Author Topic: Which Oscilloscope to buy for Computer repair  (Read 15968 times)

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Offline dev9393

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Which Oscilloscope to buy for Computer repair
« on: September 07, 2013, 07:24:47 pm »
Hi there to all masters , Sir's actually i am an Automobile engg (32yrs back )For last 1to2yrs i am repairing computers (hobby) and want to shift permanently to this field   , now i want to buy an oscilloscope and i am a big ZERO when it comes to the finer points of electronics .The frequencies used are (1)32.768KHz -South bridge  (2) 25MHz-- Ethernet (3)Audio Codec--24.567 MHz  (4)Clock Synthesizer--14.318MHz  (5)Micro controller--10MHz (6)Embedded Controller--32.768KHz (7)DSP--14.318MHz (8) GPU (MCH+ICH+CLK)--25MHz,27MHz,32.768KHz .I am not taking RAM in a/c.Now i have read that the accuracy of oscilloscope is 1/5 (one fifth) of its band width is it true? AS i am planing to buy Rigol 1102e 100MHZ is it sufficient for above mention frequencies also checking gate signals of Mosfet etc.OR should i get 1102d of which (analyzer )i know nothing.Please advice 
 

Offline Legit-Design

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Re: Which Oscilloscope to buy for Computer repair
« Reply #1 on: September 07, 2013, 08:18:41 pm »
What are you going to repair in computers? As far as I know computer repair is finding the fault and replacing whole modules, replace power supply, replace motherboard, replace what doesnt work since repairing it is going to cost alot unless you work for free or still as a hobby. Normal repair of non functioning laptop is a motherboard replacement. When computer power supply craps out it is just cheaper to get new one, or get a proper good quality psu so it will run for years. Depending where you live repairing something electronics level will not pay, compared to getting functioning part and just replacing it.
Even replacing faulty caps falls into hobby category, I can't see anyone doing it full time and getting good pay out of it.

If you just want to get oscilloscope and tell yourself it's for computer repair, there are already lots of threads discussing about buying proper scope. Rigol 1052E or 2072 seem to be popular and proven themselves in use.
« Last Edit: September 07, 2013, 08:22:52 pm by Legit-Design »
 

Offline amyk

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Re: Which Oscilloscope to buy for Computer repair
« Reply #2 on: September 07, 2013, 10:32:56 pm »
What are you going to repair in computers? As far as I know computer repair is finding the fault and replacing whole modules, replace power supply, replace motherboard, replace what doesnt work since repairing it is going to cost alot unless you work for free or still as a hobby. Normal repair of non functioning laptop is a motherboard replacement. When computer power supply craps out it is just cheaper to get new one, or get a proper good quality psu so it will run for years. Depending where you live repairing something electronics level will not pay, compared to getting functioning part and just replacing it.
Even replacing faulty caps falls into hobby category, I can't see anyone doing it full time and getting good pay out of it.
Take a visit to southeast Asia sometime...
 

Offline dev9393

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Re: Which Oscilloscope to buy for Computer repair
« Reply #3 on: September 07, 2013, 11:41:36 pm »
Hi, I  live in India and here we do not replace  but repair the boards right down to chip level (reflowing,reballing or replacement  of chip),some times it is just a faulty mosfet, pwm chip,  or a SMD (Resistor, Capacitor, transistor, Gates etc) and mother board(laptop or desktop)is working again.So it is necessary to pin point the fault,as the working is mainly of Voltages and Signals,hence the need of an oscilloscope. 
 

Offline Legit-Design

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Re: Which Oscilloscope to buy for Computer repair
« Reply #4 on: September 08, 2013, 12:50:21 am »
My bad, I was thinking everyone lives in a modern western country. Countries where trashbins are just filled with working stuff that people throw away because it's old, noisy and big, so they can replace it with iPads and such.

My sources for parts aren't as good as dumpster room at EEVBlog corporate headquarters, but if I am at the right place at right time, then free working stuff is guaranteed. Also where I live selling reflowed computer equipment is considered grey area, since it might last anywhere from an hour to a year, so it cannot be guaranteed to work and therefore shouldn't be sold. But I can see it has it's place when there is no option, or it literally might cost you a kidney.
 

Offline AlfBaz

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Re: Which Oscilloscope to buy for Computer repair
« Reply #5 on: September 08, 2013, 01:10:23 am »
Hi, I  live in India and here we do not replace  but repair...
India and its people would have to be one of the best recyclers in the world, they waste nothing and we should all be following in their footsteps :-+
 

Offline Hydrawerk

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Re: Which Oscilloscope to buy for Computer repair
« Reply #6 on: September 08, 2013, 01:33:56 am »
Hi, I  live in India
BTW I have in my kitchen a great radio made in India. You are apparently good at electronic. It is named Olympia ATS-803A. It was manufactured probably in 1990 and it is still going strong. http://cbradio.cz/hamshack/Scanner/Olympia_ATS_803A.jpg
I still listen to it.
Amazing machines. https://www.youtube.com/user/denha (It is not me...)
 

