Fixing inconsistent RAM detection

I have two identical 1Gb RAM chips installed, and they are not always detected. I have even had both BIOS and WIN say that RAM is 1.5Gb [as well as 1Gb and 2Gb]. Swapping the chips around seems to fix it for THAT session, and then what is detected at next reboot is an adventure/uncertain.

On 2/17/2014 4:31 AM, jphilippa wrote:

I have two identical 1Gb RAM chips installed, and they are not always
detected. I have even had both BIOS and WIN say that RAM is 1.5Gb [as
well as 1Gb and 2Gb]. Swapping the chips around seems to fix it for THAT
session, and then what is detected at next reboot is an
adventure/uncertain.

Try cleaning the RAM contacts with a clean pencil eraser. Hopefully that
would take care of it. Don't use other cleaners until you try the eraser
trick first. As this one seems to last the longest.

--
Bill
Gateway M465e ('06 era) - Thunderbird v24.3.0
Centrino Core2 Duo T5600 1.83GHz - 4GB - Windows XP SP2

BillW50 wrote:
On 2/17/2014 4:31 AM, jphilippa wrote:

I have two identical 1Gb RAM chips installed, and they are not always
detected. I have even had both BIOS and WIN say that RAM is 1.5Gb [as
well as 1Gb and 2Gb]. Swapping the chips around seems to fix it for THAT
session, and then what is detected at next reboot is an
adventure/uncertain.

Try cleaning the RAM contacts with a clean pencil eraser. Hopefully that
would take care of it. Don't use other cleaners until you try the eraser
trick first. As this one seems to last the longest.


I generally recommend against this, for a first step.

Contact systems:

Tin on tin, or gold on gold.
Tin on tin, relies on the scraping of protective oxide
off the outside of the metal. This gives a gas-tight connection.

Gold on gold involves precious metals on both sides. At least,
as long as there is some gold left. Gold "slides" against its
gold partner. Friction level is lower. Oxides don't form on gold,
which is why it is used.

Mixing gold and tin, is not recommended.

To clean a RAM slot:

1) Turn off computer power. Unplug, if you are unsure of whether
+5VSB is still running. Wear an antistatic strap. A commercial
antistatic strap, has a series resistor, and brings the chassis
of the computer, to human body potential (so the RAM doesn't
get zapped by static). Clip the strap onto an I/O screw on the
back of the computer.

2) Pull the stick of RAM. Place it in an antistatic bag.
Touch the inside of the bag with your finger, to bring it
to the same potential as the rest of your gear.

3) Using a strong light and magnifying glass, inspect the
socket for bent or broken pins.

4) Inspect the DIMM. Look for surface dirt.

a) If the DIMM and socket are clean, simply reinsert. The
wiping action of the contacts, is sufficient to establish
a connection. In many cases, the DIMM simply was not down
into the socket fully. Verify the cam ejectors are in the
full upright position.

b) If the DIMM is dirty, use isopropyl alcohol and a cloth
to remove the debris.

c) Only under the most dire circumstances would you apply an
abrasive. If the 10u gold plating is completely shot, perhaps
grinding the **** out of it with your pencil eraser is your
only option. Be prepared to have to do this, every few months.
It is habit forming.

*******

The BIOS uses two methods to sense the DIMM.

1) SMBUS, readout of SPD data. The BIOS uses this
as the estimated size. But, it uses a "trust but verify"
philosophy.

2) The second (sequential) step, is "poke and peek sizing".
The BIOS sets up a preliminary mapping, and does safe access
to the DIMM. It writes a value, and checks later whether it
can be read. If an address line is not making contact, it is
this test that catches it. Values for bytes are selected so
that the test resists "floating bus" false results.

It's even possible, for the test in (2), to correct for
an entirely wrong SPD chip. Some DIMMs were made once, where
the wrong SPD was soldered to the DIMM. And yet, the computer
was able to deal with the DIMM all the same.

The BIOS also does a memory test, but this is far from satisfactory.
I've had entire dead DIMMs, be missed by the "long" BIOS test. No
beep error code, machine tries to start, and crashes.

In this case, pressing on the DIMM or re-seating it
would be a first step. With the power off while you are fooling
with it. Some motherboards now (LGA2011) use DIMM slots with only
one ejector instead of two. And the user can never be sure the DIMM
is secure in these (poorly designed) DIMM slots.

