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Suggestions on common capacitors to have on hand

M

Michael Kennedy

Jan 1, 1970
0
What are some common caps I should have on hand for repairs etc? I'm not
sure what I'll be working on in the future, but lately I've been repairing
LCD monitors.

- Mike
 
A

Arfa Daily

Jan 1, 1970
0
Michael Kennedy said:
What are some common caps I should have on hand for repairs etc? I'm not
sure what I'll be working on in the future, but lately I've been repairing
LCD monitors.

- Mike

1000uF 16v, 1000uF 25v, 2200uF 16v, 2200uF 25v, 4700uF 25v, 100uF
25v, 47uF 25v, 22uF 25v, 10uF 50v, 1uF 50v all 105deg types.

0u1 200v, 0u22 200v, 0u47 200v 10nF, 22nF, 47nF, 68nF 100v or 200v.

Everybody will have their own ideas on this, and you're right - it does
depend to some extent on just what you're repairing. For instance, if you
get well into switch mode PSUs, you might want to keep some very good
quality low ESR types, and also some front end smoothers which are usually
in the region of 47 to 220uF at 400v working. If you get into RF work, you
will be wanting some histab small values down in the pF's. The ones that
I've listed above, are the sorts of values that I use regularly in general
hifi, DVD, CD etc repairs. The TV / CRT monitor boys out there will keep
more high voltage types. Over time, you'll get your own collection and
preferences, but something along the lines of the above, should see you ok
for most low voltage work.

Arfa
 
M

Michael Kennedy

Jan 1, 1970
0
Thanks, that gives me a shopping list for the parts store tomorrow. :)

- Mike
 
R

Ross Herbert

Jan 1, 1970
0
What are some common caps I should have on hand for repairs etc? I'm not
sure what I'll be working on in the future, but lately I've been repairing
LCD monitors.

- Mike


While Arfa's suggested list is a good one, I (and probably others)
have discovered that Murphy's Law comes into force with a vengeance
where components are concerned.

i.e.
The capacitor you need for a particular job is nowhwere to be found in
your stock of perhaps several hundred or more.

Not only are capacitance value and voltage important but so to is the
physical size and shape. Often, where value/voltage and/or space is
not critical, you may be able to make do with something other than the
original size which you do have in stock, but over time this is less
likely to be the case.

I have literally 1000's of electro's in stock which have been ordered
in over many years and while they will all measure as new with regard
to ESR, they are physically too large for modern electronics
equipment. Such is the problem where technology advances result in
smaller and smaller components which make the older and larger items
obsolete for many purposes.

Take it from me,,, until you have established the major trend of your
repair trade, buy in only small quantities (eg,5 - 10 off) of the
sizes you are currently using for repairs. Even after you have
established your regular stocking list you will often have to buy in a
special or a one off (usually fairly expensive) for a particular job.
Because you had to do quite a bit of research to find that particular
item you might be tempted to buy 10 or so thinking you might have to
do a similar job some time in the future. You will probably find them
still in the drawer in 5 years time. For smaller types costing less
than 20 - 40 cents it won't be a big loss but for anything over $1
you can end up carrying quite an overhead in non profitable stock.
 
A

Arfa Daily

Jan 1, 1970
0
Ross Herbert said:
While Arfa's suggested list is a good one, I (and probably others)
have discovered that Murphy's Law comes into force with a vengeance
where components are concerned.

i.e.
The capacitor you need for a particular job is nowhwere to be found in
your stock of perhaps several hundred or more.

Not only are capacitance value and voltage important but so to is the
physical size and shape. Often, where value/voltage and/or space is
not critical, you may be able to make do with something other than the
original size which you do have in stock, but over time this is less
likely to be the case.

I have literally 1000's of electro's in stock which have been ordered
in over many years and while they will all measure as new with regard
to ESR, they are physically too large for modern electronics
equipment. Such is the problem where technology advances result in
smaller and smaller components which make the older and larger items
obsolete for many purposes.

Take it from me,,, until you have established the major trend of your
repair trade, buy in only small quantities (eg,5 - 10 off) of the
sizes you are currently using for repairs. Even after you have
established your regular stocking list you will often have to buy in a
special or a one off (usually fairly expensive) for a particular job.
Because you had to do quite a bit of research to find that particular
item you might be tempted to buy 10 or so thinking you might have to
do a similar job some time in the future. You will probably find them
still in the drawer in 5 years time. For smaller types costing less
than 20 - 40 cents it won't be a big loss but for anything over $1
you can end up carrying quite an overhead in non profitable stock.


