I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

On Sun, 23 Nov 2008 22:38:50 +0000, Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

It's a pressure relief thing. If the electrolyte overheats and boils,
the slits crack and a more explosive event is avoided.

John

On Sun, 23 Nov 2008 22:38:50 +0000, Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

To let the magic smoke out away from other components ?:-)

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona 85048 Skype: Contacts Only | |
| Voice480)460-2350 Fax: Available upon request | Brass Rat |
| E-mail Icon at http://www.analog-innovations.com | 1962 |

I love to cook with wine Sometimes I even put it in the food

"Meee"

I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.


** You had better replace those FAULTY caps as soon as possible.

Do not use the PC until you have, as other parts may become damaged.

http://en.wikipedia.org/wiki/Capacitor_plague



...... Phil

On Sun, 23 Nov 2008 14:42:25 -0800, John Larkin
wrote:

On Sun, 23 Nov 2008 22:38:50 +0000, Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

It's a pressure relief thing. If the electrolyte overheats and boils,
the slits crack and a more explosive event is avoided.

John


I would add that all those he saw that were split are likely no longer
at their manufactured value.

Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).


The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

You will find a lot of info here.
http://badcaps.net/
http://en.wikipedia.org/wiki/Capacitor_plague

Graham

cross-posted to sci.electronics repair for info

Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).


The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

You will find a lot of info here.
http://badcaps.net/
http://en.wikipedia.org/wiki/Capacitor_plague

Graham

cross-posted to sci.electronics repair for info

Eeyore wrote:

Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).

The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

That is REPLACE ALL OF THEM, NOT JUST ONES THAT HAVE BLOWN TODAY


You will find a lot of info here.
http://badcaps.net/
http://en.wikipedia.org/wiki/Capacitor_plague

Nice quip from the above

" From so many users, ranging from large corporate networks all the way
to the home user, the number one reason people give for wanting to
repair their hardware is they want to avoid a new system and the
disaster known as Windows Vista!

On a humorous note regarding Vista, I spoke to an IT guy who manages a
small business network for an insurance company (maintains a 100
terminal network), and had a bunch of failing Dell SX280's, which I
repaired. One branch had the brilliant idea to "upgrade" to Vista
systems, and his job was to make them all play nice with each other.
This gentleman was probably the most professional, polite, and courteous
clients I've ever spoken with on the phone, until we got onto the
subject of Vista....then the four-letter words started flowing
freely... In the end, he wiped all the Vista machines, and upgraded
them back to XP Pro."

Graham

Eeyore wrote:

Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).

The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

That is REPLACE ALL OF THEM, NOT JUST ONES THAT HAVE BLOWN TODAY


You will find a lot of info here.
http://badcaps.net/
http://en.wikipedia.org/wiki/Capacitor_plague

Nice quip from the above

" From so many users, ranging from large corporate networks all the way
to the home user, the number one reason people give for wanting to
repair their hardware is they want to avoid a new system and the
disaster known as Windows Vista!

On a humorous note regarding Vista, I spoke to an IT guy who manages a
small business network for an insurance company (maintains a 100
terminal network), and had a bunch of failing Dell SX280's, which I
repaired. One branch had the brilliant idea to "upgrade" to Vista
systems, and his job was to make them all play nice with each other.
This gentleman was probably the most professional, polite, and courteous
clients I've ever spoken with on the phone, until we got onto the
subject of Vista....then the four-letter words started flowing
freely... In the end, he wiped all the Vista machines, and upgraded
them back to XP Pro."

Graham

Archimedes' Lever wrote:

John Larkin wrote:
On Sun, 23 Nov 2008 22:38:50 +0000, Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

It's a pressure relief thing. If the electrolyte overheats and boils,
the slits crack and a more explosive event is avoided.

I would add that all those he saw that were split are likely no longer
at their manufactured value.

Especially with all the electrolyte evaporated ! Even without splits, I've
seen examples where the capacitance had dropped to ~ 10% of original value.

This can cause regulators to 'hunt' and blow the CPU by over-volting it.

Certain mobo makers - Gigabyte ? - now use only 'organic' type electros for
reliability.

Graham

"Eeyore" wrote in message
...


Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).


The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.

Arfa



You will find a lot of info here.
http://badcaps.net/
http://en.wikipedia.org/wiki/Capacitor_plague

Graham

cross-posted to sci.electronics repair for info

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.