Example of a proper antistatic strap.

http://www.radioshack.com/product/in...ductId=2260808

Have fun,
Paul

In ,
Paul typed:
BillW50 wrote:
On 2/17/2014 4:31 AM, jphilippa wrote:

I have two identical 1Gb RAM chips installed, and they are not
always detected. I have even had both BIOS and WIN say that RAM is
1.5Gb [as well as 1Gb and 2Gb]. Swapping the chips around seems to
fix it for THAT session, and then what is detected at next reboot
is an adventure/uncertain.

Try cleaning the RAM contacts with a clean pencil eraser. Hopefully
that would take care of it. Don't use other cleaners until you try
the eraser trick first. As this one seems to last the longest.

I generally recommend against this, for a first step.
[...]
c) Only under the most dire circumstances would you apply an
abrasive. If the 10u gold plating is completely shot, perhaps
grinding the **** out of it with your pencil eraser is your
only option. Be prepared to have to do this, every few months.
It is habit forming.

Actually I have found just the opposite. I learned this trick with a
pencil eraser first with those old TV tuners with mechanical contacts
from a very seasoned repairman. They were very sensitive to the
slightest contact problem. And there was two ways this was usually done.

1) The easy way. Pull the tuner knob off and spray inside with contact
cleaner and turn the selector around until all of the selections were
nice and clean.

2) The hard way. Removing the back of the TV. Removing the tuner.
Disassembling the tuner. Using a pencil eraser on each and every
contact. There is like a hundred of them. Put it all back together and
your done.

The difference between the contact cleaner/alcohol and the eraser method
was huge. As the former the problem would come back in about 6 months.
Repeat and maybe it would last 5 months. Repeat again and now it would
last 4 months. Get the idea? Do it once with the eraser and it would
last 20 years before the problem ever came back again even in a smoke
filled house. That is huge!

And it works on any kind of electrical contact. The only thing it is
worthless on is grimy and oily contacts. As all it does is contaminate
the eraser and makes it useless. So then you must use other methods.

Nor have I seem any evidence that a pencil eraser acts as an abrasive on
tin, copper, or gold. Did you ever see any evidence of that Paul? Even
under a 50x microscope I can't see any micro scratches or anything. All
it does is to remove oxidation and dirt. Maybe next time I am by a
scanning electron microscope, I can check again at say 100,000x
magnification if it does act as an abrasion. But I still don't think so.

And if you know about the hardness factor, I am sure you will find that
an eraser is softer than tin, copper, or gold. And in physics, it is
impossible for a softer material to scratch a harder one. An eraser
works on paper because the eraser is harder than the paper is. An eraser
on tin, copper, or gold is only going to remove the oxidation, dirt,
dust, etc.and wear down the eraser.

Problem with cleaners in general is they are never 100% pure. And they
will often leave a slight usually sticky residue. And they attract dirt,
dust, etc. like a magnet. Sure it works for a time, but you will have to
do it again and again later.

Tin on tin is the worst. If you even have to use the eraser trick again
and again (usually only happens on tin to tin), because it oxidizes very
fast. And I hope I got this right is a dielectric paste. Anyway the same
kind they use in boat trailer tail light bulbs and sockets. As it keeps
dirt, water, air, etc out and yet still allows contact. This works well
for those troublesome tin contacts.

--
Bill
Gateway M465e ('06 era) - OE-QuoteFix v1.19.2
Centrino Core2 Duo T5600 1.83GHz - 4GB - Windows XP SP2

BillW50 wrote:
In ,
Paul typed:
BillW50 wrote:
On 2/17/2014 4:31 AM, jphilippa wrote:
I have two identical 1Gb RAM chips installed, and they are not
always detected. I have even had both BIOS and WIN say that RAM is
1.5Gb [as well as 1Gb and 2Gb]. Swapping the chips around seems to
fix it for THAT session, and then what is detected at next reboot
is an adventure/uncertain.
Try cleaning the RAM contacts with a clean pencil eraser. Hopefully
that would take care of it. Don't use other cleaners until you try
the eraser trick first. As this one seems to last the longest.
I generally recommend against this, for a first step.
[...]
c) Only under the most dire circumstances would you apply an
abrasive. If the 10u gold plating is completely shot, perhaps
grinding the **** out of it with your pencil eraser is your
only option. Be prepared to have to do this, every few months.
It is habit forming.

Actually I have found just the opposite. I learned this trick with a
pencil eraser first with those old TV tuners with mechanical contacts
from a very seasoned repairman. They were very sensitive to the
slightest contact problem. And there was two ways this was usually done.

1) The easy way. Pull the tuner knob off and spray inside with contact
cleaner and turn the selector around until all of the selections were
nice and clean.

