I may post the long story later, but the short story is that I have
a motherboard and a DDR DIMM where pins 3 and 100 on the DIMM and
the corresponding socket are toast. The gold on the DIMM contacts
is completely gone, and the socket is charred in those positions.

The motherboard was said to be dead when the DIMM was installed.

I've taken out the DIMM, and I put another DIMM into the computer
in a different socket, and it seems to work fine.

I took the burned DIMM and put it into another computer, and it
seems to work fine too.

What happened?

(I checked the DDR pinout. Pins 3 and 100 are both grounds.)

Unregistered wrote:
I may post the long story later, but the short story is that I have
a motherboard and a DDR DIMM where pins 3 and 100 on the DIMM and
the corresponding socket are toast. The gold on the DIMM contacts
is completely gone, and the socket is charred in those positions.

The motherboard was said to be dead when the DIMM was installed.

I've taken out the DIMM, and I put another DIMM into the computer
in a different socket, and it seems to work fine.

I took the burned DIMM and put it into another computer, and it
seems to work fine too.

What happened?

(I checked the DDR pinout. Pins 3 and 100 are both grounds.)

What else but lightning or some kind of surge damage?

Could the socket have been swapped from another computer?

Mark Z.

"Unregistered" wrote in message
. ..
I may post the long story later, but the short story is that I have
a motherboard and a DDR DIMM where pins 3 and 100 on the DIMM and
the corresponding socket are toast. The gold on the DIMM contacts
is completely gone, and the socket is charred in those positions.

The motherboard was said to be dead when the DIMM was installed.

I've taken out the DIMM, and I put another DIMM into the computer
in a different socket, and it seems to work fine.

I took the burned DIMM and put it into another computer, and it
seems to work fine too.

What happened?

(I checked the DDR pinout. Pins 3 and 100 are both grounds.)

Someone probably managed to put it in backwards at an angle. Then, on power
on the traces vaporized. I have a couple of PC133 256MB that have the same
problem(different pins). They still work fine because there are multiple gnd
and vcc pins.....Paul

catguy wrote:
"Unregistered" wrote:
I may post the long story later, but the short story is that I have
a motherboard and a DDR DIMM where pins 3 and 100 on the DIMM and
the corresponding socket are toast. The gold on the DIMM contacts
is completely gone, and the socket is charred in those positions.

The motherboard was said to be dead when the DIMM was installed.

I've taken out the DIMM, and I put another DIMM into the computer
in a different socket, and it seems to work fine.

I took the burned DIMM and put it into another computer, and it
seems to work fine too.

What happened?

(I checked the DDR pinout. Pins 3 and 100 are both grounds.)

Someone probably managed to put it in backwards at an angle. Then, on power
on the traces vaporized. I have a couple of PC133 256MB that have the same
problem(different pins). They still work fine because there are multiple gnd
and vcc pins.....Paul


Nice idea, but it doesn't quite fit the circumstances.

The burned positions on the DIMM match the correct positions on the
socket, and those positions are also burned. If it fried when it was
put in backwards, then they shouldn't match.


Here's another clue that may help: someone was apparently trying to
install more memory into the computer when this happened. (When I got
the computer back, there was only the single module, though.)

Maybe the additional module somehow caused power to be fed back through
those two pins on the existing module?

"Unregistered" wrote in message
. ..

Nice idea, but it doesn't quite fit the circumstances.

The burned positions on the DIMM match the correct positions on the
socket, and those positions are also burned. If it fried when it was
put in backwards, then they shouldn't match.


Here's another clue that may help: someone was apparently trying to
install more memory into the computer when this happened. (When I got
the computer back, there was only the single module, though.)

Maybe the additional module somehow caused power to be fed back through
those two pins on the existing module?

Odd but will we ever know now?

Homer J Simpson wrote:
"Unregistered" wrote:

Nice idea, but it doesn't quite fit the circumstances.

The burned positions on the DIMM match the correct positions on the
socket, and those positions are also burned. If it fried when it was
put in backwards, then they shouldn't match.


