Power on secuence on motherboard?
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GTP
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Was that answer of yours with irony or true desire of helping? Google searching is too limited on what I'm looking for, or maybe I don't know how to search correctly?
GTP
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Maybe both but in good faith. Sometimes you can get pointed in the right direction from random input.
"Auntie Google" can be fussy at times.
"Auntie Google" can be fussy at times.
britechguy
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I cannot count the number of times where the use of "stepwise refinement" was key to getting the focused results I'm looking for. Getting a good result from a web search virtually always means starting with an overly broad and short set of search terms, looking at what comes back, junk in particular, and adding search terms to eliminate specific words completely, force the presence of others, and add more that narrow the results returned.
One can become incredibly good at this with just a little practice. And any tech, in particular, had better learn the skill and learn it well, cause they're gonna need it, repeatedly. It's rare that more than three refinement cycles are necessary, though there are very rare occasions where it takes a lot more.
In 2021, being able to "Google it," and knowing how to do that pretty darned well, should be a deeply honed fundamental skill for anyone in this business.
Markverhyden
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@britechguy is correct. Altering the search string often brings more/better results.
There is no standard motherboard so there is no standard power on sequence. So you're dealing with trying to get the schematics for every motherboard you encounter.
I understand your interest in component level repair. But you might also consider why there is so little easily accessible documentation. No money to be made. If you business doesn't turn a profit you won't have a business for long.
There is no standard motherboard so there is no standard power on sequence. So you're dealing with trying to get the schematics for every motherboard you encounter.
I understand your interest in component level repair. But you might also consider why there is so little easily accessible documentation. No money to be made. If you business doesn't turn a profit you won't have a business for long.
britechguy
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The funny thing being, when it comes to web searches (regardless of search engine), most often more is not better. My battle, in most cases, is to eliminate rafts of stuff I don't want so that there's a better chance of finding what I do.
Of course, there is always an exception or many exceptions to any generality.
GTP
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Quite often I've been stuck with a problem, quite often not "computer" related and I've found that by reducing the amount of words in the search finds different results. Conversly, adding more words and even sentences will lead you somewhere you didnt even think of.
Wolfram Alpha is a good example of how this works.
Wolfram Alpha is a good example of how this works.
britechguy
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There is nothing like trial and error to learn this. There is nothing but trial and error that will teach you this. And you have already received a brief master class in precisely what has to be done. It's a matter of practicing doing it. And you do get better with time.
This is not rocket science. It's using search terms much like one uses different mesh coarseness in strainers. The more terms and operators, the finer the mesh, and the less of the detritus gets through. But you often need to let the detritus get through initially so that you can decide what might be intriguing that you'd like to keep that you'd never have thought about.
phaZed
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I think you're facing a large undertaking to accomplish your task, especially if you're starting from near-zero. It's not that you can't do it (you can!), however, it's that the "everyday motherboard" is the culmination of many fields and specialties. Depending on how proficient you want to be, "fixing things" will require a further and further fall down the rabbit hole.
Basically, you want to know about and have a fair to good understanding of:
Electrical Engineering - How resistance, capacitance and inductance interact with power.
- Resistors, Capacitors, Diodes, Coils/Transformers/Chokes, Transistors, MOSFETS
- Digital communication - CMOS logic, SPI, I2C, etc.
- PCB Design and layout, Soldering, Solder re-work
- Programming, binary, PIC microchip programming, Arduino, ESP8266(ESP in general)
- learn to handle these things and you will have a better understanding of the type of stuff going on in a MB.
It's a huge field - those are huge fields in and of themselves usually demanding years of schooling or "natural interest"... but those keywords will help.
You're going to need test equipment such as a DMM(Digital Multimeter, get a good one) and a digital oscilloscope - and you'll need to know how to use them.
You're going to need to have a GOOD soldering iron with different tips, a hot-air rework station and likely a board preheater depending on what you plan on doing.
Electronics Channels on YouTube that I frequent:
Louis Rossman Macbook repair videos
EEVBLOG
Contextual Electronics
mikeselectricstuff
Fran Blanche
HACKADAY
RSD Academy
Tanner Tech
Afrotechmods
Applied Science
Gerry Sweeney
Jeri Ellsworth
mjlorton
The Signal Path
w2aew
The thing is, everything works "the same"... it could be a microwave oven or a computer - the concepts are the same and once you understand Electrical Engineering you can understand virtually anything "electrical".
