one last dead system question

[Chris]

Thanks for the help so far, I am going to replace the caps with the
lower rated caps (1200uf vs 1800uf). Somone posted that replacing
caps on multi-layer boards was very difficult. The 3 caps that caps
that need replacement go all the way through the board and are
soldered on the back of the board. I am assuming that I can just
de-solder the old caps are solder on the new caps without a hitch. My
soldering skills are so-so, but I have soldered and desoldered chips
from old boards before. For example, I replaced the bios chip from an
Atari 7800 system board with a new bios chip to make a cart dumper.
Any advise? Would this be beyond my skill level?

Chris
If life seems jolly rotten
There's spmething you've forgotten
and thats to laugh and smile and dance and sing!

 

[krw]

Thanks for the help so far, I am going to replace the caps with the
lower rated caps (1200uf vs 1800uf). Somone posted that replacing
caps on multi-layer boards was very difficult. The 3 caps that caps
that need replacement go all the way through the board and are
soldered on the back of the board. I am assuming that I can just
de-solder the old caps are solder on the new caps without a hitch. My
soldering skills are so-so, but I have soldered and desoldered chips
from old boards before. For example, I replaced the bios chip from an
Atari 7800 system board with a new bios chip to make a cart dumper.
Any advise? Would this be beyond my skill level?

If you've desoldered a BIOS chip successfully you should be
alright. Remember that the cap leads are heavier and they are
connected directly to planes (a big heat sink) and will take more
heat. Too much though and bad things happen. I'd highly recommend
"solder wick" ( essentially tinned copper braid laced with flux) to
remove the caps and clean the pads.

Let's put it this way, what have you got to lose?

 

[Arno Wagner]

Thanks for the help so far, I am going to replace the caps with the
lower rated caps (1200uf vs 1800uf).

Good luck! I had a board going into oscillations when I tried
that. May blow up your CPU.

Somone posted that replacing
caps on multi-layer boards was very difficult. The 3 caps that caps
that need replacement go all the way through the board and are
soldered on the back of the board. I am assuming that I can just
de-solder the old caps are solder on the new caps without a hitch. My
soldering skills are so-so, but I have soldered and desoldered chips
from old boards before. For example, I replaced the bios chip from an
Atari 7800 system board with a new bios chip to make a cart dumper.
Any advise? Would this be beyond my skill level?

De-soldering should work. Re-soldering also. The trick is clearing the
holes in-between, which can be very hard, except with the right equipment.
On thing you can do is drill them out. For this it is very important to
use a drill bit that is at leat 0.1mm (better 0.2mm) smaller in diameter
than the holes.

Best is to measure the leads of the old or new caps and make the drill bit
0.1mm thicker. If your drill bit is smaller than the holes and you drill
carefully (Dremel or the like on very slow setting), you will not damage
the copper much, since the tin solder is much softer. I have done this
several times sucessfully.

Arno

 

[Arno Wagner]

If you've desoldered a BIOS chip successfully you should be
alright. Remember that the cap leads are heavier and they are
connected directly to planes (a big heat sink) and will take more
heat.

And the Atari had dual or 3-layer PCB, while a modern mainboard can
have up to 7...

Too much though and bad things happen. I'd highly recommend
"solder wick" ( essentially tinned copper braid laced with flux) to
remove the caps and clean the pads.

Forget it. You will not get the caps desoldered, unless you set your
soldering iron to 450C or so, and then you run a real risk
of damaging the board. I tried this with a professional vaccuum
desoldering station and it worked maybe one time out of three.
solder wick will not work at all.

Use additional solder to get clean contact between the soldering iron
and the board, melt the solder quickly and carefully lever the cap out
on that side. Repeat on the oder side. After all they only have two
leads, so this works. You will end up witk a clogged though hole, see
my other posting on how to deal with that.

Let's put it this way, what have you got to lose?

A board, that is essentially fine?

Arno

 

[krw]

And the Atari had dual or 3-layer PCB, while a modern mainboard can
have up to 7...

The number of planes is irrelevant. Each lead of the cap is only
connected to one.

Forget it. You will not get the caps desoldered, unless you set your
soldering iron to 450C or so, and then you run a real risk
of damaging the board. I tried this with a professional vaccuum
desoldering station and it worked maybe one time out of three.
solder wick will not work at all.

I'm so glad *you* are the font of all knowledge. I've been doing
this sort of thing a *LONG* time. Solder wick works.

