory (Eeprom, Spi Flash).

[karthur]

How do I fix it?

[lotas]

Originally Posted by karthur

How do I fix it?

If you have a programmer, then you need to unsolder this spi flash (from the photo of your motherboard, I no longer saw other Eeprom and spi flash). Read the contents in your memory and save the dump. Buy a new flash and load your saved dump into it and solder it in place of the old flash.

[dskall]

https://www.shopjimmy.com/sanyo-431c...8aAkWZEALw_wcB

[nomoresonys]

probably bad memory as mentioned, did you try an update and or factory reset?

[karthur]

Originally Posted by nomoresonys

probably bad memory as mentioned, did you try an update and or factory reset?

I did do a reset from the onscreen menu, but I have not tried an update. Is there a certain key sequence to get into a service mode or some other way to get into a deeper reset?

I searched on Sanyo-av.com for my model No. There is no update listed there.

[karthur]

Originally Posted by lotas

If you have a programmer, then you need to unsolder this spi flash (from the photo of your motherboard, I no longer saw other Eeprom and spi flash). Read the contents in your memory and save the dump. Buy a new flash and load your saved dump into it and solder it in place of the old flash.

Here is a picture of my board. There are several of those on the board.

I don't have a programmer. Would one of these work?

Thanks

[lotas]

If you see microcircuits on the board 24Cxx, then this is Eeprom, if there are 25Xxx, then this is Spi flash, but the markings are not visible in the photo, rather these are DC / DC converters in the Sop-8 package. As for the programmer - yes it will do.

[karthur]

Originally Posted by lotas

If you see microcircuits on the board 24Cxx, then this is Eeprom, if there are 25Xxx, then this is Spi flash, but the markings are not visible in the photo, rather these are DC / DC converters in the Sop-8 package. As for the programmer - yes it will do.

Let me get the back off again and I will take a closer look.

[lotas]

Originally Posted by karthur

Let me get the back off again and I will take a closer look.

You can also look at the back of the board.

[lotas]

Usually, the eeprom or spi flash is marked with a dot or a strip of paint (indicating that the microcircuit has been programmed and tested).

[karthur]

Originally Posted by lotas

Usually, the eeprom or spi flash is marked with a dot or a strip of paint (indicating that the microcircuit has been programmed and tested).

The only one I found with "25" on it (see attachment) and it has the paint mark. I did not see any with "24" on them. Do I need to look on back of board for one with "24" on it?

[karthur]

Went ahead and flipped the board over. Found this one with a paint mark on it too, Number on it reads 25L8xxxx if it matters. I think the xxxx is 036F, but its covered by the paint.

[lotas]

Maybe, maybe not. But rather it is not there.

[lotas]

On the other hand, we do not need 25xxx, it is rather responsible for scarlet (matrix settings).

[karthur]

Originally Posted by lotas

On the other hand, we do not need 25xxx, it is rather responsible for scarlet (matrix settings).

Both of them are 25xxx. Is the one on the front the one that possibly needs to be replaced? Are there certain specifications that I need to look for to replace it with? Surely there are other sources for this that are not $16.

Thanks

[lotas]

Wipe off the paint so that the full marking can be seen.

[karthur]

Originally Posted by lotas

Wipe off the paint so that the full marking can be seen.

Here is close-ups of both chips. The numbers are:

Front Chip
MXIC MX
25L3206E
M2I-12G
3F652000
L111676

Back Chip:
MXIC MX
25L8006E
M2I-12G
3E660500
Z105075

[lotas]

For 16 bucks there is an already programmed flash, you need to find the same or an analogue (the size of the internal memory), they cost a penny.

https://aliexpress.ru/popular/mx25l3206em2i-12g.html