Offline gibbled

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Re: Which Oscilloscope to buy for Computer repair
« Reply #7 on: September 08, 2013, 05:23:23 am »
Looks just like the Sangean of the same model number and my radio shack dx-440.
 

Offline Hydrawerk

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Re: Which Oscilloscope to buy for Computer repair
« Reply #8 on: September 08, 2013, 08:18:27 am »
Yes, it was sold under many brands.
Amazing machines. https://www.youtube.com/user/denha (It is not me...)
 

Offline rdl

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Re: Which Oscilloscope to buy for Computer repair
« Reply #9 on: September 08, 2013, 08:48:21 am »
I have a DX-440 that I bought new back in the late 80s from Radio Shack and a Sangean ATS-803A that I got off eBay about 6 or 7 years ago. I'm pretty sure Sangean was the actual manufacturer of these radios, and both of mine are labeled as being "Made in Taiwan".
 

Offline PedroDaGr8

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Re: Which Oscilloscope to buy for Computer repair
« Reply #10 on: September 08, 2013, 12:46:11 pm »
In india, there was a period where they decided to try to show the world they were self sufficient. Foreign companies had to team up with a local company if you wanted to make or sell anything there. A prime example is Maruti Suzuki. So it is quite possible that this company was the Indian arm of a Taiwanese company and made this in India.
The very existence of flamethrowers proves that some time, somewhere, someone said to themselves, "You know, I want to set those people over there on fire, but I'm just not close enough to get the job done." -George Carlin
 

Offline iceisfun

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Re: Which Oscilloscope to buy for Computer repair
« Reply #11 on: September 09, 2013, 11:55:42 am »
I administrate many servers and assemble/repair/maintain many server class machines

75% of all failed hardware I pull/trash has small faults that I doubt could be fixed, such small things that they are just not usable for anything important and so cheap to replace its too expensive to put a probe to a board, and so complex unless its a power issue you could spend forever just hunting.

Even older stuff is this way, I have a scope and other stuff just for fun though, its fun knowing how computers work and I'm working on a Z80 just for fun, maybe I'll do another one if I have not had enough when I'm done with the Z80 :)

If you want some old broken hardware to trouble shoot I could probably send some, I even know whats wrong with some of it.
 

Offline amyk

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Re: Which Oscilloscope to buy for Computer repair
« Reply #12 on: September 09, 2013, 06:26:08 pm »
Hi, I  live in India and here we do not replace  but repair...
India and its people would have to be one of the best recyclers in the world, they waste nothing and we should all be following in their footsteps :-+
It's much the same for electronics in China. There are shops where you can get your laptop/tablet/phone/etc. reballed and/or parts-swapped while you wait and watch.
 

Offline madires

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Re: Which Oscilloscope to buy for Computer repair
« Reply #13 on: September 09, 2013, 08:03:09 pm »
Hi, I  live in India and here we do not replace  but repair...
India and its people would have to be one of the best recyclers in the world, they waste nothing and we should all be following in their footsteps :-+
It's much the same for electronics in China. There are shops where you can get your laptop/tablet/phone/etc. reballed and/or parts-swapped while you wait and watch.

That's great! I've fixed some mainboards with bad caps, nothing fancy but much better than throwing more stuff on the huge pile of e-junk. Rare earths are so expensive that some companies are trying to figure out to extract them from e-junk. I hope we'll see some change in the future, products built to last and designed to be repairable.
 

Offline flolic

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Re: Which Oscilloscope to buy for Computer repair
« Reply #14 on: September 09, 2013, 08:24:39 pm »
For years I do laptop and game console motherboard repairs on a component level. BGA reflowing, reballing, mosfet, IC, electrolytics change... It's a good money once you gain enough experience and collect all necessary equipment.
 

Offline amyk

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Re: Which Oscilloscope to buy for Computer repair
« Reply #15 on: September 09, 2013, 10:50:24 pm »
That's great! I've fixed some mainboards with bad caps, nothing fancy but much better than throwing more stuff on the huge pile of e-junk. Rare earths are so expensive that some companies are trying to figure out to extract them from e-junk. I hope we'll see some change in the future, products built to last and designed to be repairable.
Those services are available in Shenzhen at the SEG and Yuanwang digital mall, the tradeoff is that you probably won't be getting real name-brand components. And as alluded to above, they really love recycling, so new/unused is not easy to find. On the other hand, the prices also reflect that.
 