You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

f825_677 wrote:

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.

You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

If you know the IC's buggered (or even of low commercial value), cut every pin
and remove them individually. Then clean the holes up. It always wins on time and
cost.

Graham

On Sun, 23 Nov 2008 22:38:50 +0000, Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Love posters who answer their own question!

Arfa Daily wrote:

"Eeyore" wrote
Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).

The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.

True. They don't exactly go overboard on the drill diameter !

Graham

"Arfa Daily" wrote in message
...

"Eeyore" wrote in message
...


Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.

To release the pressure and gunk under fault conditions (or bad
manufacture).


The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a
board, that you will *ever* come across. And then some.

Arfa


They certainly can be difficult, an absolute must is an iron with sufficient
power to heat the joint through quickly (DO NOT use one of those soldering
guns that passes low voltage/high current through a solid copper element -
they induce destructive currents in the PCB traces!).

Usually the 2 wires can be eased out by tilting the capacitor as one of the
solder joints is melted and then the other until its out.

Clearing the holes also isn't easy, solder wick won't do it you need a
solder sucker and a lot of practice getting enough of the iron tip on the
tinned pad and still leave enough gap to suck the solder through - you will
probably have to go at it from both sides too!

Once or twice out of sheer desperation I've heated the through hole and
swatted the board on the edge of the bench to knock the solder out, but this
has a real risk of breaking any crystals on the board!

"Eeyore" wrote in message
...


f825_677 wrote:

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle
to
do the job. These are some of the very worst bitches to get out of a
board,
that you will *ever* come across. And then some.

You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

If you know the IC's buggered (or even of low commercial value), cut every
pin
and remove them individually. Then clean the holes up. It always wins on
time and
cost.

Graham


If you make sure none of the pins are bent on the solder side sometimes its
possible to just lift the pins out one by one on the tip of the iron, if the
pin is sheared off close to the IC body it leaves a slight hook on top,
simply hook the tip of the iron under it and add fresh solder - this runs
down the pin providing heat transfer to the solder joint and the surface
tension holds the pin on the tip as you lift it out of the hole.

"Eeyore" wrote in message

f825_677 wrote:

You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..

If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.

Isn't that a PGA? Hard to cut the pins.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

Eeyore wrote:

f825_677 wrote:

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.
You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

If you know the IC's buggered (or even of low commercial value), cut every pin
and remove them individually. Then clean the holes up. It always wins on time and
cost.

Graham


sadly that is not an option, the device is a constructed ceramic case of other devices
within with the pins on the underside of the case - rather like a BGA device but pins and
not blobs if you understand what I mean. The board has an exchange value with Sony of
£1050 and they will only accept a board for exchange if not physically damaged, so being
careful and taking time is the only option..

ian field wrote:
"Eeyore" wrote in message
...

f825_677 wrote:

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle
to
do the job. These are some of the very worst bitches to get out of a
board,
that you will *ever* come across. And then some.
You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..
If you know the IC's buggered (or even of low commercial value), cut every
pin
and remove them individually. Then clean the holes up. It always wins on
time and
cost.

Graham


If you make sure none of the pins are bent on the solder side sometimes its
possible to just lift the pins out one by one on the tip of the iron, if the
pin is sheared off close to the IC body it leaves a slight hook on top,
simply hook the tip of the iron under it and add fresh solder - this runs
down the pin providing heat transfer to the solder joint and the surface
tension holds the pin on the tip as you lift it out of the hole.



Yes I've employed that method on convential type devices - but the device I describe is
somewhat different - have a look at the datasheet you'll see what I mean.
Its a 41 pin device about an inch square - all pins on the underside

Tom Del Rosso wrote:
"Eeyore" wrote in message

f825_677 wrote:
You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..
If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.

Isn't that a PGA? Hard to cut the pins.


Yes it is - and you're right.

ian field wrote:
"Arfa Daily" wrote in message
...
"Eeyore" wrote in message
...

Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them.
To release the pressure and gunk under fault conditions (or bad
manufacture).


The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.
Oh dear.

A: How old is it ? (from date of manufacture)

B: Can you read what brands they are ?

C: Has your PC sharted behaving strangely yet ?

D: What brand mobo is it ?

E: Replace ASAP with well-known brand, low ESR (switching) types.
As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a
board, that you will *ever* come across. And then some.