Use additional solder to get clean contact between the soldering iron
and the board, melt the solder quickly and carefully lever the cap out
on that side. Repeat on the oder side. After all they only have two
leads, so this works. You will end up witk a clogged though hole, see
my other posting on how to deal with that.

Doing that you're likely to lift the pads. Bad plan.

A board, that is essentially fine?

What a maroon!

 

[krw]

Good luck! I had a board going into oscillations when I tried
that. May blow up your CPU.


De-soldering should work. Re-soldering also. The trick is clearing the
holes in-between, which can be very hard, except with the right equipment.
On thing you can do is drill them out. For this it is very important to
use a drill bit that is at leat 0.1mm (better 0.2mm) smaller in diameter
than the holes.

Bullshit. Just heat a hunk of capacitor or resistor lead of
similar size and pass it through the hole.

Best is to measure the leads of the old or new caps and make the drill bit
0.1mm thicker. If your drill bit is smaller than the holes and you drill
carefully (Dremel or the like on very slow setting), you will not damage
the copper much, since the tin solder is much softer. I have done this
several times sucessfully.

Oh, this is a good idea! What happens when you destroy the plated-
through hole?

 

[Arno Wagner]

The number of planes is irrelevant. Each lead of the cap is only
connected to one.

For the powrer parts that is untrue. They may be connected to
several layers. All I have seen were connected to at least two.

I'm so glad *you* are the font of all knowledge. I've been doing
this sort of thing a *LONG* time. Solder wick works.

I have been doing this for more than two decades. Solder wick may
work for you or me, but not for somebode with the soldering skills
of the OP. And it especially deos not work if you have a large copper
area on the upper side of the board around the trough-hole.

Doing that you're likely to lift the pads. Bad plan.

Very unlikely. Even with excessive force you are more likely
to rip the leads out of the capacitor. But there is no need to
use excessive force. The trhoug-connections of power leads
are pretty sturdy in these boards.

What a maroon!

And the same back to you. Seems to me you just disqualified yourself
for any further discussion...

Arno

 

[Arno Wagner]

Bullshit. Just heat a hunk of capacitor or resistor lead of
similar size and pass it through the hole.

Good luck with that amateur-style technique...

Oh, this is a good idea! What happens when you destroy the plated-
through hole?

You don't. Unless you are really clumsy.

Arno

 

[krw]

For the powrer parts that is untrue. They may be connected to
several layers. All I have seen were connected to at least two.



I have been doing this for more than two decades.

Add one, and change.

Solder wick may
work for you or me, but not for somebode with the soldering skills
of the OP. And it especially deos not work if you have a large copper
area on the upper side of the board around the trough-hole.



Very unlikely. Even with excessive force you are more likely
to rip the leads out of the capacitor. But there is no need to
use excessive force. The trhoug-connections of power leads
are pretty sturdy in these boards.



And the same back to you. Seems to me you just disqualified yourself
for any further discussion...

Do come back when you've knocked that pointy chip off your
shoulders. On second thought...

 

[krw]

Good luck with that amateur-style technique...

Weren't you just talking about a technique that might work for a
has-been-drip-under-pressure, but an amateur better not try? <LOL>

It's a *lot* safer than a drill bit!

You don't. Unless you are really clumsy.

You don't because if your's smart you don't drill out a plated
through hole at all! Sheesh!

 

[George Macdonald]

Thanks for the help so far, I am going to replace the caps with the
lower rated caps (1200uf vs 1800uf). Somone posted that replacing
caps on multi-layer boards was very difficult. The 3 caps that caps
that need replacement go all the way through the board and are
soldered on the back of the board. I am assuming that I can just
de-solder the old caps are solder on the new caps without a hitch. My
soldering skills are so-so, but I have soldered and desoldered chips
from old boards before. For example, I replaced the bios chip from an
Atari 7800 system board with a new bios chip to make a cart dumper.
Any advise? Would this be beyond my skill level?

I think you need to do a little more investigation here: read the BadCaps
Web site in some detail; figure out the mfr of the bad ones and the mfr of
the ones you intend to use as replacements. There's no point in replacing
just three if the others are also by the same mfr - read the whole story on
this at http://www.niccomp.com/taiwanlowesr.htm and you'll see that it's a
problem with the aqueous electrolyte which lacks an inhibitor for gassing
of the electrolyte. IOW if three are bad they're all bad and failure is
only a matter of time. Have you checked the bases of the other,
non-bulging, caps for leakage.

