GA-m57SLI-S4 Dual Linux Bios DIY
History:
- Added Resistor size.
- Describe function of resistor
- Add suggestions from Andreas B. Mundt
This is a short instruction how to utilize the empty flashrom pads on a GA-m57SLI-S4 (rev. 1.0).
Please realize that nobody will take responsibility if the Motherboard seduces
your grandmother or other nasty stuff happens.
Currently it is not known if the SuperIO Chip is connected to the INIT# pins (the ones where the cables 1 and 3 go). If yes the whole procedure may be harmfull to your mainboard even if you manage to solder successfully ;-)... but it works for me!
Andreas has the following suggestions:
Two things can perhaps be added to ST's
instructions/wiki:
- I used a 100k standard resistor (no SMD!)
- the pull-down current to ground is in both cases about 0.033mA.
This is consistent with Ohm's law: I=U/R=3.3V/100kOhm=0.033mA for the added
chip. It shows that the soldered chip is pulled up also with a 100kOhm
resistor and no other chip should be damaged by that(?). Reading and writing
works without problems on both chips.
Requirements:
- You should have a good electronic soldering iron with a smd soldering tip,
- some colophonium,
- a smd resistor,(in the range of 4.7k - 20k ohms. The author used an 4.7k ohms resistor because he had one of these at hand.) Probably a 0603.
- a PLCC32 socket and and a "SST 49LF040" or and "PM 49FL004" flash rom,
- a switch or jumper with three pins,
- and three wires.
klick for larger version
Soldering:
- Socket: The socket is soldered according to the above image. There is no need to use solder
since there is enough solder on the pads of the Mainboard. But putting some colophonium on the pads of the socket helps soldering. Solder one pin at a corner and the pin at the opposite side. Check if the socket is really right on the pads of the mainboard. Solder the remaining pins by pressing the solder iron thoroughly on the pins of the socket onto the corresponding mainboard pin.
- Solder the resistor to the mainboard, take a look at the image above for placement. The resistor pulls up the INIT# pin of the flash-rom in the newly added PLCC32 socket.
- Solder the cables 1 and 3 to the two marked pins according to the image above.
- Solder the cable 2 to ground (location see image below).
- Solder the switch/jumper to the cables 1 2 and 3. Make sure that only 1-2 or (mutually!) 2-3 is shortened at a time.
After that you should take an multimeter and check that there is no short-circuit at the soldered pins.Pins 3 and 4 of the PLCC32 socket are shortened by the mainboard. Don't forget to put the flash-rom into the socket.
The result should look s.t. like this (switch not shown):
klick for larger version
If you have any suggestions/corrections please let me know:
st at iss tu-darmstadt de