Here's another clue that may help: someone was apparently trying to
install more memory into the computer when this happened. (When I got
the computer back, there was only the single module, though.)

Maybe the additional module somehow caused power to be fed back through
those two pins on the existing module?

Odd but will we ever know now?


I don't know the answer, if that's what you mean.

I was hoping some smart people here could help me understand what happened.

I had sold this computer to somebody. It was working fine. The person
I sold it to said she took it to a friend to install more memory. They
say that it fried before they fooled with it. I don't believe them.

Not that it really matters now, but I really would like to understand
what happened.

Unregistered wrote:
I had sold this computer to somebody. It was working fine. The person
I sold it to said she took it to a friend to install more memory. They
say that it fried before they fooled with it. I don't believe them.

Not that it really matters now, but I really would like to understand
what happened.

There are many kinds of voltages, used for memory. Some computers, such as the
one I am using now takes both PC133 SDRAM or 266mHz (DDR RAM). The voltages
are different and if you put SDRAM voltage on DDR RAM, you will burn it out.

Since the DDR RAM and SDRAM use slightly different sockets, it's usually not an
issue.

The motherboard is "SMART", it detects the type of RAM present and adjusts
the voltage properly. HOWEVER if you put BOTH DDR and SDRAM in the computer
at the higher voltage is used on both sockets, burning out the DDR RAM.

If you look at the manual for the motherboard, you will see it.

If this is the case, someone tried to use both types at the same time
and damaged the motherboard and the memory. If it was you, then they
are right. If it was not ........

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

Unregistered ha escrito:

catguy wrote:


Nice idea, but it doesn't quite fit the circumstances.

The burned positions on the DIMM match the correct positions on the
socket, and those positions are also burned. If it fried when it was
put in backwards, then they shouldn't match.


Here's another clue that may help: someone was apparently trying to
install more memory into the computer when this happened. (When I got
the computer back, there was only the single module, though.)

Maybe the additional module somehow caused power to be fed back through
those two pins on the existing module?

Probably they tried to install more memory with the computer turned on,
or they turned on the computer by accident while they were installing
the DIMM.

Geoffrey S. Mendelson wrote:
Unregistered wrote:
I had sold this computer to somebody. It was working fine. The person
I sold it to said she took it to a friend to install more memory. They
say that it fried before they fooled with it. I don't believe them.

Not that it really matters now, but I really would like to understand
what happened.

There are many kinds of voltages, used for memory. Some computers, such as the
one I am using now takes both PC133 SDRAM or 266mHz (DDR RAM). The voltages
are different and if you put SDRAM voltage on DDR RAM, you will burn it out.

Since the DDR RAM and SDRAM use slightly different sockets, it's usually not an
issue.

The motherboard is "SMART", it detects the type of RAM present and adjusts
the voltage properly. HOWEVER if you put BOTH DDR and SDRAM in the computer
at the higher voltage is used on both sockets, burning out the DDR RAM.

If you look at the manual for the motherboard, you will see it.

If this is the case, someone tried to use both types at the same time
and damaged the motherboard and the memory. If it was you, then they
are right. If it was not ........

I don't believe you are correct. DDR DIMM sockets have a little bump in
the middle, the exact position of which is placed according to the required
voltage of the DIMM module. In fact, the DIMM socket has "2.50V" stamped
into it next to the bump. Only 2.5V DIMMs should fit into this socket, or
else the bump in the socket won't line up with the notch in the DIMM.

I sold the computer with a single DIMM in it, and it was working fine.
It did not have a problem until the customer's friend started fooling with it.


Here's my reference regarding the voltage:

http://www.technick.net/public/code/...sdram_dimm_184


Still unexplained is why the two GROUND pads/contacts fried.

On Sat, 26 Aug 2006 01:39:56 -0700, Unregistered wrote:

I may post the long story later, but the short story is that I have
a motherboard and a DDR DIMM where pins 3 and 100 on the DIMM and
the corresponding socket are toast. The gold on the DIMM contacts
is completely gone, and the socket is charred in those positions.

