Re: Weird ESR readings
Come on guys, as I said I'm a beginner. I've read about lifting tracks and irremediably damaging boards, so until I master component removal I stay away from that. And I need some dead boards to practice on. At the moment I'm studying mostly how things work, how to use meters, how to interpret ESR readings and so on. I learn a lot just by testing my TV.
Also, while searching for more info on flyback transformers, I came across an electronics forum where a guy had just fixed the same problem on the same TV as mine by replacing a dried out capacitor....
cib3k
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Last Activity: 06-02-2021, 04:20 PM
Joined: 07-06-2011
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Last edited by cib3k; 01-08-2014, 09:17 AM. -
Re: Weird ESR readings
At the moment I'm just looking around, I'd rather not take components off board unless I'm quite sure they're bad. I prefer analyzing things rather than randomly disconnecting components. I'm a beginner and this way I'm trying to learn more about electronics. Thanks for the transformer tip, I'll look into it.Leave a comment:
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Weird ESR readings
I have an old LG CRT TV from 2001. The image expands when I turn the contrast up, and shrinks when I turn it down. I'm trying to see if I can fix this. I started testing capacitors (in circuit), and I've got some weird readings for 2 of them.
The first one is 160V 100uF. When I try to measure ESR, I get a flashing [B]-0[/B]. If I reverse polarity, I get the same [B]-0[/B]. If I only touch the capacitor leads for a moment, I get some large values: 50, 90, even 100 ohms.
Using my multimeter to measure resistance on the 20K scale, I get values that increase up to 2.8K... -
Re: Is testing ESR enough?
And just to be clear: I know that ESR and capacitance are different things, and that ESR can be measured in circuit.
Also, another question: why do most multimeters that measure capacitance only go as high as 20uF-200uF? I've seen 2200uF electrolytics in PSUs and 3300uF on motherboards, so higher capacitances are pretty common. Is there a problem with accuracy, maybe?Last edited by cib3k; 11-04-2013, 05:04 PM.Leave a comment:
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Is testing ESR enough?
I was wondering: if you remove a capacitor from a circuit, you test its ESR and it seems fine for its stated capacitance, does it mean the capacitor is fine? Would an additional capacitance test be relevant? I'm asking this because I'm already using an ESR meter, my multimeter doesn't test capacitors, and I was wondering if an additional capacitance meter/multimeter would be worth the investment for hobby repairs. Does the ESR test (out of circuit) make the capacitance test obsolete? Sorry if it's a stupid question, I'm a beginner.Last edited by cib3k; 11-04-2013, 03:30 PM. -
Re: Power adapter wasting a lot of energy
The meter was the culprit. It doesn't measure properly small loads. After adding a 75W incandescent light bulb to increase the load, it started giving more accurate readings. The power adapter is fine, it draws nothing when off, and around 1W when the laptop is in standby.Leave a comment:
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Re: Power adapter wasting a lot of energy
Thanks for the answers. I was using an inexpensive digital wattmeter/energy meter for the measurements, and it's possible that I was getting false readings either due to the low power being measured or to the burst mode rievax_60 mentioned. If the burst mode is to blame, how do you measure that properly? Is a regular multimeter good enough, or do you need some special equipment?Leave a comment:
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Power adapter wasting a lot of energy
I was measuring standby power around my home with a power meter, when I noticed that my laptop's power adapter was wasting 21 watts with the laptop turned off. I tried disconnecting it from the laptop - nothing changed. Even weirder, the next day it was only using 18w without any load. I tested other power bricks that I had around - the maximum I got was 9w without a load. So 18-21w was definitely too much.
I know that I can use a power strip and turn it off when not in use, but I'm curious what's going on. I don't think it wastes that much energy by design, so there must be a... -
Re: cheaper Hakko tips
They're only copper plated? Wow. I didn't imagine that. On the bright side, as they're cheap, I can cut one in half. If it's solid copper inside, I'll buy more. I'm a beginner and I'm experimenting at the moment with various sizes and shapes, so I need to buy several tips.Leave a comment:
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cheaper Hakko tips
I need to buy some tips for my soldering station, and I'm not sure where to buy them from. Some time ago, PCBONEZ [URL="https://www.badcaps.net/forum/showpost.php?p=203566&postcount=9"]was writing[/URL] about [URL="http://www.vendio.com/stores/cantonmadecom/"]a seller in China[/URL] who was selling Hakko tips that seemed genuine. This seller still has a store on Vendio, the problem is that each tip is listed 3 times (see [URL="http://www.vendio.com/stores/cantonmadecom/item/radios-cb-ham-shortwave-parts-/900m-t-0-8c-hakko-soldering-ti/lid=2873687"]here[/URL],... -
Re: Buying used Metcal stations
Well, I guess I'll just follow the auctions. It seems there's a station popping on from time to time. The problem is mainly the shipping to my country.Last edited by cib3k; 07-08-2011, 06:54 AM.Leave a comment:
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Buying used Metcal stations
Hi all, this is my first post on this great forum.
I have a question for people in Europe - if you'd want to buy a used Metcal station, where would you look for it? I tried ebay, but I get very few results, and half of them are books by various people called "Metcal". The actual stations that are for sale are way too expensive. I'm looking for something below 150 pounds/euro, and not the OKI PS-800/900 models.
So, what should I do? Just follow the auctions, hoping that I will find a deal that suits me? Are there any forums with a sell/buy section where I...
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