As for soldering, I've also replaced a BIOS chip on a mbrd, with a socket
in fact, but the area of the mbrd where the chip was placed meant that
there was a low chance of err, peripheral damage to neighboring components
and traces. I think the caps are worth a try but I'm not sure I'd get the
job done right myself. Do you already have the right tools?... just the
right solder iron power and type which I'm not sure of - somebody? I think
in your situation I'd get the wick *and* a good sucker tool (Paladin) and
start with the wick with maybe the sucker for clean-up.

 

[Rthoreau]

On Wed, 22 Nov 2006 15:37:23 GMT, Chris

<snip>
As for soldering, I've also replaced a BIOS chip on a mbrd, with a socket
in fact, but the area of the mbrd where the chip was placed meant that
there was a low chance of err, peripheral damage to neighboring components
and traces. I think the caps are worth a try but I'm not sure I'd get the
job done right myself. Do you already have the right tools?... just the
right solder iron power and type which I'm not sure of - somebody? I think
in your situation I'd get the wick *and* a good sucker tool (Paladin) and
start with the wick with maybe the sucker for clean-up.

Well doesn't that defeat the purpose of DIY, it sounds like the tools
to do the job will cost more than the cost of a new board. I can
understand the purpose of learning how to do it, but it almost sounds
like the learning curve is too much if the board is used for production
use, or a use with some degree of realibility.

I guess the next question would be is what is the going rate to send it
to a dedicated place that does this kind of work. Also what would the
manufacture charge if they did the recapping of the board? I bet if you
talked to the right folks, you might get a really good deal, heck you
might even get a free board if your a loyal customer. If it was me I
would send the board with the new caps to anyone on this group who said
they could do it, just to see if they could repair it. Yeah I know it's
probably cheaper to just go get a new board, then to pay the freight,
not to mention the fact that you know it's not dodgy. Even if you fixed
the caps, what happens if some of the traces were damaged by the
spillage of the broken caps.

This kinda of goes with the the reasoning that never offer to reinstall
an OS on a friends computer. It's just not worth the headache, as
people will complain, and wine that widget xyz seems to be broken or
that you did not save the most recent bookmark to that superdupper
review. But heck if I had a some busted caps, I would do it just for
the humor value of it.

Rthoreau

 

[Franc Zabkar]

I guess the next question would be is what is the going rate to send it
to a dedicated place that does this kind of work.

Take it to a workshop that solders and desolders components for a
living, eg a TV/VCR/audio repair shop.

- Franc Zabkar

 

[George Macdonald]

Well doesn't that defeat the purpose of DIY, it sounds like the tools
to do the job will cost more than the cost of a new board. I can
understand the purpose of learning how to do it, but it almost sounds
like the learning curve is too much if the board is used for production
use, or a use with some degree of realibility.

Depends how you look at it. I have moderate soldring skills and I *would*
tackle this... and may have to if I read the umm, incipient bulges right.
You don't need a (de-)soldering station and even if you did they're not
that expensive; if you already have say a 40W iron it would probably do the
job; if you need to buy a 60W, which might be necessary for some mbrds with
localized high heat capacitance around the caps, even a Weller 60W is
nickels & dimes... same for a Paladin vacuum pump. If you're into DIY
system building those are tools which you probably should have as part of
your "kit" anyway.

You accumulate tools as you need over the years - and sometimes when you
don't "need" it's often somebody's great idea for a present, example:
Dremel tool. Mine is practically worn out now but it's not something I
would have thought indispensable enough to go to my holster for the plastic
at the time. Among the assortment of tools I have lying around, I also
have a pop-rivet kit which I've used maybe 3 times in 20 years or so, but
when I needed it nothing else would do. Umm, every handyman should have a
soldering iron of some sort - no?

I guess the next question would be is what is the going rate to send it
to a dedicated place that does this kind of work. Also what would the
manufacture charge if they did the recapping of the board? I bet if you
talked to the right folks, you might get a really good deal, heck you
might even get a free board if your a loyal customer. If it was me I
would send the board with the new caps to anyone on this group who said
they could do it, just to see if they could repair it. Yeah I know it's
probably cheaper to just go get a new board, then to pay the freight,
not to mention the fact that you know it's not dodgy. Even if you fixed
the caps, what happens if some of the traces were damaged by the
spillage of the broken caps.