Arfa


They certainly can be difficult, an absolute must is an iron with sufficient
power to heat the joint through quickly (DO NOT use one of those soldering
guns that passes low voltage/high current through a solid copper element -
they induce destructive currents in the PCB traces!).

Usually the 2 wires can be eased out by tilting the capacitor as one of the
solder joints is melted and then the other until its out.

Clearing the holes also isn't easy, solder wick won't do it you need a
solder sucker and a lot of practice getting enough of the iron tip on the
tinned pad and still leave enough gap to suck the solder through - you will
probably have to go at it from both sides too!

Once or twice out of sheer desperation I've heated the through hole and
swatted the board on the edge of the bench to knock the solder out, but this
has a real risk of breaking any crystals on the board!


Good soldering is a skill - and to be practiced as often as possible if you don't want
your work to look like a flock of seagulls have flown over

ian field wrote:

"Eeyore" wrote
f825_677 wrote:
Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle
to do the job. These are some of the very worst bitches to get out of a
board, that you will *ever* come across. And then some.

You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

If you know the IC's buggered (or even of low commercial value), cut every
pin and remove them individually. Then clean the holes up. It always wins on

time and cost.

If you make sure none of the pins are bent on the solder side sometimes its
possible to just lift the pins out one by one on the tip of the iron, if the
pin is sheared off close to the IC body it leaves a slight hook on top,
simply hook the tip of the iron under it and add fresh solder - this runs
down the pin providing heat transfer to the solder joint and the surface
tension holds the pin on the tip as you lift it out of the hole.

Goes to show what a range of real skills the true repairman needs. And yes I've
done it too. A magnetic Weller TCP tip and a pin containing steel helps !

Graham

Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:

You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..

If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.

Isn't that a PGA? Hard to cut the pins.

Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

Graham

On Mon, 24 Nov 2008 10:28:13 +0000, f825_677
wrote:

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.


You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..


Desoldering a through hole part on a multi-layer PCB can be difficult,
especially if the part in question or the PCB is sinking all of your
solder tip heat away.

I have two good solutions. First one is to pre-heat the entire PCB
assembly to about 160F. That will keep the heat from sinking away so
much.

You can also heat the local area with a heat gun. This works even
better with the pre-heated PCB. The soldering operations generally take
place without a hitch in these cases.

On Mon, 24 Nov 2008 11:18:33 +0000, Eeyore
wrote:



f825_677 wrote:

Arfa Daily wrote:

As Graham says, but be aware that unless you are a *very* experienced
solderer, and posess the right desoldering equipment, you will struggle to
do the job. These are some of the very worst bitches to get out of a board,
that you will *ever* come across. And then some.

You should try a Sony 1602 or 1601 IC from one of their broadcast mixer
boards - it can take an hour if you're lucky and all day if you're not
and we have professionaly desoldering vacumme equipment - the holes are
barely larger than the pin its self every engineer working on these
things in every broadcast engineering department complaints about these
devices.. Give me a 100 pin BGA device any day..

If you know the IC's buggered (or even of low commercial value), cut every pin
and remove them individually. Then clean the holes up. It always wins on time and
cost.

Graham



Absolutely. If the part being removed is not part of the salvage
operation, cut all pins, remove the part, and then desolder each pin
individually. You could also fill the open holes with solder, and
dog-ear the new chip's pins outward and make it a surface mount install.

On Mon, 24 Nov 2008 23:01:01 +0000, Eeyore
wrote:



Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:

You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..

If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.

Isn't that a PGA? Hard to cut the pins.

Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

If it is a ceramic package, that is not far from the best way to remove
it.

I would: Heat the PCB up a couple hundred degrees F, then heat the
ceramic chip package body up with a high temp heat gun, while inverted.
A heat gun on the bottom of the board should cause a near instant reflow,
and release of the chip.

The chip and pins get real hot. The PCB assembly only gets hot enough
to perform the reflow/release operation.

Archimedes' Lever wrote:
On Mon, 24 Nov 2008 23:01:01 +0000, Eeyore
wrote:


Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:
You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..
If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.
Isn't that a PGA? Hard to cut the pins.
Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

If it is a ceramic package, that is not far from the best way to remove
it.

I would: Heat the PCB up a couple hundred degrees F, then heat the
ceramic chip package body up with a high temp heat gun, while inverted.
A heat gun on the bottom of the board should cause a near instant reflow,
and release of the chip.


