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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
I have a LCD monitor that is wavy and produces more ripple as the
resolution goes up. I have just replaced 2 surface mount capacitors, their ESR ( using Dick Smith meter) readings are 88 and 97 respectively, so there must be bad .. However, the monitor is still wavy after the repair. There are couples of 16V 10uF that goes around 10-17, and according to the chart on the meter , good rating should be around 1.6 Question1: What ESR value is considered to be bad? How many times the bad one has to be larger than the good value on the meter's chart? Question2: Is it possible that the ripple is caused by something other than the dying capacitors? |
#2
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
What ESR value is considered to be bad?
Depends on the Value of capacitance as you can tell from the meter chart. How many times the bad one has to be larger than the good value on the meter's chart? The times depends of the type of cap, there are low ESR caps and low leakage caps. Towit the higher ESR the less ripple that cap can take out compared to a low ESR. of the same value of capacitance. The Lower the ESR the better. Good luck KC8OJU Raymond Borowiak |
#3
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
Instead of trying to pass/fail a electrolytic based only on the chart
it is wise to compare the readings with several new caps from your parts bin..... same value obviously. electricitym .. .. |
#4
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
Are you zero-ing the meter and discharging the caps before taking your
readings? wrote: I have a LCD monitor that is wavy and produces more ripple as the resolution goes up. I have just replaced 2 surface mount capacitors, their ESR ( using Dick Smith meter) readings are 88 and 97 respectively, so there must be bad . However, the monitor is still wavy after the repair. There are couples of 16V 10uF that goes around 10-17, and according to the chart on the meter , good rating should be around 1.6 Question1: What ESR value is considered to be bad? How many times the bad one has to be larger than the good value on the meter's chart? Question2: Is it possible that the ripple is caused by something other than the dying capacitors? |
#6
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
I measured a new one, Panasonic FK serires 16V 10uf(Low esr), the ESR
reading is 1.4, and the old one are about 10-17(the cap's brand is unknown) The good value on the chart is 1.6. Should i replace them if they are at least 6 times larger than the value on the chart? To consider a cap is bad ,How many times the ESR value has to be larger than the good one ? |
#7
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
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#8
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
wrote in message oups.com... I measured a new one, Panasonic FK serires 16V 10uf(Low esr), the ESR reading is 1.4, and the old one are about 10-17(the cap's brand is unknown) The good value on the chart is 1.6. Should i replace them if they are at least 6 times larger than the value on the chart? To consider a cap is bad ,How many times the ESR value has to be larger than the good one ? Although I've said on many occasions that the Dick Smith meter gives unambiguous readings, that statement has to be tempered with a degree of experience. Interpreting ESR readings is a mixture of art and science, and if you deal with the subject a lot, you will rapidly get a " feel " for bad caps. As others have said, a lot depends on capacitor type, and where it is located in the circuit, as to whether its going to cause trouble. Surface mount electros tend to have a higher ' natural ' reading than their corresponding-value conventional types, so it's often a good plan to do a comparison with a known-good similar type. I use a Dick Smith virtually every day, and the chart on the front is, in general, a very good guide, but it should be used as just that, not a definitive good / not good indicator for all cap types. In normal circumstances, I would consider anything giving a reading of twice or more the *expected* value, to be at least on its way, if not truly u/s. Other indicators help with the suspicion of a bad cap. These are - Its proximity to anything that gets hot The ripple ( or other 'AC' ) circumstances under which it normally works, and how hot this causes it to normally run To some extent, the normal voltage that's across it, compared to its rated voltage Arfa |
#9
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
That's an excellent explanation, mate! You wouldn't believe how
