Re-flashing of Bios with computer turned on

  • Thread starter Thread starter RedRider
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RedRider

I have a P4P-800 that the bios chip needs to be reflashed. I have a chip
remover tool, and another P4P-800 that is running. Can I safely remove the
working bios chip when the computer is on, replace it with the chip that
needs to be re-flashed, and perform the reflash.

I am concerned with shorting out the board or working chip.
 
I have a P4P-800 that the bios chip needs to be reflashed. I have a chip
remover tool, and another P4P-800 that is running. Can I safely remove the
working bios chip when the computer is on, replace it with the chip that
needs to be re-flashed, and perform the reflash.

I am concerned with shorting out the board or working chip.
Click to expand...

This is known as hot flashing.... it is possible, but highly risky.
I've done it twice successfully over the years to rescue a system where I had
little to lose.
It requires great care, and by its very nature is risky!

Mike
 
RedRider said:
I have a P4P-800 that the bios chip needs to be reflashed. I have a chip
remover tool, and another P4P-800 that is running. Can I safely remove the
working bios chip when the computer is on, replace it with the chip that
needs to be re-flashed, and perform the reflash.

I am concerned with shorting out the board or working chip.
Click to expand...

You could buy a BIOS Savior, plug in into the working system,
program the EEPROM soldered to the BIOS Savior, then plug it into
the non-working system, and use it to program the bad EEPROM.
A BIOS Savior has its own EEPROM, plus room for another EEPROM.
It costs around $25 or so, and the only difficult part, is finding
a vendor.

If you want to do a hot flash, be aware of the orientation of
the device, and that a rotation of the device or even touching
the pins of the chip to the wrong pins on the socket, could cause
a problem. For example, on one device pinout I looked at, a
180 degree rotation will result in power being applied to the
device in reverse (i.e. VCC and GND switch roles).

It would help if the extractor was an insulator, but the two tools
I've worked with had metal teeth (the lip that fits under
the device), and it also wouldn't be healthy for the tool to touch
pins either.

Having given all these cautions, yes, someone in this group did
manage to hot flash a PLCC. So, yes, it has been done.

With the power off, pull and reinsert the EEPROM about a half
dozen times, to loosen up the pins a bit, and make the real
experiment a little less nerve wracking. As I've pulled and
inserted at least a hundred of these, it helps to practice.

Consider it being like "double or nothing" at Los Vegas :-)
I've pulled and inserted both DIP and PLCC devices, and some
days, that PLCC just flies around the socket when you are
trying to reinsert it. (It is a lot like dropping dice on
a hard table top.) So, practicing first will give you some
idea of whether you have the dexterity and control required
to guarantee success. The DIP is a LOT easier.

Paul
 
Paul said:
You could buy a BIOS Savior, plug in into the working system,
program the EEPROM soldered to the BIOS Savior, then plug it into
the non-working system, and use it to program the bad EEPROM.
A BIOS Savior has its own EEPROM, plus room for another EEPROM.
It costs around $25 or so, and the only difficult part, is finding
a vendor.

If you want to do a hot flash, be aware of the orientation of
the device, and that a rotation of the device or even touching
the pins of the chip to the wrong pins on the socket, could cause
a problem. For example, on one device pinout I looked at, a
180 degree rotation will result in power being applied to the
device in reverse (i.e. VCC and GND switch roles).

It would help if the extractor was an insulator, but the two tools
I've worked with had metal teeth (the lip that fits under
the device), and it also wouldn't be healthy for the tool to touch
pins either.

Having given all these cautions, yes, someone in this group did
manage to hot flash a PLCC. So, yes, it has been done.

With the power off, pull and reinsert the EEPROM about a half
dozen times, to loosen up the pins a bit, and make the real
experiment a little less nerve wracking. As I've pulled and
inserted at least a hundred of these, it helps to practice.

Consider it being like "double or nothing" at Los Vegas :-)
I've pulled and inserted both DIP and PLCC devices, and some
days, that PLCC just flies around the socket when you are
trying to reinsert it. (It is a lot like dropping dice on
a hard table top.) So, practicing first will give you some
idea of whether you have the dexterity and control required
to guarantee success. The DIP is a LOT easier.

Paul
Click to expand...

I often need to hot-flash when repairing boards, so I bought a ZIF
socket and plugged it into the existing socket on my bench board - much
easier. I wonder if there's an equivalent available for PLCC devices?

P2B
 
P2B said:
I often need to hot-flash when repairing boards, so I bought a ZIF
socket and plugged it into the existing socket on my bench board - much
easier. I wonder if there's an equivalent available for PLCC devices?

P2B
Click to expand...

You could look through this page of links, but don't hold
your breath. I really think the BIOS Savior is as good
a mechanism as any, and it is cheap compared to buying
any adapter devices from this page:

http://www.rfcafe.com/vendors/components/connectoradapter_links.htm

HTH,
Paul
 
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