And all the other SMT devices will fall off the board as well - would right off the board
its a £1050 exchange PCB from Sony, but to buy new is £11,600, the whole mixer at purchase
was just over £300,000 its not a cheap piece of equipment, but then a lot of broadcast kit
is expensive and needs special knowledge to be worked on.

I saw one of our junior engineers employ your method - I prefer my guys to use time and
patience over speed and probable damage.

"f825_677" wrote in message
...
Archimedes' Lever wrote:
On Mon, 24 Nov 2008 23:01:01 +0000, Eeyore
wrote:


Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:
You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..
If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.
Isn't that a PGA? Hard to cut the pins.
Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

If it is a ceramic package, that is not far from the best way to remove
it.

I would: Heat the PCB up a couple hundred degrees F, then heat the
ceramic chip package body up with a high temp heat gun, while inverted.
A heat gun on the bottom of the board should cause a near instant reflow,
and release of the chip.


And all the other SMT devices will fall off the board as well - would
right off the board its a £1050 exchange PCB from Sony, but to buy new is
£11,600, the whole mixer at purchase was just over £300,000 its not a
cheap piece of equipment, but then a lot of broadcast kit is expensive and
needs special knowledge to be worked on.

I saw one of our junior engineers employ your method - I prefer my guys to
use time and patience over speed and probable damage.

Most electronics tool suppliers stock pencil blowlamps which would be
precise enough to desolder a decent size ceramic chip, some are sold in sets
with a variety of nozzle attachments. The spread is way more precise than a
heat gun.

For smaller chips it might be worth looking out for one of those "windproof"
lighters that uses the same design of jet as the pencil blowlamp - only
smaller.

"flipper" wrote in message
...
On Mon, 24 Nov 2008 09:29:23 -0500, PeterD wrote:

On Sun, 23 Nov 2008 22:38:50 +0000, Meee wrote:

I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.

Love posters who answer their own question!

It seems obvious to those who know but I'd be wiling to bet he
wondered why they made it 'weak' with the indentations so that it
'broke' when it otherwise wouldn't have.

Not too sure about the "otherwise wouldn't have" - without those
indentations it would likely have burst with a fairly impressive bang.

"ian field" wrote in message


Most electronics tool suppliers stock pencil blowlamps which would be
precise enough to desolder a decent size ceramic chip, some are sold
in sets with a variety of nozzle attachments. The spread is way more
precise than a heat gun.

I think he's saying that you can't apply heat to the component side at all,
even if it's directed only at the target device, because the package in
question is a hybrid with SMT parts exposed on its own surface.


For smaller chips it might be worth looking out for one of those
"windproof" lighters that uses the same design of jet as the pencil
blowlamp - only smaller.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

"Tom Del Rosso" wrote in message
...

"ian field" wrote in message


Most electronics tool suppliers stock pencil blowlamps which would be
precise enough to desolder a decent size ceramic chip, some are sold
in sets with a variety of nozzle attachments. The spread is way more
precise than a heat gun.

I think he's saying that you can't apply heat to the component side at
all,
even if it's directed only at the target device, because the package in
question is a hybrid with SMT parts exposed on its own surface.


If its going in the bin once removed, that hardly matters.

"f825_677" wrote in message
...


And all the other SMT devices will fall off the board as well - would
right off the board its a £1050 exchange PCB from Sony, but to buy new is
£11,600, the whole mixer at purchase was just over £300,000 its not a
cheap piece of equipment, but then a lot of broadcast kit is expensive and
needs special knowledge to be worked on.

I saw one of our junior engineers employ your method - I prefer my guys to
use time and patience over speed and probable damage.

have you seen http://www.oxygendct.com/acatalog/OxyChip_ICs.html ?

Best Regards

Steve sousa

On Tue, 25 Nov 2008 10:38:45 +0000, f825_677
wrote:

Archimedes' Lever wrote:
On Mon, 24 Nov 2008 23:01:01 +0000, Eeyore
wrote:


Tom Del Rosso wrote:

"Eeyore" wrote in message
f825_677 wrote:
You should try a Sony 1602 or 1601 IC from one of their broadcast
mixer boards - it can take an hour if you're lucky and all day if
you're not and we have professionaly desoldering vacumme equipment
- the holes are barely larger than the pin its self every engineer
working on these things in every broadcast engineering department
complaints about these devices.. Give me a 100 pin BGA device any
day..
If you know the IC's buggered (or even of low commercial value), cut
every pin and remove them individually. Then clean the holes up. It
always wins on time and cost.
Isn't that a PGA? Hard to cut the pins.
Is it ? I was referring to pinned ICs. Use a flame thrower on a PGA
! ;-)

If it is a ceramic package, that is not far from the best way to remove
it.

