Cap testing question

I have a computer that won't turn on unless it is warm enough. The
problem is in the power supply. If I use a blow drier to blow some
warm air through the exhaust holes in the power supply for a minute or
two the power supply starts working. I was told by someone here or on
the basics group that there is probably a bad electrolytic capacitor
causing the problem. I also have a CNC machine that has a servo amp
that acts the same. The machine must be on for a while and when the
cabinet that holds the servo amps gets warm enough inside the amp
start working and will work fine as long as the machine is kept
powered up. If the machine is turned off for an hour or so and then
powered back up the amp still works. But if the machine is off
overnight the amp acts the same as above. I replaced the amp so there
is no problem running the machine but I would like to repair this amp
so I can have a spare on the shelf. Anyway, it has only 3 physically
large electrolytic caps. I unsoldered one lead from each cap and
measured the capacitance with my Extech multimeter. The two 10 uf caps
measured 11. something uf and the 33 uf cap measured 37. something.
Could these caps be bad anyway? There are also three blue colored
dipped caps that have printed on them: .068K 250. I don't what the dot
in the .068K means but I don't think it's a decimal point. Maybe it
means lead free. There are also a couple 47 uf wound polymer caps.
Could either of these types of caps need to be warm before they work
properly? I have no schematic for this amp and have not been able to
get one. Furthermore, the company that makes this servo amp has ground
the markings off of any device with more than three leads.
Thanks,
Eric

 

On Friday, May 6, 2016 at 3:02:30 PM UTC-4, et...@whidbey.com wrote:

I have a computer that won't turn on unless it is warm enough. The
problem is in the power supply. If I use a blow drier to blow some
warm air through the exhaust holes in the power supply for a minute or
two the power supply starts working. I was told by someone here or on
the basics group that there is probably a bad electrolytic capacitor
causing the problem. I also have a CNC machine that has a servo amp
that acts the same. The machine must be on for a while and when the
cabinet that holds the servo amps gets warm enough inside the amp
start working and will work fine as long as the machine is kept
powered up. If the machine is turned off for an hour or so and then
powered back up the amp still works. But if the machine is off
overnight the amp acts the same as above. I replaced the amp so there
is no problem running the machine but I would like to repair this amp
so I can have a spare on the shelf. Anyway, it has only 3 physically
large electrolytic caps. I unsoldered one lead from each cap and
measured the capacitance with my Extech multimeter. The two 10 uf caps
measured 11. something uf and the 33 uf cap measured 37. something.
Could these caps be bad anyway? There are also three blue colored
dipped caps that have printed on them: .068K 250. I don't what the dot
in the .068K means but I don't think it's a decimal point. Maybe it
means lead free. There are also a couple 47 uf wound polymer caps.
Could either of these types of caps need to be warm before they work
properly? I have no schematic for this amp and have not been able to
get one. Furthermore, the company that makes this servo amp has ground
the markings off of any device with more than three leads.
Thanks,
Eric

Yes, caps that read good value can still be bad. Most electrolytics that are bad will show high ESR readings (bad) before they show low capacitance. ESR meters are cheap enough that anyone who screws with electronics should have one. Despite the advice of others, I always remove the capacitor to test ESR with an "in-circuit" ESR tester.

Also, a good percentage of wonky electrolytics will show signs of venting at the top of the cap, if not an actual electrolyte leakage, then a discernible bulge. If you see any bulged caps, change them.

Most small disc and film caps will not become temperature sensitive. For a device to be warm up sensitive like your device it's usually a weak electrolytic , so concentrate there.

If there's only a few electrolytics, change them all with good quality (I like Panasonic) caps and they'll probably run.

 

I would first put the caps back in the circuit and see if it still behaves the same way. Your unsoldering and re-soldering may have fixed things due to a cold solder joint or other possible connection problems.

 

[pfjw@aol.com]

Mpfff.... Some basics on electrolytic caps:

a) an electrolytic cap, unless otherwise marked can test +100%/-20% for value and still be in spec. And unless you have the ability to test them at full operating voltage, the information from a typical DVM is incomplete.
b) an ESR meter is your friend. As noted elsewhere, testing is best done out of circuit.
c) switching power supplies are very hard on caps.

Replace them anyway, but also as noted, look for other heat sensitive failures also!