Easy to look up -- www.badcaps.net & www.motherboardrepair.com -- and it
seems like the price is about $50. including return shipping. If you're
not into DIY, the Dell & Gateway "bad cap experience" was painful for the
early err, adopters/victims but much easier for the later ones, though I
gather there were some who were left out in the cold by even Dell after it
'fessed up - http://www.poweredgeforums.com/showthread.php?t=2236.

This kinda of goes with the the reasoning that never offer to reinstall
an OS on a friends computer. It's just not worth the headache, as
people will complain, and wine that widget xyz seems to be broken or
that you did not save the most recent bookmark to that superdupper
review. But heck if I had a some busted caps, I would do it just for
the humor value of it.

Glad to see you appreciate the dilemma of helping friends... voice of
experience it appears. IME it's works this way: you're not supposed to
denigrate the "friend" by doing the job right; yer supposed to fix it after
it's broken!

Reminds me of a "friend" who bought a scanner back in the Win98 days: he
talked to me for installation advice on the phone - I told him you *must*
install the software first; his genius f**kin' SIL comes along and says "Oh
it's plug 'n' play, nah you just plug it in and it gets recognized...
*then* you install the software". Obviously this guy "knew" all the latest
"stuff"... what a mess!

 

[Arno Wagner]

Well doesn't that defeat the purpose of DIY, it sounds like the tools
to do the job will cost more than the cost of a new board. I can
understand the purpose of learning how to do it, but it almost sounds
like the learning curve is too much if the board is used for production
use, or a use with some degree of realibility.

[/QUOTE]

Depends how you look at it. I have moderate soldring skills and I *would*
tackle this... and may have to if I read the umm, incipient bulges right.
You don't need a (de-)soldering station

In fact I found a de-soldering station of limited usefulness...

and even if you did they're not
that expensive; if you already have say a 40W iron it would probably do the
job; if you need to buy a 60W, which might be necessary for some mbrds with
localized high heat capacitance around the caps, even a Weller 60W is
nickels & dimes... same for a Paladin vacuum pump. If you're into DIY
system building those are tools which you probably should have as part of
your "kit" anyway.

You accumulate tools as you need over the years - and sometimes when you
don't "need" it's often somebody's great idea for a present, example:
Dremel tool. Mine is practically worn out now but it's not something I
would have thought indispensable enough to go to my holster for the plastic
at the time. Among the assortment of tools I have lying around, I also
have a pop-rivet kit which I've used maybe 3 times in 20 years or so, but
when I needed it nothing else would do. Umm, every handyman should have a
soldering iron of some sort - no?

Yes, definitely.

Easy to look up -- www.badcaps.net & www.motherboardrepair.com -- and it
seems like the price is about $50. including return shipping. If you're
not into DIY, the Dell & Gateway "bad cap experience" was painful for the
early err, adopters/victims but much easier for the later ones, though I
gather there were some who were left out in the cold by even Dell after it
'fessed up - http://www.poweredgeforums.com/showthread.php?t=2236.

Glad to see you appreciate the dilemma of helping friends... voice of
experience it appears. IME it's works this way: you're not supposed to
denigrate the "friend" by doing the job right; yer supposed to fix it after
it's broken!

True. Otherwise the friend does not have a chance to learn...

Reminds me of a "friend" who bought a scanner back in the Win98 days: he
talked to me for installation advice on the phone - I told him you *must*
install the software first; his genius f**kin' SIL comes along and says "Oh
it's plug 'n' play, nah you just plug it in and it gets recognized...
*then* you install the software". Obviously this guy "knew" all the latest
"stuff"... what a mess!

Half-knowledge is worse than no knowledge....

Arno

 

[George Macdonald]

Take it to a workshop that solders and desolders components for a
living, eg a TV/VCR/audio repair shop.

Are you sure about that Franc? I thought all that most of those guys do
now is unplug and re-plug modules? Who in their right mind is going to pay
to repair a VCR?

 

[Franc Zabkar]

Are you sure about that Franc?

I once worked in such a place. These shops employ *real* technicians,
not just trained (or untrained) monkeys who can turn a Phillips head
screwdriver.

I thought all that most of those guys do now is unplug and re-plug modules?

No, they do *real* component level repair. Just take the back off your
CRT TV and tell me how many "modules" you can see. You'll probably
only find one PCB.

The newer plasma and LCD TVs are a different story, though.

Who in their right mind is going to pay to repair a VCR?