Offline dev9393

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Re: Which Oscilloscope to buy for Computer repair
« Reply #16 on: September 14, 2013, 06:27:38 am »
If you want some old broken hardware to trouble shoot I could probably send some, I even know whats wrong with some of it.
     please let me know what .hardware it is????and thanks for the offer :). sorry if my reply is in incorrect format as i am to the forum & do not know how to high light & using the forum.
 

Offline toni31

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Re: Which Oscilloscope to buy for Computer repair
« Reply #17 on: September 21, 2013, 05:01:21 am »
but is a good buy an oscilloscope for pc and laptop repairs
i mean it's useful?
 

Offline analiachester

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Re: Which Oscilloscope to buy for Computer repair
« Reply #18 on: April 04, 2014, 11:21:40 pm »
Seriously, there's not much scope in computer repair, you would not earn enough, especially in India. If you're doing this because of interest then it's total absurd because only money matters in the society. You should contact some tech store who can guide you well,
« Last Edit: April 05, 2014, 03:06:25 am by Simon »
 

3DG4

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Re: Which Oscilloscope to buy for Computer repair
« Reply #19 on: September 08, 2015, 12:14:58 pm »
I know this is a very old thread but, I wanted to share my thoughts on the OP's question.


If you are going to do troubleshooting and repair of laptop motherboards, then an oscilloscope is certainly a requirement. You won't be measuring CPU or RAM clock speeds with a scope in this application. Don't get hung up on all the bandwidth and sample rate tomfoolery that is so pervasive in these types of discussions. ANY analog or digital scope with around 50 MHz of bandwidth (or more if you desire) will be more than sufficient for the task. In my personal experience doing laptop motherboard failure analysis (troubleshooting all the boards that level II repair techs can't figure out) a good 90% of the failures are "no power" issues. In addition to performing voltage checks on the various regulation and startup circuitry with a good multi meter, it is often necessary to analyze the PWM signals coming from the half-dozen or so buck converter driver IC's on the board. In this instance, it's more about determining if a signal is present rather than the parameters of the signal itself. Also, checking for acceptable power supply ripple level on the outputs of the buck converters can only be achieved with an oscilloscope. Another way that a scope is indispensable in this application, is observing high to low or low to high logic level transitions when the power button is pressed. I find it much easier to look at the crisp clear trace on my Tektronix 2465A going from 0V to 3V and vice versa, than watching my Fluke DMM bounce around before settling on a measurement.

Just as a side note, I would like to add that the computer repair industry is far from dead. I work for a very large company that repairs tens of thousands of laptop computers a year. Sure, not all of them are motherboard related issues, but a lot of them are. I think it's important that we try our best to give clear and accurate responses to questions that are posted here. If you don't have experience on a particular topic, don't post nonsense. By doing so you very well may be driving away future generations of nerds like us that have a vested interest in electronics.

 

Online BradC

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Re: Which Oscilloscope to buy for Computer repair
« Reply #20 on: September 08, 2015, 12:58:58 pm »
If you don't have experience on a particular topic, don't post nonsense.

You've just described 99.99% of "the internet". Wikipedia and Google experts abound.
I agree however.
 

Offline OldSchoolTechCorner

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Re: Which Oscilloscope to buy for Computer repair
« Reply #21 on: September 08, 2015, 02:03:31 pm »
You really don't need Oscilloscope to get into computer repair, it end up more likely becoming a door stop, or expensive paper weight and if you have to ask, then you don't need it.  Learn the basics first. Like how to replace LCD screens on tablets, phones and lvds connectors on mainboard, as with apple laptops to much current on one pin end up melting the connectors and shorting rail to ground, so is a common issue and then people break the power jacks, or USB mini jacks on various devices, so another common issue your come across a lot. Learn how to clone hard drives, or SSD drives and how to remove virus without having to wipe out drive, testing and replacing memory. For component repair, you need basics component knowledge and troubleshooting skill and be able to read and understand schematic diagrams as you se a lot of defective buck DC/DC controller and resistors that go bad on main board. Then you have to know how to check ESR on capacitors and absolutely need a ESR meter to start with, as they use low hour rated cheap capacitors and they go bad in power supplies and motherboards. Not all capacitors will bulge out and vent. That will cover most standard repairs. 