Peter Wieck
Melrose Park, PA

 

[Randy Day]

In article <t2opiblcf3u910hulv3na3u5haf4a3ackr@4ax.com>,
etpm@whidbey.com says...

I have a computer that won't turn on unless it is warm enough. The
problem is in the power supply. If I use a blow drier to blow some

Bad caps are certainly one possibility,
but there are other things to check for
as well.

There could be a cold solder joint that
makes contact when a lead expands with
heat.

A connector may have a bit of corrosion
that slips away when the metal contacts
slide past each other under heating.
Try disconnecting and reseating all
connectors.

Intermittent issues like these can be
a pain to diagnose...

--- news://freenews.netfront.net/ - complaints: news@netfront.net ---

 

[Ralph Mowery]

In article <4e956b9c-7245-474d-adf7-012b51bb3989@googlegroups.com>,
ohger1s@gmail.com says...

On Friday, May 6, 2016 at 3:02:30 PM UTC-4, et...@whidbey.com wrote:
I have a computer that won't turn on unless it is warm enough. The
problem is in the power supply. If I use a blow drier to blow some
warm air through the exhaust holes in the power supply for a minute or
two the power supply starts working. I was told by someone here or on
the basics group that there is probably a bad electrolytic capacitor
causing the problem. I also have a CNC machine that has a servo amp
that acts the same. The machine must be on for a while and when the
cabinet that holds the servo amps gets warm enough inside the amp
start working and will work fine as long as the machine is kept
powered up. If the machine is turned off for an hour or so and then
powered back up the amp still works. But if the machine is off
overnight the amp acts the same as above. I replaced the amp so there
is no problem running the machine but I would like to repair this amp
so I can have a spare on the shelf. Anyway, it has only 3 physically
large electrolytic caps. I unsoldered one lead from each cap and
measured the capacitance with my Extech multimeter. The two 10 uf caps
measured 11. something uf and the 33 uf cap measured 37. something.
Could these caps be bad anyway? There are also three blue colored
dipped caps that have printed on them: .068K 250. I don't what the dot
in the .068K means but I don't think it's a decimal point. Maybe it
means lead free. There are also a couple 47 uf wound polymer caps.
Could either of these types of caps need to be warm before they work
properly? I have no schematic for this amp and have not been able to
get one. Furthermore, the company that makes this servo amp has ground
the markings off of any device with more than three leads.
Thanks,
Eric

Yes, caps that read good value can still be bad. Most electrolytics that are bad will show high ESR readings (bad) before they show low capacitance. ESR meters are cheap enough that anyone who screws with electronics should have one. Despite the advice of others, I always remove the capacitor to test ESR with an "in-circuit" ESR tester.

Also, a good percentage of wonky electrolytics will show signs of venting at the top of the cap, if not an actual electrolyte leakage, then a discernible bulge. If you see any bulged caps, change them.

Most small disc and film caps will not become temperature sensitive. For a device to be warm up sensitive like your device it's usually a weak electrolytic , so concentrate there.

If there's only a few electrolytics, change them all with good quality (I like Panasonic) caps and they'll probably run.

I agree with changing all the electrolytics as there are only a couple
of them. Even though the value may check out ok , there could be other
problems with them such as the ESR value.

I would guess the .068K would be a .068 UF at 250 volts. They seldom go
bag. If only a few of the 47 uf you might as well change them while you
are at it.

While you could have other problems, the heating up seems to indicate
the classic bad capacitors in the power supply.

 

>" If you see any bulged caps, change them. "

Note that does NOT apply to the big huge ones. Like the 470/200 main raw B+ filter for example, or those 10,000 at 80 volts in an amplifier.

When it has that plastic sheath over it, the bulging top does NOT indicate it is bad.

A guy I used to work with was told that and changed a like 470/200 and that did not fix the set, of course because it was not bad and he was not a real tech, he just did what he was told. Well days later I get to work on it because nobody else could fix it. The cap was in a bag with the screws and replaced parts. The cap was still charged !

That doesn't mean it could not have high ESR, but it was definitely not the cause of the problem. There are people who like to change ALL the caps in old hifi amps, I think they're wrong. While I will agree with changing the corresponding cap in the other channel when you find a bad one, or even weak one (significant ESR compared to Xc) it does not good to just change them all arbitrarily.

