Try assembling the system outside of the case, could be a short when it's in the case.
Main Topics
Browse All Topics
Loading Advertisement...
Question
Trying to fix a PC.... should I just give up?
I have some elderly neighbors that I'm trying to help out. They had a PC die on them.
It was put together by a local clone shop. It had an Asus A7N8X-X and an Athlon XP 2700+.
The thing just would not power up. I tried it with a known good power supply and it still would not power up (the LED on the board would light up when power was connected). I figured it was the motherboard so I got a A7N8X-LA off of ebay. It's the same motherboard except smaller (same chipset and the like). I plug the new board into the known good power supply and get no activity. At this point, I figured that it was a bad CPU. I borrowed a XP 2800+ from a friend with no positive results. I tried the power switch jumper on all the control panel pins just in case, but still no love. I thought there might be something wrong with the power switch, so I salvaged one out of another case with the same results.
So basically, I have a new board, a working power supply, and a different CPU and can not get so much as a spinning fan. I'm about ready to give up. Anyone have any ideas before I tell them to bag it?
Thanks!
This Question has been solved and asker verified All Experts Exchange premium technology solutions are available to subscription members.
Subscribe now for full access to Experts Exchange and get
Instant Access to this Solution
- Plus...
- 30 Day FREE access, no risk, no obligation
- Collaborate with the world's top tech experts
- Unlimited access to our exclusive solution database
- Never be left without tech help again
Trusted by hundreds of thousands everyday for fast, accurate and reliable tech support.
- "The time we save is the biggest benefit of Experts Exchange to Warner Bros. What could take multiple guys 2 hours or more each to find is accessed in around 15 minutes on Experts Exchange." Mike Kapnisakis, Warner Bros.
- "Our team likes having a resource that is more secure than just using Google and most experts using this service really know their stuff. It's nice to look here first versus using Google." Dayna Sellner, Lockheed Martin
- "Anytime that I've been stumped with a problem, 9 out of 10 times Experts Exchange has either the accepted solution or an open discussion of the potential solution to the problem." Kenny Red, eBay Inc.
See what Experts Exchange can do for you.
Got a question?
We've got the answer.
Experts Exchange has been collecting answers to technology questions since 1996…3 million and counting! If you have a question, chances are we already have your answer.
Need individual assistance?
Our experts are ready to help.
If you can't find the exact answer you're looking for, ask our exclusive community of 50,000 experts. You’ll get a personalized answer from a trusted professional.
Want to learn from the best?
Read articles from industry experts.
Thousands of free tech tips, tricks, how-to’s and tutorials are available in our peer reviewed articles section. See for yourself how smart our experts are, no login required.
Working on a long term project?
Store your work and research.
Save solutions to your questions, answers you’ve discovered through searching plus helpful articles in your personal knowledgebase for easy future access.
Access the answers to your technology questions today.
30-day free trial. Register in 60 seconds.
What Makes Experts Exchange Unique?
Members of the expert community talk about why the experience at Experts Exchange is different than what you will find anywhere else.
Trusted by the world's most respected brands.
Faithfully serving IT professionals since 1996.
Try it out and discover for yourself.
30-day free trial. Register in 60 seconds.
Free Tech Articles
-
WARNING: 5 Reasons why you should NEVER fix a computer for free.
It is in our nature to love the puzzle. We are obsessed. The lot of us. We love puzzles. We love the challenge. We thrive on finding the answer. We hate disarray. It bothers us deep in our soul. W...
-
SCCM OSD Basic troubleshooting
SCCM 2007 OSD is a fantastic way to deploy operating systems, however, like most things SCCM issues can sometimes be difficult to resolve due to the sheer volume of logs to sift through and the dispe...
-
Migrate Small Business Server 2003 to Exchange 2010 and Windows 2008 R2
This guide is intended to provide step by step instructions on how to migrate from Small Business Server 2003 to Windows 2008 R2 with Exchange 2010. For this migration to work you will need the fo...
-
Create a Win7 Gadget
This article shows you how to create a simple "Gadget" -- a sort of mini-application supported by Windows 7 and Vista. Gadgets can be dropped anywhere on the desktop to provide instant information, ...
-
Outlook continually prompting for username and password
There have been a lot of questions recently regarding Outlook prompting for a username and password whilst using Exchange 2007. There are a few reasons why this would happen and I will try to cover t...