I would: Heat the PCB up a couple hundred degrees F, then heat the
ceramic chip package body up with a high temp heat gun, while inverted.
A heat gun on the bottom of the board should cause a near instant reflow,
and release of the chip.


And all the other SMT devices will fall off the board as well

WRONG!

A 150 degree F assembly is NOT at solder reflow temperature.

- would right off the board

WRONG! You PRE-heat the PCB. You only heat to reflow temp, the IC
chip you are removing. D'OH!

its a £1050 exchange PCB from Sony, but to buy new is £11,600, the whole mixer at purchase
was just over £300,000 its not a cheap piece of equipment,

Yeah, and you are not very brainy to think that someone would tell you
to reflow the entire board. Learn to read. Then learn how to properly
comprehend what you read.

but then a lot of broadcast kit
is expensive and needs special knowledge to be worked on.

No. It needs a proper technician. Nothing special about that. Just
educated.

I worked at General Instrument. I know about racks that cost $2M each,
and the broadcast industry had to buy our gear.

I saw one of our junior engineers employ your method

No, you didn't. Obviously, since you have a bent ****ing perception of
what "my method" is.

- I prefer my guys to use time and
patience over speed and probable damage.

You're a goddamned presumptuous idiot. The method I described IS how
one removes a part from a board. You need to learn about heat sources
and sinking. In the case I described, the heat is applied to the IC
chip. So, what gets damaged?

ian field wrote:

If its going in the bin once removed, that hardly matters.

I heard a story (likely true) of an MD who went round the factory after
'time', pulling components back out of the bin and replacing them on the
bench.

Graham

"Archimedes' Lever" wrote in message

On Tue, 25 Nov 2008 10:38:45 +0000, f825_677
wrote:

its a £1050 exchange PCB from Sony, but to buy new is £11,600, the
whole mixer at purchase was just over £300,000 its not a cheap piece
of equipment,

Yeah, and you are not very brainy to think that someone would tell
you to reflow the entire board. Learn to read. Then learn how to
properly comprehend what you read.

You refer to "the entire board". He refers to a PCB, but not the one you
think. The part in question is a PCB in itself. It's a hybrid module with
its own SMT parts, so you can't heat the whole part.

Google the part number and see what it looks like.


--

Reply in group, but if emailing add one more
zero, and remove the last word.

"Eeyore" wrote in message
...


ian field wrote:

If its going in the bin once removed, that hardly matters.

I heard a story (likely true) of an MD who went round the factory after
'time', pulling components back out of the bin and replacing them on the
bench.

Graham



The stupidest suits tend to float to the top!

ian field wrote:

"Eeyore" wrote
ian field wrote:

If its going in the bin once removed, that hardly matters.

I heard a story (likely true) of an MD who went round the factory after
'time', pulling components back out of the bin and replacing them on the
bench.

The stupidest suits tend to float to the top!

He also bought cheap thousands of TL072s that been salt-water contamined on a
sea voyage IIRC.

You can imagine what that did to the returns rate !

Graham

On Mon, 24 Nov 2008 10:27:59 +1100, "Phil Allison"
wrote:


"Meee"

I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.


** You had better replace those FAULTY caps as soon as possible.

Do not use the PC until you have, as other parts may become damaged.

http://en.wikipedia.org/wiki/Capacitor_plague



..... Phil


My PC shutdown the otherday from overttemp. Opened up for a look,
reason for OT was dust. Sucked it all up and she is up an running
again. Did notice the electro's were stuffed, thought about replacing
them but could not be stuffed. Need a shop that does it for you, need
on in Brissie.

Prevents dangerous explosions when the Cap breaks down, the indents weakens
the housing to allow for pressure to be released thus preventing a build up
and explosion. Very good idea. You need to replace and figure out why
yours failed.

DRLee

"Meee" wrote in message
...
I was wondering why vertical mounting electrolytics have like an
indented cross on them. The reason I ask is because there's 4 largeish
one around my CPU on the motherboard and they have all split open,
along the indentations.