It depends on where they are in the circuit, if used for bypass, what kind of current drain ? If used for coupling, what impedences ? It matters.

 

[Jeff Liebermann]

On Fri, 06 May 2016 12:05:35 -0700, etpm@whidbey.com wrote:

I have a computer that won't turn on unless it is warm enough. The
problem is in the power supply. If I use a blow drier to blow some
warm air through the exhaust holes in the power supply for a minute or
two the power supply starts working. I was told by someone here or on
the basics group that there is probably a bad electrolytic capacitor
causing the problem.
(...)

Those are the classic symptoms of a defective electrolytic capacitor.
You can't test an electrolytic with just a capacitance meter. you
need an ESR (equivalent series resistance) meter. Often, I see them
with the right capacitance, but with a high ESR. It's a common
problem:
<http://802.11junk.com/jeffl/pics/repair/slides/bad-caps.html>
Notice how some of them are bulging at the top or bottom. As others
have mentioned, it probably best to do an pre-emptive replacement than
to try an save a few pennies seperating the good from the bad caps. In
general, if one electrolytic is bad, they're all bad.

After some provocation by Phil Allison, I ran a temperature test on
various electrolytic capacitors:
<http://802.11junk.com/jeffl/Electrolytic-cap-test/>
Simple setup:
<http://802.11junk.com/jeffl/Electrolytic-cap-test/test-setup.jpg>
Test caps:
<http://802.11junk.com/jeffl/Electrolytic-cap-test/caps.jpg>
Spreadsheet showing results of temp test:
<http://802.11junk.com/jeffl/Electrolytic-cap-test/cap-esr-test.xls>
Notice how the ESR improves (goes down) with increasing temperature.
That's why your power supply screws up at room temperature, but works
when it's warmed up.

There are a number of different ESR meters available. If you plan on
doing such repairs in the future, you really should buy one. If
you're not sure which one is suitable, I don't have any experience
with this one, but it sure is cheap:
<http://www.ebay.com/itm/131645169017>


--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Ralph Mowery]

In article <u1aqib12s73m6c57gjicuk5rkqk18d78cl@4ax.com>,
jeffl@cruzio.com says...

There are a number of different ESR meters available. If you plan on
doing such repairs in the future, you really should buy one. If
you're not sure which one is suitable, I don't have any experience
with this one, but it sure is cheap:
http://www.ebay.com/itm/131645169017

For a few dollars more you can get them already put together. I bought
a similar one a few years back. Not sure how well it does the ESR but
usually does a good job of testing many components.

 

[Phil Allison]

Jeff Liebermann wrote:

Those are the classic symptoms of a defective electrolytic capacitor.

** Or several OR a dry solder joint or many of them.

After some provocation by Phil Allison, I ran a temperature test on
various electrolytic capacitors:
http://802.11junk.com/jeffl/Electrolytic-cap-test/
Simple setup:
http://802.11junk.com/jeffl/Electrolytic-cap-test/test-setup.jpg

** You went to lot of trouble to see the obvious.

All I did was try a few 450V electros, heat them with a hot air gun until they were darn uncomfortable to hold and note that in every case the ESR reading had plumeted by 5 to 10 times.

Then I found some graphs on-line that backed up the finding.

There are a number of different ESR meters available.

** I use the same one as in your pics - the Bob Parker design. He lives not far from me and we have conversed about that an many other electronics matters.

Have you tried your meter to test the ESR of cells ?

Easy to tell if a Lithium memory cell is good or not - also good on NiCds, NiMH and alkalines.

Also reads low value resistors, even if there is an inductor or transformer winding across one.


..... Phil

 

[pfjw@aol.com]

On Friday, May 6, 2016 at 8:30:29 PM UTC-4, jurb...@gmail.com wrote:

> When it has that plastic sheath over it, the bulging top does NOT indicate it is bad.

Ummmm..... Not on my watch! I do keep an ESR meter, and I also keep a cap-tester that can test at actual operating voltages and in AC or DC. ANY physical indications of ANY nature other than friction or impact will get a cap changed. And every electrolytic in an item that affects the perceived problem will get tested with that ESR meter. When in doubt, change it out.

The problem with swelling is that it may not be affecting the cap *today*. And the actual stresses on the cap may be well below its rating. But when (not if) it fails, it will be at the most awkward possible moment and take much with it. Murphy's Law. Caps, even very good ones, are much cheaper than the time it takes to replace them. Just keep that in mind.