To do most advance repairs at component level, is where you start to making good money,  but you really do have to know what you are doing having extensive knowledge in circuit design and troubleshooting and invest in other equipment and a BGA rework station which is a whole another science to learn, as even for more common issues of crack solder balls under BGA. You have to be able to source new chips, as you can't use old one as substrate material and heat was the issue, using old chip it will just fail again and know how to set temperature profiles for ramp up and down and ETC. So you don't damage and warp board and for humidity control to get a successful replacement of the chip and reball done. One profile is different from another, as a lot of factors you have to consider when creating a good profile. I use to SMD rework by hand with just a heater with glass to use as a preheater and heat gun back before rework stations were popular. and can solder most chip by hand in seconds, took a while and ton of practice to become good and am a EE.

« Last Edit: September 08, 2015, 09:53:21 pm by OldSchoolTechCorner »
 

3DG4

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Re: Which Oscilloscope to buy for Computer repair
« Reply #22 on: September 08, 2015, 02:38:48 pm »
You really don't need Oscilloscope to get into computer repair, it end up more likely becoming a door stop, or expensive paper weight and if you have to ask, then you don't need it.  Learn the basics first. Like how to replace LCD screens on tablets, phones and lvds connectors on mainboard, as with apple laptops they pass to much current end up melting the connectors and shorting rail to ground, so is a common issue and then people break the power jacks, or USB mini jacks on various devices, so another common issue your come across a lot. Learn how to clone hard drives, or SSD drives and how to remove virus without having to wipe out drive, testing and replacing memory.
 

The OP was not talking about sub-assembly level repair of computers. They specifically stated that they were interested in doing component level repair on motherboards. Not every failure leads back to a cracked solder joint on a BGA. I suppose if you were only interested in swapping parts (shotgun troubleshooting) and re-flowing chips at random to try and fix a dead board then the advice you give might hold water. This is not the correct way to troubleshoot electronics. Again, why are we trying to deviate WAY beyond the scope of what the original question was?

understand schematic diagrams as you see a lot of defective buck DC/DC controller..........that go bad on main board.

How do you hope to accomplish this task? By replacing every chip in sight and with your fingers crossed hope that it fixed the problem? You can't substitute knowledge and critical thinking for all the latest whiz-bang technology on the planet. I'm doing my best to keep this constructive but it seems to be to no avail. When I take a motherboard that I've diagnosed to the BGA rework department to replace a chip, I do so with 100% confidence that the part in question is the source of the failure. We need to start teaching REAL troubleshooting again instead of pushing the ubiquitous spray and pray mentality. I mean no disrespect to you sir, but you are painting an all too familiar picture of this trade. As far as not needing an oscilloscope to properly troubleshoot a laptop motherboard, to put it lightly, you're dead wrong.
 

Offline OldSchoolTechCorner

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Re: Which Oscilloscope to buy for Computer repair
« Reply #23 on: September 08, 2015, 02:53:12 pm »
I have extensive knowledge and your just a your typical tech of trade and am a Engineer. So just don't guess and don't use shotgun approach and always narrow down the issue and cause of failure and know that board will work and fix 1000's of boards with various issue to component level and fix much more then just tablets and computers. Yes do have mixed signal scope, logic analyzer and various other lab gear and it needed, but also have the knowledge to be able to use the tools effectively and pretty sure you have the knowledge and training to, but not everyone does and that the point you missed.

It nice to have people learn I just can not recommend to someone just to get a scope, or any piece of test gear without getting the basics down first. Learn how components work and circuit design and troubleshooting first. You just don't buy test gear to buy it, as it then not really a tool at that point and waste of money. I don't want hacks doing repairs and guessing, as get boards all the time that someone attempted repair on and failed. Never do a simple reflow, or clamp trick, or towel and oven trick I see people do for BGA chip repairs, it will not only temporary at best if it does somehow manage to actually work and but more likely destroy the board in the process and more likely won't be repairable again. If someone starting off there also a market for basic repairs as screen replacement, power jacks replacements, data recovery and ETC on the computer repair side. Just won't make as much, as pretty common knowledge and prices of laptops and desktops are pretty cheap and live in a throwaway society.  Now if someone willing to take the time and buy the equipment and learn electronics and troubleshooting to start. Then any a good working analog crow, as they can be had cheap, or digital scope of 50 MHz and up of bandwidth will be more then enough to start with. The Rigol scopes are decent for the money.



« Last Edit: September 08, 2015, 09:54:20 pm by OldSchoolTechCorner »
 

Offline OldSchoolTechCorner

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Re: Which Oscilloscope to buy for Computer repair
« Reply #24 on: September 08, 2015, 04:05:16 pm »
We need to start teaching REAL troubleshooting again instead of pushing the ubiquitous spray and pray mentality.
I do agree with this part and that the point I am trying to get across.
 


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