many times I've been asked "What's a good and bad ESR reading?" as though it's a hard and fast value for a capacitor like its working voltage is. I'm going to make it into a text file and send it to people when they ask me that question. Thanks!! Regards 'Terry' On Sun, 09 Apr 2006 11:13:56 GMT, "Arfa Daily" wrote: Although I've said on many occasions that the Dick Smith meter gives unambiguous readings, that statement has to be tempered with a degree of experience. Interpreting ESR readings is a mixture of art and science, and if you deal with the subject a lot, you will rapidly get a " feel " for bad caps. As others have said, a lot depends on capacitor type, and where it is located in the circuit, as to whether its going to cause trouble. Surface mount electros tend to have a higher ' natural ' reading than their corresponding-value conventional types, so it's often a good plan to do a comparison with a known-good similar type. I use a Dick Smith virtually every day, and the chart on the front is, in general, a very good guide, but it should be used as just that, not a definitive good / not good indicator for all cap types. In normal circumstances, I would consider anything giving a reading of twice or more the *expected* value, to be at least on its way, if not truly u/s. Other indicators help with the suspicion of a bad cap. These are - Its proximity to anything that gets hot The ripple ( or other 'AC' ) circumstances under which it normally works, and how hot this causes it to normally run To some extent, the normal voltage that's across it, compared to its rated voltage Arfa |
#10
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
"Bob Parker" wrote in message ... That's an excellent explanation, mate! You wouldn't believe how many times I've been asked "What's a good and bad ESR reading?" as though it's a hard and fast value for a capacitor like its working voltage is. I'm going to make it into a text file and send it to people when they ask me that question. Thanks!! Regards 'Terry' Hi Bob Ha ! Fame at last ... Please feel free. What's with " Terry " ? Arfa On Sun, 09 Apr 2006 11:13:56 GMT, "Arfa Daily" wrote: Although I've said on many occasions that the Dick Smith meter gives unambiguous readings, that statement has to be tempered with a degree of experience. Interpreting ESR readings is a mixture of art and science, and if you deal with the subject a lot, you will rapidly get a " feel " for bad caps. As others have said, a lot depends on capacitor type, and where it is located in the circuit, as to whether its going to cause trouble. Surface mount electros tend to have a higher ' natural ' reading than their corresponding-value conventional types, so it's often a good plan to do a comparison with a known-good similar type. I use a Dick Smith virtually every day, and the chart on the front is, in general, a very good guide, but it should be used as just that, not a definitive good / not good indicator for all cap types. In normal circumstances, I would consider anything giving a reading of twice or more the *expected* value, to be at least on its way, if not truly u/s. Other indicators help with the suspicion of a bad cap. These are - Its proximity to anything that gets hot The ripple ( or other 'AC' ) circumstances under which it normally works, and how hot this causes it to normally run To some extent, the normal voltage that's across it, compared to its rated voltage Arfa |
#11
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
On Mon, 10 Apr 2006 01:39:02 GMT, "Arfa Daily"
wrote: Hi Bob Ha ! Fame at last ... Please feel free. What's with " Terry " ? Arfa Just a nickname I pinched from the Minder TV series.... Bob |
#12
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
"Bob Parker" wrote in message ... On Mon, 10 Apr 2006 01:39:02 GMT, "Arfa Daily" wrote: Hi Bob Ha ! Fame at last ... Please feel free. What's with " Terry " ? Arfa Just a nickname I pinched from the Minder TV series.... Bob Duh !! How could I be so dumb ... ??? Arfa |
#13
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
On Mon, 10 Apr 2006 16:39:32 +1000, Bob Parker
wrote: On Mon, 10 Apr 2006 01:39:02 GMT, "Arfa Daily" wrote: Hi Bob Ha ! Fame at last ... Please feel free. What's with " Terry " ? Arfa Just a nickname I pinched from the Minder TV series.... Bob Minder...he was cool! :-) Tom |
#14
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ESR reading?Good/ BAD ESR value? surface mount capacitor cause ripple wavy LCD?
"Tom MacIntyre" wrote in message ... On Mon, 10 Apr 2006 16:39:32 +1000, Bob Parker wrote: On Mon, 10 Apr 2006 01:39:02 GMT, "Arfa Daily" wrote: Hi Bob Ha ! Fame at last ... Please feel free. What's with " Terry " ? Arfa Just a nickname I pinched from the Minder TV series.... Bob Minder...he was cool! :-) Tom I always loved the whole prog, from the first episode of the first series, to the last of the last - hence my tribute to the main character Arthur Daley. Dave, the barman, always used to call him " Arfa " so Arfa.Daily is my little tribute to a great piece of British TV. Arfa |
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