Peter Wieck
Melrose Park, PA

 

[pfjw@aol.com]

On Saturday, May 7, 2016 at 8:18:08 AM UTC-4, jeanyves wrote:

On 2016-05-06 19:05:35 +0000, etpm@whidbey.com said:

I have a computer that won't turn on unless it is warm enough. The
problem is in the power supply. If I use a blow drier to blow some
warm air through the exhaust holes in the power supply for a minute or
two the power supply starts working. I was told by someone here or on
the basics group that there is probably a bad electrolytic capacitor
causing the problem. I also have a CNC machine that has a servo amp
that acts the same. The machine must be on for a while and when the
cabinet that holds the servo amps gets warm enough inside the amp
start working and will work fine as long as the machine is kept
powered up. If the machine is turned off for an hour or so and then
powered back up the amp still works. But if the machine is off
overnight the amp acts the same as above. I replaced the amp so there
is no problem running the machine but I would like to repair this amp
so I can have a spare on the shelf. Anyway, it has only 3 physically
large electrolytic caps. I unsoldered one lead from each cap and
measured the capacitance with my Extech multimeter. The two 10 uf caps
measured 11. something uf and the 33 uf cap measured 37. something.
Could these caps be bad anyway? There are also three blue colored
dipped caps that have printed on them: .068K 250. I don't what the dot
in the .068K means but I don't think it's a decimal point. Maybe it
means lead free. There are also a couple 47 uf wound polymer caps.
Could either of these types of caps need to be warm before they work
properly? I have no schematic for this amp and have not been able to
get one. Furthermore, the company that makes this servo amp has ground
the markings off of any device with more than three leads.
Thanks,
Eric

lots of esr meters to choose from : to build or to buy
http://kripton2035.free.fr/esr-repository.html

--

Jean-Yves.

I keep the "Blue" meter. Easy to use and as tested against others, quite accurate.

Peter Wieck
Melrose Park, PA

 

[N_Cook]

On 06/05/2016 20:05, etpm@whidbey.com wrote:

I have a computer that won't turn on unless it is warm enough. The
problem is in the power supply. If I use a blow drier to blow some
warm air through the exhaust holes in the power supply for a minute or
two the power supply starts working. I was told by someone here or on
the basics group that there is probably a bad electrolytic capacitor
causing the problem. I also have a CNC machine that has a servo amp
that acts the same. The machine must be on for a while and when the
cabinet that holds the servo amps gets warm enough inside the amp
start working and will work fine as long as the machine is kept
powered up. If the machine is turned off for an hour or so and then
powered back up the amp still works. But if the machine is off
overnight the amp acts the same as above. I replaced the amp so there
is no problem running the machine but I would like to repair this amp
so I can have a spare on the shelf. Anyway, it has only 3 physically
large electrolytic caps. I unsoldered one lead from each cap and
measured the capacitance with my Extech multimeter. The two 10 uf caps
measured 11. something uf and the 33 uf cap measured 37. something.
Could these caps be bad anyway? There are also three blue colored
dipped caps that have printed on them: .068K 250. I don't what the dot
in the .068K means but I don't think it's a decimal point. Maybe it
means lead free. There are also a couple 47 uf wound polymer caps.
Could either of these types of caps need to be warm before they work
properly? I have no schematic for this amp and have not been able to
get one. Furthermore, the company that makes this servo amp has ground
the markings off of any device with more than three leads.
Thanks,
Eric

ISTR once coming across a failed zener in a smps causing this works when
warm syptom

 

[N_Cook]

On 06/05/2016 20:05, etpm@whidbey.com wrote:

I have a computer that won't turn on unless it is warm enough. The
problem is in the power supply. If I use a blow drier to blow some
warm air through the exhaust holes in the power supply for a minute or
two the power supply starts working. I was told by someone here or on
the basics group that there is probably a bad electrolytic capacitor
causing the problem. I also have a CNC machine that has a servo amp
that acts the same. The machine must be on for a while and when the
cabinet that holds the servo amps gets warm enough inside the amp
start working and will work fine as long as the machine is kept
powered up. If the machine is turned off for an hour or so and then
powered back up the amp still works. But if the machine is off
overnight the amp acts the same as above. I replaced the amp so there
is no problem running the machine but I would like to repair this amp
so I can have a spare on the shelf. Anyway, it has only 3 physically
large electrolytic caps. I unsoldered one lead from each cap and
measured the capacitance with my Extech multimeter. The two 10 uf caps
measured 11. something uf and the 33 uf cap measured 37. something.
Could these caps be bad anyway? There are also three blue colored
dipped caps that have printed on them: .068K 250. I don't what the dot
in the .068K means but I don't think it's a decimal point. Maybe it
means lead free. There are also a couple 47 uf wound polymer caps.
Could either of these types of caps need to be warm before they work
properly? I have no schematic for this amp and have not been able to
get one. Furthermore, the company that makes this servo amp has ground
the markings off of any device with more than three leads.
Thanks,
Eric

I've seen a dot on ICs signifying PbF

 

[jeanyves]

On 2016-05-06 19:05:35 +0000, etpm@whidbey.com said:

I have a computer that won't turn on unless it is warm enough. The
problem is in the power supply. If I use a blow drier to blow some
warm air through the exhaust holes in the power supply for a minute or
two the power supply starts working. I was told by someone here or on
the basics group that there is probably a bad electrolytic capacitor
causing the problem. I also have a CNC machine that has a servo amp
that acts the same. The machine must be on for a while and when the
cabinet that holds the servo amps gets warm enough inside the amp
start working and will work fine as long as the machine is kept
powered up. If the machine is turned off for an hour or so and then
powered back up the amp still works. But if the machine is off
overnight the amp acts the same as above. I replaced the amp so there
is no problem running the machine but I would like to repair this amp
so I can have a spare on the shelf. Anyway, it has only 3 physically
large electrolytic caps. I unsoldered one lead from each cap and
measured the capacitance with my Extech multimeter. The two 10 uf caps
measured 11. something uf and the 33 uf cap measured 37. something.
Could these caps be bad anyway? There are also three blue colored
dipped caps that have printed on them: .068K 250. I don't what the dot
in the .068K means but I don't think it's a decimal point. Maybe it
means lead free. There are also a couple 47 uf wound polymer caps.
Could either of these types of caps need to be warm before they work
properly? I have no schematic for this amp and have not been able to
get one. Furthermore, the company that makes this servo amp has ground
the markings off of any device with more than three leads.
Thanks,
Eric

lots of esr meters to choose from : to build or to buy
http://kripton2035.free.fr/esr-repository.html

--

Jean-Yves.

 

[DaveC]

That doesn't mean it could not have high ESR, but it was definitely not the
cause of the problem. There are people who like to change ALL the caps in old
hifi amps, I think they're wrong. While I will agree with changing the
corresponding cap in the other channel when you find a bad one, or even weak
one (significant ESR compared to Xc) it does no good to just change them all
arbitrarily.

Sure it does. If the problem is with one of these caps, changing them
arbitrarily FIXES the problem.

“Penny wise, pound foolish.” Yes, you’re right, finding the ONE cap
that is the cause is technically proficient. But just to say “I found the
culprit!” does not help the customer (or yourself, if it’s you). The unit
will be back on your bench very soon if you don’t replace all electros now,
if you find one or more below spec.

 

[DaveC]

Simple setup:
http://802.11junk.com/jeffl/Electrolytic-cap-test/test-setup.jpg

Bob Parker / Dick Smith / Silicon Chip meter!!!

Bob is the original designer of this meter. Last I looked Bob was still
giving help to builders of his kit.

 

[DaveC]

Bob Parker / Dick Smith / Silicon Chip meter!!!

Bob is the original designer of this meter. Last I looked Bob was still
giving help to builders of his kit.

http://members.ozemail.com.au/~bobpar/esrmeter.htm

 

[Jeff Liebermann]

On Sat, 7 May 2016 00:02:40 -0700 (PDT), Phil Allison
<pallison49@gmail.com> wrote:

Jeff Liebermann wrote:
After some provocation by Phil Allison, I ran a temperature test on
various electrolytic capacitors:
http://802.11junk.com/jeffl/Electrolytic-cap-test/
Simple setup:
http://802.11junk.com/jeffl/Electrolytic-cap-test/test-setup.jpg