-
Backup Exchange 2010 Information Store using Windows Backup
There seems to be quite a lot of confusion around the ability to backup Exchange 2010 using the built in Windows Backup feature. This stems from the omission of this feature prior to Exchange 2007 s...
Cloud Class Webinars
- Avoiding Bugs in Microsoft Access
Alison Balter takes and in-depth look at avoiding bugs in Access. In this webinar you will learn about using the immediate window to debug your applications, invoking the debugger, using breakpoints to troubleshoot, stepping through code, setting the next statement to execute, ...
- Top 10 Best New Features in Visio 2010
Scott Helmers gives live demonstrations of the top 10 new features in Visio 2010. This webinar will teach you how to create compelling diagrams by adding shapes to the page with a single click, linking the shapes in a diagram to data in Excel (or SQL Server, or SharePoint), ...
- IT Consultant Business Secrets Revealed
Michael Munger, Experts Exchange tech pro and IT consultant, pulls back the curtain on his very successful businesses and answers question on every IT consultant and business owner should know about. He shares secrets on what he did to solve the 5 most common problems in IT, ...
- Disaster Recovery and Business Continuity
Quest CTO, Mike Billon, gives an overview of the steps involved in building a dunamic disaster recovery plan. Through case studies and an examination of software/hardware tooles for monitoring and testing, you'll gain a better understandin of where you are, where you want ...
- Organize Your Visio Diagrams with Containers and Lists
Scott Helmers uses cross functional flowcharts, wireframe diagrams, data graphic legends and seating charts to teach you: how to ustilize all three new structured diagram components in Visio 2010, the best practices for organizeing shapes in previous version of Visio, how to organize ...
- How to Us Objects, Properties, Events and Methods in Microsoft Access
Alison Dalter gives an in-depbth look at objects, properties, events and methods in Microsoft Access. In this webinar you will learn about using the object browser, referring to objects, working with properties and methods, working with object variables, understanding the ...
Join the Community
Give a Little. Get a Lot.
Join the community of experts here and help other tech pros by answering question in your area of expertise. You can earn FREE access to all Experts Exchange's premium features and resources.
Answers
I'm very experienced in the matters of PC repair... I was just looking for suggestions from other people that are likewise experienced.
Like I said... there is no power... no fans... no POST. There is an LED on the old board when it's plugged in and no LED exists on the newer board.
I did change the CMOS clear jumper....
Did you happen to hear any tones out of the motherboard speaker when you tried to boot? These will usually clue you in to the source of the problem. I assume that there were no alarms since you did not mention them.
I assume then that either power is being interrupted before it can reach the BIOS (which means a bad board, these things happen even on new boards), or that the switch or its connection is faulty. If I think there is a problem with the switch, I usually use a small piece of wire (copper is best, but a paperclip may work) to short the power pins together. When trying this, PLEASE use only one hand so that you don't conduct the electricity across your chest.
Please post the results of this test or the tones if you hear them and we can move on.
I actually have not had any ram in any of the slots during any of this. I expect the machine to power up and give me a memory missing beep code, but this does not appear do anything to attempt to power on. I did try it with the memory chips in once when I went through the trouble of mounting the board inside the case.
I did notice that when the power supply is plugged in, the BIOS chip gets warm, but there is no indication of booting anywhere.
The old board has a spot for a PC Speaker jumper and it provides no sound. The new board has a little speaker mounted to the board... no sound from it either.
It sounds like power is getting to the board due to the LED being lit (on the old board) and then BIOS chip getting warm.
Since there is no sound coming out of the system speaker, then I speculate that either the switch is not functioning correctly or the motherboard is faulty. If shorting the PWR pins does not work, then I would recommend trying a third motherboard (if it's worth it).
Short of that, I'm fresh out of ideas to save this system.
Some A7_ no post issues are resolved simply by clearing CMOS.
Not completely sure why.
Asus _7_ and to a lesser degree _8_ series motherboards are notorious for bad capacitors.
It's random about which specific models but many of them have problems.
Bad caps on Asus A7N8X-E
http://www.badcaps.net/for
Bloated Nichicon HM on A7N8X Deluxe
http://www.badcaps.net/for
Fujitsu Hybrid Polymers known to bloat on Asus A7 boards. (Poster repairs 100's of boards a year)
http://www.badcaps.net/for
Bloated Nichicon HM on A7N8X v1.04
http://www.badcaps.net/for
Usual suspects on these boards are.