2) The hard way. Removing the back of the TV. Removing the tuner.
Disassembling the tuner. Using a pencil eraser on each and every
contact. There is like a hundred of them. Put it all back together and
your done.

The difference between the contact cleaner/alcohol and the eraser method
was huge. As the former the problem would come back in about 6 months.
Repeat and maybe it would last 5 months. Repeat again and now it would
last 4 months. Get the idea? Do it once with the eraser and it would
last 20 years before the problem ever came back again even in a smoke
filled house. That is huge!

And it works on any kind of electrical contact. The only thing it is
worthless on is grimy and oily contacts. As all it does is contaminate
the eraser and makes it useless. So then you must use other methods.

Nor have I seem any evidence that a pencil eraser acts as an abrasive on
tin, copper, or gold. Did you ever see any evidence of that Paul? Even
under a 50x microscope I can't see any micro scratches or anything. All
it does is to remove oxidation and dirt. Maybe next time I am by a
scanning electron microscope, I can check again at say 100,000x
magnification if it does act as an abrasion. But I still don't think so.

And if you know about the hardness factor, I am sure you will find that
an eraser is softer than tin, copper, or gold. And in physics, it is
impossible for a softer material to scratch a harder one. An eraser
works on paper because the eraser is harder than the paper is. An eraser
on tin, copper, or gold is only going to remove the oxidation, dirt,
dust, etc.and wear down the eraser.

Problem with cleaners in general is they are never 100% pure. And they
will often leave a slight usually sticky residue. And they attract dirt,
dust, etc. like a magnet. Sure it works for a time, but you will have to
do it again and again later.

Tin on tin is the worst. If you even have to use the eraser trick again
and again (usually only happens on tin to tin), because it oxidizes very
fast. And I hope I got this right is a dielectric paste. Anyway the same
kind they use in boat trailer tail light bulbs and sockets. As it keeps
dirt, water, air, etc out and yet still allows contact. This works well
for those troublesome tin contacts.


You're comparing a rotating assembly in a dirty environment,
to a DIMM making contact with a socket once. Once the contact
is made, the dust swirling around it doesn't matter (within reason).
A moist corrosive atmosphere and packed dust, does matter.
Corrosive atmospheres exist in industrial settings.

Due to the cheapness of the gold plating on computer electronics,
there is always the possibility of pinholes in the finish. I've
seen it on products I've bought here. In the telecom industry,
we specified 50u gold finish, and that provides a measure
of margin. The 10u gold finish computer stuff uses, with pinholes
in it, is a definite compromise. I still don't see an incentive
to use abrasives on it though. The metal underneath the gold,
is no substitute for the gold.

And tin on tin is fine. The only point of mentioning the
two systems, is to mention not to mix them. Many years ago,
there was the possibility of a consumer mixing the metals.
DIMMs now are gold on gold, even if the gold is a wee bit thin.

I don't even need a microscope. The gold finish has pinholes
even when it's new. I don't even need to look for it. Have
you ever seen an improperly plated video card, with gold
missing entirely on some of the pins ? I have. I don't need
a microscope for that. A pencil eraser is an abrasive.
The kind on the end of a pencil, the pink eraser. It's
abrasive, as it'll rip a sheet of paper to shreds after
you've used it a bit. And if you use a gum eraser, it
could leave residue behind.

If you use no chemicals at all, and just re-seat the
DIMM, there's no chance of a chemical residue left
behind. That's why I treat it as the number 1 option.

When I bought a new computer, and the Ethernet cable
wasn't making contact with a pin on the back of the computer,
inserting it five times was enough to clean the computer
pin. And I never had any further trouble with it.
No chemicals. Wiped clean by the connector action.

Paul

In ,
Paul typed:
BillW50 wrote:
In ,
Paul typed:
BillW50 wrote:
On 2/17/2014 4:31 AM, jphilippa wrote:
I have two identical 1Gb RAM chips installed, and they are not
always detected. I have even had both BIOS and WIN say that RAM is
1.5Gb [as well as 1Gb and 2Gb]. Swapping the chips around seems to
fix it for THAT session, and then what is detected at next reboot
is an adventure/uncertain.
Try cleaning the RAM contacts with a clean pencil eraser. Hopefully
that would take care of it. Don't use other cleaners until you try
the eraser trick first. As this one seems to last the longest.
I generally recommend against this, for a first step.
[...]
c) Only under the most dire circumstances would you apply an
abrasive. If the 10u gold plating is completely shot, perhaps
grinding the **** out of it with your pencil eraser is your
only option. Be prepared to have to do this, every few months.
It is habit forming.