Today, probably nobody, unless they have an investment in tapes, and
have a quality machine. I certainly wouldn't pay someone to repair any
of the current crop of VCRs.

Anyway, a standard VCR service involves a video belt/tyre kit, tension
band, brake pads, pinch roller, mode switch, cleaning of video head
and tape path, gear and rail lube. For the sorts of components that
break in a typical VCR, see section 4 of this catalogue:

http://www.wagner.net.au/Sections/

- Franc Zabkar

 

[George Macdonald]

I once worked in such a place. These shops employ *real* technicians,
not just trained (or untrained) monkeys who can turn a Phillips head
screwdriver.


No, they do *real* component level repair. Just take the back off your
CRT TV and tell me how many "modules" you can see. You'll probably
only find one PCB.

I haven't looked in a while. In a VCR I opened up a few years ago, the
tuner, FM modulator, control panel and drum drive circuit were modules
IIRC.

The newer plasma and LCD TVs are a different story, though.


Today, probably nobody, unless they have an investment in tapes, and
have a quality machine. I certainly wouldn't pay someone to repair any
of the current crop of VCRs.

Just my situation. I had the misfortune, a few years ago, to get a Sony
SLV-998HF -- not the highest "end" but it has flying head editing and was
fairly expensive -- when my really old Hitachi "high-end" came back from a
visit to the "shop" with a new problem. The Sony's FM modulator went bad
in the first few months, which didn't bother me too much since I didn't use
it. Now the tuner has gone bad and I'm more tempted to take my rage out on
it than fix it.

Let me ask you: is it possible that a (Motorola) STB might blow the tuner
on a VCR/TV? The Sony VCR's tuner went gaga a few weeks after we got a new
cable co. STB when they switched over to digital - I'm kinda suspicious on
this. Not that it matters much anyway since the STB's FM modulator doesn't
do stereo anyway, so a direct video/audio hook-up would be the way to go.

Anyway, a standard VCR service involves a video belt/tyre kit, tension
band, brake pads, pinch roller, mode switch, cleaning of video head
and tape path, gear and rail lube. For the sorts of components that
break in a typical VCR, see section 4 of this catalogue:

http://www.wagner.net.au/Sections/

IIRC my Hitachi, which was a great VCR and lasted for years, came back with
the ground strap for the spindle of the drum drive missing - think that
was it anyway.

 

[nobody]

Thanks for the help so far, I am going to replace the caps with the
lower rated caps (1200uf vs 1800uf). Somone posted that replacing
caps on multi-layer boards was very difficult. The 3 caps that caps
that need replacement go all the way through the board and are
soldered on the back of the board. I am assuming that I can just
de-solder the old caps are solder on the new caps without a hitch. My
soldering skills are so-so, but I have soldered and desoldered chips
from old boards before. For example, I replaced the bios chip from an
Atari 7800 system board with a new bios chip to make a cart dumper.
Any advise? Would this be beyond my skill level?

Chris
If life seems jolly rotten
There's spmething you've forgotten
and thats to laugh and smile and dance and sing!

So much pain in you-know-where to salvage an obsolete board that
wasn't a good value even when new (ecs aka pcchips - bad caps are the
proof). These days, a board like this (not the same model, but the
same socket) - new, warranty and all, can be had from Newegg for under
$47 shipped, from ebay even cheaper but no warranty. OTOH, you have
to pay for capacitors, soldering iron and solder(unless you already
have it), wick or vacuum de-solderer, spend at least an hour of your
time - probably even more. The chances for success are not more than
50% - I'm generous with the number. Isn't it easier to just replace
the board or upgrade the whole thing to A64?

NNN

 

[Arno Wagner]

On Wed, 22 Nov 2006 15:37:23 GMT, Chris

So much pain in you-know-where to salvage an obsolete board that
wasn't a good value even when new (ecs aka pcchips - bad caps are the
proof). These days, a board like this (not the same model, but the
same socket) - new, warranty and all, can be had from Newegg for under
$47 shipped, from ebay even cheaper but no warranty. OTOH, you have
to pay for capacitors, soldering iron and solder(unless you already
have it), wick or vacuum de-solderer, spend at least an hour of your
time - probably even more. The chances for success are not more than
50% - I'm generous with the number. Isn't it easier to just replace
the board or upgrade the whole thing to A64?

I would say it is not about cost-efficiency. It is about having the
power to repair a thing and demonstrating it.

Arno