** You went to lot of trouble to see the obvious.

Cap-B was one that had failed with high ESR. There was plenty of data
and anecdotal evidence on how a normal capacitor would act. I wanted
to see how a defective capacitor acted. I also wanted to see how the
ESR meter functioned with small value and size (0.22uF 50v) caps,
which was Cap-D. The change in ESR with temp was far less radical
than the others.
<http://802.11junk.com/jeffl/Electrolytic-cap-test/Cap-D.jpg>
I also found as similar problem with high capacitance values (1800uF
6.3v) which was Cap-A, where the lower limit capability of the ESR
meter (about 0.03 ohms) also caused the graph to flat line. I didn't
mention this in your previous discussion on the matter, but I was
trying to determine if it made sense to use a fixed 100KHz sine wave
signal, and whether higher or lower frequencies might help test a
wider range of capacitance values. I have a pathological aversion to
accepting the obvious, and will take the time to test the obvious,
which invariably produce surprises.

All I did was try a few 450V electros, heat them with a hot air
gun until they were darn uncomfortable to hold and note that in
every case the ESR reading had plumeted by 5 to 10 times.

I wasn't interested in high voltage electrolytics. There are usually
two of those in a typical ATX power supply. They never seem to fail.
It's the low voltage electrolytics, that inhabit the output filters
and regulator circuitry that fail and were of interest to me. I
probably could have done it using your method, but I thought a hot
water bath was more interesting and accurate.

There are a number of different ESR meters available.

** I use the same one as in your pics - the Bob Parker design. He
lives not far from me and we have conversed about that an many
other electronics matters.

Yep. It's an impressive instrument, quite accurate, but a little
tricky to build (Dick Smith kit version). Methinks the later "blue"
variety might be better.
<http://anatekinstruments.com/products/fully-assembled-anatek-blue-esr-meter-besr>

Have you tried your meter to test the ESR of cells ?
Easy to tell if a Lithium memory cell is good or not - also good on
NiCds, NiMH and alkalines.

One of the common modifications to the original ESR meter is to add
two back to back power diodes across the input to protect the meter
from residual voltages. The problem with doing that is that the
diodes short out the battery. Since I expected to be testing far more
capacitors than batteries, this made sense.

I also have a Capacitor Wizard ESR meter that I picked up cheap at a
flea market:
<http://anatekinstruments.com/products/capacitor-wizard-esr-tester-cap1b>
<http://anatekinstruments.com/products/capacitor-wizard-esr-tester-with-capsvr-module-cap1b-capsvr>
The CapSRV model has the same diode protection circuit making it
useless for battery measurements. There's nothing particularly
wonderful about this meter except that it's very fast and convenient.
One problem is that I seem to have misplaced it and can't seem to find
it. Argh.

I also have a Peak Atlas ESR70 "purple" ESR meter.
<http://www.peakelec.co.uk/acatalog/jz_esr70.html>
It has a built in discharge resistor to help deal with charged
capacitors and therefore is useless for testing battery ESR.

Bottom line is that I don't use any of my ESR meters to test
batteries. I probably should build or buy something specifically for
the purpose to see what I'm missing. All of my battery testing
involve small rechargeable batteries, a discharge tester, and
computized graphs such as:
<http://802.11junk.com/jeffl/LiPo/Ultrafire%2018650%20test.jpg>
<http://802.11junk.com/jeffl/LiPo/Ultrafire%20LiPo%203000%20ma-hr%2018650%20test.jpg>
However, I'm getting into larger cells and sealed packs, where an ESR
tester is quicker and probably more useful.

Also reads low value resistors, even if there is an inductor or
transformer winding across one.

Yep. I've used that to determine the value of a charred resistor.
Usually, it's a wire wound resistor with a break somewhere along the
winding. I measure from one lead to the middle of the winding. One
end is usually open, while the other end reads half the resistor
value. However, testing electrolytics is my main use for an ESR
meter.

>.... Phil

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

 

[Fred McKenzie]

In article <MPG.3196c6b2ce898bd39896a0@news.east.earthlink.net>,
Ralph Mowery <rmowery28146@earthlink.net> wrote:

I would guess the .068K would be a .068 UF at 250 volts. They seldom go
bag.

I agree. The K probably indicates 10% tolerance.

Regardless, it is either .068 Microfarads or 68K (68,000) Picofarads,
which is the same thing!

Fred