The motherboard was said to be dead when the DIMM was installed.

I've taken out the DIMM, and I put another DIMM into the computer
in a different socket, and it seems to work fine.

I took the burned DIMM and put it into another computer, and it
seems to work fine too.

What happened?

(I checked the DDR pinout. Pins 3 and 100 are both grounds.)


I would guess that a short occurred somewhere on the DIMM. It could
have been a ceramic cap that shorted, or possibly a short between
layers of the board. Maybe a foreign object like a screw hit the
DIMM. This caused the pins closest to the short to burn. Since there
are lots of Vcc and ground pins, it could still work as long as the
short is either no longer present, or was removed from the circuit
when the right traces melted.
Andy Cuffe

Unregistered wrote:
I may post the long story later, but the short story is that I have
a motherboard and a DDR DIMM where pins 3 and 100 on the DIMM and
the corresponding socket are toast. The gold on the DIMM contacts
is completely gone, and the socket is charred in those positions.

The motherboard was said to be dead when the DIMM was installed.

I've taken out the DIMM, and I put another DIMM into the computer
in a different socket, and it seems to work fine.

I took the burned DIMM and put it into another computer, and it
seems to work fine too.

What happened?

(I checked the DDR pinout. Pins 3 and 100 are both grounds.)


I looked again carefully at the parts involved, and I discovered that
my original analysis was incorrect.

The DIMM was inserted backwards.

Mystery solved (as far as I care).

Thanks to those who offered suggestions.

Unregistered wrote in
:



I looked again carefully at the parts involved, and I discovered that
my original analysis was incorrect.

The DIMM was inserted backwards.

Mystery solved (as far as I care).

Thanks to those who offered suggestions.


You can insert them backwards? I know the 168-pin type is keyed so you
cannot insert them backwards. (Notches about 10% and 60% distance from
the end.)

Puckdropper
--
Wise is the man who attempts to answer his question before asking it.

To email me directly, send a message to puckdropper (at) fastmail.fm

"Puckdropper" wrote in message
reenews.net...

You can insert them backwards?

I know people who can insert anything into anything else in any
orientation - usually except the correct one.

Unregistered wrote:
I don't believe you are correct. DDR DIMM sockets have a little bump in
the middle, the exact position of which is placed according to the required
voltage of the DIMM module. In fact, the DIMM socket has "2.50V" stamped
into it next to the bump. Only 2.5V DIMMs should fit into this socket, or
else the bump in the socket won't line up with the notch in the DIMM.

That's correct, you can not put them both in the same socket. My point,
which obviously I did not fully explain, is that some motherboards have
BOTH DDR DIMM and SDRAM DIMM sockets.

SDRAM DIMMs are 3.3 volt, DDR DIMMs are 2.5 volt. On motherboards that
have BOTH, if there is SDRAM in a socket, the voltage on BOTH sets of sockets
is 3.3 volts. It's poor design, but they all do it.



I sold the computer with a single DIMM in it, and it was working fine.
It did not have a problem until the customer's friend started fooling with it.

That's pretty normal. Almost everyone has a friend who should not be allowed
to touch a computer, but thinks they know everything.

He probably had hit the power button and put the computer in "sleep" mode,
without actually turning it off or unplugging it.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

Puckdropper wrote:
Unregistered wrote:

I looked again carefully at the parts involved, and I discovered that
my original analysis was incorrect.

The DIMM was inserted backwards.

Mystery solved (as far as I care).

Thanks to those who offered suggestions.

You can insert them backwards? I know the 168-pin type is keyed so you
cannot insert them backwards. (Notches about 10% and 60% distance from
the end.)

The 184 DDR DIMMs are also keyed so you "can't" insert them backwards.

I imagine that one side was fully plugged in and the other side wasn't.
Perhaps the motherboard was bowed out in the middle where the key wasn't
going into the notch. I don't know.