Полная версия: faulty DC bios, pins owned
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hi all, i bought some faulty DC from someone who tried to install a regionfree bios.

[Изображение: mini_557901DCbios.jpg]

with the schematic, i noticed that pin 20, 22, 25 are unused, anyone can confirm ?

about pin 1 and 23, i have to find the 5v somewhere else, am i right ? any advice on this point ?

thanks in advance.
All right. Get the power at any place, where you more convenient. For example from GD-ROM port, it's have 3.3v and 5v for any flashchips.
awesome Mr SWAT.

many thanks for the fast answer Smile
oh i just realized that it was a VA1 board and about leg 23 it must not be lifted. what should i do ?

edit : ok i scratched a bit the motherboard and found the attachment to the 3.3v via Big Grin

i hope my repear will be a success !

[Изображение: mini_636174dcbios2.jpg]
Good luck Smile
back for more,

i'm desperate for this one, i took time to do perfect soldering, tested everything with multimeter, all broken tracks are now ok and still don't boot Sad

[Изображение: mini_499619dcbios4.jpg]

i can't believe it's dead, SEGA never die, doesn't it ?
I don't see where connected CE pin (not connected to reset and power with resistor). Check schematic http://www.dc-swat.ru/blog/hardware/16.html
You flash firmware to this chip before solder?
hey swat, you mean i have to place 10k betwin reset and CE (lifted ?) ? i have 3.3k and 7.5k resistors only, i ll make 9,9k with 3 of them.

about the chip, the guy who failed gave it to me (hope he flash better than he solder ^^)

oh while i'm here, i started also the second DC failed, and doesn't boot too...i'm pretty sure all solders are fine.

[Изображение: mini_670747dc3bios1.jpg]
[Изображение: mini_779744dc3bios2.jpg]
[Изображение: mini_662094dc3bios3.jpg]
If CE pin not connected to the power (as in datasheet), the flash chip can will not work.
This motherboard with 5v or 3.3v bios chip version? You solder this pin direct...

Why you do not soldered it over a Sega bios ROM?
It will serve you in the future as a backup boot. if you write a non-working BIOS for example. Otherwise you will have to unsolder it again.
And you can be check motherboard work. If your DC boot fine with the original ROM, then new flash chip is damaged Sad
like this ?

[Изображение: mini_76496520140324112435.jpg]

i got 3 faulty DC without original bios, all VA1 (3,3v), the same guy gave me 3 programmed chips with them, if i had choice i would do the piggyback.

in other hand, i found a post that show final pic of a working DC with full remplacment chip, i don't see any connection betwin CE and power.

Of course it's works if you replace 3.3v bios to other 3.3v flash chip, I'm just trying to find reason.
I'm sorry, I'm forget, you said me about motherboard before.
So maybe the flash chip can be broken before you Sad
i just sent PM to Bad_ad84 for some programmed chip 3.3v, waiting shipping.
any idea for alternative place for pins 34 and 35, thanks,
(28.10.2014 02:36)Gromber писал(а): [ -> ]any idea for alternative place for pins 34 and 35, thanks,

Try find it here http://www.dc-swat.ru/download/doc/schem...iagram.pdf
URL ссылки