Nichicon HM and HN series with date codes from 2001 thru 2004
Chemicon KZG series, can't handle heat, don't always bloat when bad
OST, don't always bloat when bad
Fujitsu Hybrid Polymers, bright yellow with black markings, not true polymers
Misc el'cheapo brands that bloat.
Once you get over the phobia of replacing parts on a motherboard it isn't that hard to do caps.
Sourcing the correct kind of caps is moderately difficult until you know something about caps.
.
Hi did not have time to double check on the specs of the motherboards, but you never mentioned video card? Is it integrated in the motherboard?
A PC would not start for four reasons only:
-motherboard
-processor
-video card
-memory
If the power supply is failing, it might still actually start and turn off in seconds, but there will be some boot activity
Is the fan starting at all?
If the motherboard and processor are ok, then the fan should start spinning and then you go to the point to get error code beeps for missing memory/video cards. Just note that some motherboards depending on BIOS dont produce sound. I got a incompatible memory for Asus motherboard once(wrong latency) and if it wasnt for the screen being connected to tell me that: "I overclocked", I would have no idea why the computer was not starting(the fan was starting though). Just went into BIOS and changed the settings for the SPD to manual and the latency to one the motherboard supports. Computers are sometimes more complicated than simple fitting of parts together. So connect the monitor if fan starts and watch for signs.
If the fan is not starting, then you have a motherboard, cpu, powersupply, power cable, electrical socket, power button issue. I narrowed it down, ha, ha.
lol... no fans... nothing!
No beeps or fans. The cpu fan has an LED and it does not light up along with the fan not spinning. Sometimes flipping the switch on the power supply would make the cpu fan LED blink and the fan nudge (showing that it would be spinning if it was working), but that's all it ever does.
The fan spins when +12v is available to it.
It doesn't care is the CPU or the rest of the Mobo are okay.
If the CPU or Mobo are bad that can stop the fan by way of protective features turning the PSU back off but if that's the case you should at least see the fan 'kick' and then stop.
If there is no fan spin at all then you aren't getting +12v 'to' or 'thru' the motherboard at all.
Usual causes are bad power supply or shorted motherboard caps.
Unusual causes are +12v shorts in drives, video card, or motherboard MOSFETs,,, a burnt PSU to mobo connector,,, or a short [usually mobo] to the chassis.
There can also be grounds in other voltages that keep the PSU from coming on.
At this point I would borrow a known good PSU and see if it will start.
Also try with minimal system.
Disconnect everything from power and motherboard - except:
Keyboard, one RAM module, what's needed for video, CPU.
You should be able to get into the BIOS or to a 'no OS' type error if you have removed the problem device.
It is advisable to do this on a piece of cardboard on a table [build system without the case] to eliminate the possibility of chassis grounds causing the problem.
.
When the computer is connected to power,the power supply starts for a second and it first sends a signal to the cpu to check if it is ok to proceed. Which means that if the mobo or cpu are not functioning, no boot will happen and the power supply fan might or might not spin.
Dying power supply will more likely have enough left to spin its fan and wake up the cpu.
In this case it does not start at all, so fault is more likely cpu, motherboard,
That's not how it works.
-
Power on PSU and chipset (by way of +5vsb) begins continuously resetting CPU.
Voltage has ~50 milliseconds to be within ~80% of nominal. [Varies by ATX spec.]
If it's not there in time the PSU shuts back down. [This is a safety feature. No power to bad mobo.]
If it is there in time the 'Power Good' signal is issued and PSU stays running.
Now is when fans start.
Now is when chipset stops resetting CPU and the POST begins.
[ALL of that happens in <50 milliseconds.]
3 Ways to Join
Business Accounts
- Perfect for organizations
- Multiple users
- Save over 36%
- Create a Business Account
Answer for Membership
- Earn free access
- Showcase your knowledge
- No credit card required
- Sign Up to Answer
Loading Advertisement...
by: lovylove143Posted on 2009-04-07 at 20:10:23ID: 24093673
How can u figure out the exact problem.... When u start the pc it there any display on screen if no check for onboard display... try cleaning ram... or at last take to some good repair shop...