I would agree with some of the others' comments - much of the time, it's a waste of time to fix customer motherboards. That being said, many times you can fix a motherboard fairly easily if you know how to look for the problems (but it requires a steep learning curve - and schematics!).
As motherboards go, much of the time the damned thing is just "bad" - due to failed IC (Integrated Circuits) or bad soldering (that you will need hours and hours with a microscope to find, if you can). The other half of the time is failed BIOS's that will need replacement or reprogramming off-board (so you'll need the requisite programmers and ROMs, etc.
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britechguy
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phaZed
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Nah, not really. The programmer is like $15-$30 and I can have a BIOS chip off in 20 minutes or so. Programming takes 3-5 minutes - it's finding/having the ROMs in order that's the trick. New BIOS chips are only $10-$50 - sometimes it is easier to buy a pre-programmed BIOS chip if it's available. If you have the programmer, save the ROM for next time.
phaZed
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I'm not sure as per the volume, I don't track it that way - I only track board repairs as a whole (any problem that requires board level repairs). On a low end we might get 5-10 board repairs, 20 on the high end, per month.
If I had to guess, I may only get 20-30 BIOS chip issues per year (replacement or reprogramming).
Well, sure, if you simply replace the board as a whole every time and don't do a low-level on it, I doubt you would pinpoint the problem to such a thing... hence, you wouldn't replace many ROMs/IC's. If you don't do soldering work, you're not going to be replacing BIOS chips, etc.
Mmm, no, sorry it doesn't really work that way. The programmer is virtually universal for SPI EEPROM which happens to include most modern BIOS chips. All you need is a CH341A SPI programmer for $15 with adapters/cable/clip with it. The software has definitions for almost all SPI chips, not just BIOS's.
Amazon.com: Usb programmer ch341a, CH341A USB Programmer + SOP8 Test Clip + 1.8V Adapter + SOP8 to DIP8 Converter Module : Industrial & Scientific
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The ROM's don't really go "obsolete" - they are made for specific motherboards and versions of motherboards (1.0, 1.2, etc) for a specific laptop, or OEM desktop. No matter how old that laptop or desktop, the BIOS ROM is still as viable as when it shipped, so it doesn't go "obsolete". It's enough to get the system running and booting, you can update from there. The ROM for a Lenovo YOGA 520-14IKB is always for and ONLY for the YOGA 520-14IKB.
Many times you can try reading the BIOS while it's in-circuit, which takes like 10 minutes to check. If the BIOS doesn't read back at all or produces all FF's or 00's it's probably bad, but you have to remove it from circuit to be sure. If it still doesn't communicate or produces garbage output then try reprogramming, otherwise try a replacement.
Want a preprogrammed BIOS ROM? All over ebay for $15-25 for a YOGA:
BIOS CHIP Lenovo Flex 5-1570 (Type 80XB), Yoga 520-14IKB, 320S-14IKB, 320S-15ISK | eBay
Flex 5-1570 (Type 80XB), Yoga 520-14IKB (Type 80X8), 320S-14IKB (Type 80X4), 320S-15ISK. BIOS CHIP for Lenovo 320S-15IKB (Type 80X5), 520S-14IKB (Type 80X2), Flex 5-1470 (Type 80XA). Flex 5-1470 (Type 81C9), Flex 5-1570 (Type 81CA),Yoga 520-14IKB (Type 81C8), 320S-14IKB (Type 81BN),320S-15IKB...
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NJW
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If you watched the videos I linked to here, you would already have a good understanding of the general principles – which is all you need, really.
You can't learn everything about every possible situation and you can't somehow gain a lifetime's experience in a week or two – certainly not from a book or even a Google search. As @phaZed said, it's a huge field and you'll never stop learning. For me, the best approach is just to learn about what's on the bench right now, make notes, be prepared for next time. I'm building on over 50 years of electronics experience, but I still have to put the time in to learn about new stuff.
britechguy
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And, over time, at least for me and not just in IT, it all starts to become the next variation on a very well-known and long-established theme.
There's very little that's truly revolutionary, and almost everything else is evolutionary, allowing your existing knowledge base to serve as the foundation and that new bit is just the next "brick in the building under construction."
NJW
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Indeed, not forgetting the cyclical – the stuff that just comes around again years later.
The greatest advantage of experience, is having an understanding of what must be learned and what can just be glossed over. Rarely do all the fine details have to be even known, never mind understood. To extend the construction analogy, it isn't necessary to know how to make the bricks, just that you need bricks.
britechguy
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