Actually I have found just the opposite. I learned this trick with a
pencil eraser first with those old TV tuners with mechanical contacts
from a very seasoned repairman. They were very sensitive to the
slightest contact problem. And there was two ways this was usually
done. 1) The easy way. Pull the tuner knob off and spray inside with
contact cleaner and turn the selector around until all of the
selections were nice and clean.

2) The hard way. Removing the back of the TV. Removing the tuner.
Disassembling the tuner. Using a pencil eraser on each and every
contact. There is like a hundred of them. Put it all back together
and your done.

The difference between the contact cleaner/alcohol and the eraser
method was huge. As the former the problem would come back in about
6 months. Repeat and maybe it would last 5 months. Repeat again and
now it would last 4 months. Get the idea? Do it once with the eraser
and it would last 20 years before the problem ever came back again
even in a smoke filled house. That is huge!

And it works on any kind of electrical contact. The only thing it is
worthless on is grimy and oily contacts. As all it does is
contaminate the eraser and makes it useless. So then you must use
other methods. Nor have I seem any evidence that a pencil eraser acts
as an
abrasive on tin, copper, or gold. Did you ever see any evidence of
that Paul? Even under a 50x microscope I can't see any micro
scratches or anything. All it does is to remove oxidation and dirt.
Maybe next time I am by a scanning electron microscope, I can check
again at say 100,000x magnification if it does act as an abrasion.
But I still don't think so. And if you know about the hardness
factor, I am sure you will find
that an eraser is softer than tin, copper, or gold. And in physics,
it is impossible for a softer material to scratch a harder one. An
eraser works on paper because the eraser is harder than the paper
is. An eraser on tin, copper, or gold is only going to remove the
oxidation, dirt, dust, etc.and wear down the eraser.

Problem with cleaners in general is they are never 100% pure. And
they will often leave a slight usually sticky residue. And they
attract dirt, dust, etc. like a magnet. Sure it works for a time,
but you will have to do it again and again later.

Tin on tin is the worst. If you even have to use the eraser trick
again and again (usually only happens on tin to tin), because it
oxidizes very fast. And I hope I got this right is a dielectric
paste. Anyway the same kind they use in boat trailer tail light
bulbs and sockets. As it keeps dirt, water, air, etc out and yet
still allows contact. This works well for those troublesome tin
contacts.

You're comparing a rotating assembly in a dirty environment,
to a DIMM making contact with a socket once. Once the contact
is made, the dust swirling around it doesn't matter (within reason).
A moist corrosive atmosphere and packed dust, does matter.
Corrosive atmospheres exist in industrial settings.

Actually no, but I know what you are saying and that is like the worst
case. But no, oxygen is highly corrosive to many things. Many metals and
even biological matter. Most food for example last longer void of oxygen
(vacuum sealed comes to mind). Even tin and copper doesn't do so well
around oxygen. Although copper isn't too terribly bad, but it is still
affected.

Due to the cheapness of the gold plating on computer electronics,
there is always the possibility of pinholes in the finish. I've
seen it on products I've bought here. In the telecom industry,
we specified 50u gold finish, and that provides a measure
of margin. The 10u gold finish computer stuff uses, with pinholes
in it, is a definite compromise. I still don't see an incentive
to use abrasives on it though. The metal underneath the gold,
is no substitute for the gold.

Oh yes, no doubt about that. Although for something to be abrasive, it
has to be equal in hardness or harder. Something less is meaningless.
Just watch those Corning Gorilla glass youtube videos. Anything less
hardness than Gorilla glass can't even scratch it. Use something just as
hard or harder and all bets are off.

And tin on tin is fine. The only point of mentioning the
two systems, is to mention not to mix them. Many years ago,
there was the possibility of a consumer mixing the metals.
DIMMs now are gold on gold, even if the gold is a wee bit thin.

I never liked tin on tin and tin and anything else was much better. The
worst case I ever saw was the Timex Sinclair 1000 (virtually the same as
Sinclair ZX-81, sort of). It used tin on tin with the expansion port. If
they used tin on copper I am sure would have been a huge improvement.
Those contacts required cleaning every week at least.

I recall one mentioned in a magazine that he rubbed mercury on the
contacts and he mentioned it worked great. I have no doubt this actually
worked. Two huge problems though. Mercury vapors caused the same thing
that happened to the mad hatter. Okay with enough ventilation, you might
be ok. But it won't take long before the mercury eats right through the
tin. I never heard anymore, but I don't think that story ended well.