Note what Ross says Michael. It's all good advice that I totally agree with.
My shop's component drawers are also full of all those slightly too large
electros ... You might have wondered why I specified a couple of different
working voltages for similar values in my list. Ross gives you the answer -
it's all about physical size.

Arfa
 
J

Jeff Liebermann

Jan 1, 1970
0
Arfa Daily said:
My shop's component drawers are also full of all those slightly too large
electros ... You might have wondered why I specified a couple of different
working voltages for similar values in my list. Ross gives you the answer -
it's all about physical size.

Same here. I have all the right values, but not in the right form
factor or size. To solve this problem, I "stock" a large pile of dead
power supplies, motherboards, and cards. If I need a part, I dig out
the Pace desoldering contraption and pull a few. It's also a great
excuse not to clean up the mess in the shop and to justify keeping old
junk around. When I pull an electrolytic cazapitor, I always test it
with the capitance meter for value, and the ESR meter, for quality.
 
A

Arfa Daily

Jan 1, 1970
0
Jeff Liebermann said:
Same here. I have all the right values, but not in the right form
factor or size. To solve this problem, I "stock" a large pile of dead
power supplies, motherboards, and cards. If I need a part, I dig out
the Pace desoldering contraption and pull a few. It's also a great
excuse not to clean up the mess in the shop and to justify keeping old
junk around. When I pull an electrolytic cazapitor, I always test it
with the capitance meter for value, and the ESR meter, for quality.

Again, this is good advice. A few months back, I got offered a bagfull of
two different types of brand new ( smallish ) switchers. They are an
endlessly useful source of electrolytics and Schottky diodes. I also keep a
box full of replaced DVD decks. It's amazing how often gears and such from
these, come in useful. The Panasonic audio CD " traverse deck " for
instance, has a number of plastic pins moulded into it. These are a perfect
size to replace the cassette door latch pins that break off on Aiwa units,
when the belts slip, the mech locks up, and the owners animalise the door
open. You'll have to be patient on this Michael. It takes years to build up
a useful parts inventory, and to gain the necessary trade savvy to know
what's worth keeping, and what needs junking, not that I think I know any
engineer who's got that last part quite right ... !!

Arfa
 
C

carneyke

Jan 1, 1970
0
Arfa,
The only thing you forgot to mention was "Now where did I put that part
that can be used to fix this". He he he !!!
 
J

Jeff Liebermann

Jan 1, 1970
0
carneyke said:
The only thing you forgot to mention was "Now where did I put that part
that can be used to fix this". He he he !!!

I use the same method as archeologists. Chronological layering.
"The last time I saw this part was about 6 months ago, so it should be
about 6 inches from the top of the debris pile". I use the same
method for filing documents. I fill up a cardboard storage box and
insert dividers with the date visible. I don't have to remember where
I put something, just when I buried it.
 
T

Tom MacIntyre

Jan 1, 1970
0
I use the same method as archeologists. Chronological layering.
"The last time I saw this part was about 6 months ago, so it should be
about 6 inches from the top of the debris pile". I use the same
method for filing documents. I fill up a cardboard storage box and
insert dividers with the date visible. I don't have to remember where
I put something, just when I buried it.

Ha...I hear you. I returned to my dorm room from the shower one day at
university to find that my girlfriend had arrived and "cleaned up" the
foot+ deep pile of stuff on my desk. I had to be polite, but it took
me weeks to "reorganize" my stuff the way I needed it to be. :)

Tom
 
M

mc

Jan 1, 1970
0
I use the same method as archeologists. Chronological layering.
Ha...I hear you. I returned to my dorm room from the shower one day at
university to find that my girlfriend had arrived and "cleaned up" the
foot+ deep pile of stuff on my desk. I had to be polite, but it took
me weeks to "reorganize" my stuff the way I needed it to be. :)

Didn't Sherlock Holmes once complain to Mrs. Hudson that she had removed an
essential element of his filing system -- the dust?

Without it, you can't see the chronological order. Of course, being Holmes,
he could reconstruct it, but he'd rather be doing something else.
 
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