I had two of them and one I kept stock and one I modified to the hilt.
And it could do anything a stock or modified one could do and totally
compatible with all Sinclair ZX-81 / Timex software. The stock one was
unbearable. So I cheated and coated the contacts with solder (tin and
lead). That really worked great. After all components are soldered to a
PCB with solder and that works well.

I don't even need a microscope. The gold finish has pinholes
even when it's new. I don't even need to look for it. Have
you ever seen an improperly plated video card, with gold
missing entirely on some of the pins ? I have. I don't need
a microscope for that. A pencil eraser is an abrasive.
The kind on the end of a pencil, the pink eraser. It's
abrasive, as it'll rip a sheet of paper to shreds after
you've used it a bit. And if you use a gum eraser, it
could leave residue behind.

Sure an eraser is abrasive to anything the same hardness or less. Paper
must be very close since they both are pretty abrasive to each other.
But use 500,000 sheets of paper against a screwdriver and guess which
one is abrasive one? It all has to do to the hardness factor.

If you use no chemicals at all, and just re-seat the
DIMM, there's no chance of a chemical residue left
behind. That's why I treat it as the number 1 option.

Any non zero force connection that is friction only always, this trick
works beautifully. Many cards works this way and just pull them out and
put them back (usually copper against copper or gold and gold) and they
are good for years. But this action is abrasive and it just works.

When I bought a new computer, and the Ethernet cable
wasn't making contact with a pin on the back of the computer,
inserting it five times was enough to clean the computer
pin. And I never had any further trouble with it.
No chemicals. Wiped clean by the connector action.

Of course, it was the abrasive action that did the job. ;-)

--
Bill
Gateway M465e ('06 era) - OE-QuoteFix v1.19.2
Centrino Core2 Duo T5600 1.83GHz - 4GB - Windows XP SP2

BillW50 wrote:
In ,
Paul typed:


When I bought a new computer, and the Ethernet cable
wasn't making contact with a pin on the back of the computer,
inserting it five times was enough to clean the computer
pin. And I never had any further trouble with it.
No chemicals. Wiped clean by the connector action.

Of course, it was the abrasive action that did the job. ;-)


Yes, but within the insertion rating of the connector.
If it was rated for 100 insertions, I inserted it 5 times,
I've used 5% of its life. That's a bit more controlled,
than scrubbing with an unknown amount of force, with
an abrasive of unknown characteristics.

Various connectors on computers, range from around
50 insertions to around 5000 insertions. Some can take
a lot of cycles, some much fewer. I don't have all the
numbers at hand, and don't even have an estimate for
how many the DIMM slot can take.

But I've ruined enough stuff by "lubricating" it,
to see interfering with stuff is not always the best
answer. Some of the things I've lubricated, only
ended up picking up more dirt, than if they'd
remained close to dry. So I don't use the "soak it"
method any more. On bicycle chains for example, I wipe
the lube off the chain when I'm finished (wipe it down good).
It still attracts dirt, but not as badly as just leaving
the lube on there. Same goes for lock de-icer. At one time,
I was a big fan of lock de-icer. But it becomes "habit-forming"
and seemed to be self-defeating in the long term. I've had
car doors freeze, and even inserting the lock de-icer
isn't freeing them up. Something is freezing, which the
liquid isn't touching.

Paul

"Paul" wrote

[snippage]

But it becomes "habit-forming"
and seemed to be self-defeating in the long term. I've had
car doors freeze, and even inserting the lock de-icer
isn't freeing them up. Something is freezing, which the
liquid isn't touching.

Paul

============

I began reseating boards in the era of the PDP8. Very rarely did I find a
chip that needed to be resocketed. IMHO wisdom and good practice evolves
with time. If a pencil eraser was sufficient to abrade gold, it would be
visible. Contrariwise, rubber is easily abraded onto contacts. That is why
good practice is to follow a pencil eraser with a queue tip and neat
isopropyl alcohol. Inspection of the rubber usually displays a black
deposit. Metals diffuse through metals. Base metals oxidize.

[quote=BillW50;3578663]On 2/17/2014 4:31 AM, jphilippa wrote:

I have two identical 1Gb RAM chips installed, and they are not always
detected. I have even had both BIOS and WIN say that RAM is 1.5Gb [as
well as 1Gb and 2Gb]. Swapping the chips around seems to fix it for THAT
session, and then what is detected at next reboot is an
adventure/uncertain.

Try cleaning the RAM contacts with a clean pencil eraser. Hopefully that
would take care of it. Don't use other cleaners until you try the eraser
trick first. As this one seems to last the longest.