PC failure - diagnosis?

[zachman93]

Usually am unable to boot PC; fans and lights run but not response on monitor. Sporadically boots past POST, fails on IDE detection and then displays message "Disk boot failure, insirt system disk and press enter." When these sporadic boots to disk error do occur, the display is wavey and "dances" unstabally.

Have checked with all components reseated, essentials only, managed a few times to get unrecognisable long-beep code (Phoenix BIOS). PSU seems fine (only about 1.5 years old), reseated CPU (paste still tacky), cleared CMOS battery, etc. The tallest capacior I could see on my board appeared to be bowed slightly at the top and had some brown substance dried to it, which I removed.

Just want to confirm that these symptoms are characteristic of a mobo capacitor failure before I move on to purchases. The capacitor appeared that it may have failed, but for all I know from past observation the brown substance could have been glue or thermal paste. If anybody could confirm or deny this as a likely cause, I would feel much better about paying for repairs or replacements.

[mjc]

The tallest capacior I could see on my board appeared to be bowed slightly at the top and had some brown substance dried to it, which I removed.


If it weren't soldered to the motherboard, that capacitor would be pushing up daisies...

[zachman93]

So I can basically confirm a mobo failure (I don't trust myself to replace a single cap)? It doesn't make sense to me that a failed capacitor would sometimes allow boot to POST, but then again, I don't know what I'm talking about. I'll take your word for it!

Could you run me down on the steps I need to take to assure that a new mobo is compatible with my PC? About 6 years old so I doubt they make the same one anymore. I'm guessing I need same peripherals, BIOS manufacturer... anything else?

Oh, and on a side note, as far as I know, my PC (Compaq Presario SR1650NX) has never had CLRTC jumpers and worked fine before this stared occuring. Just interesting.

[mjc]

I would not even bother trying to 'repair' that one...basically you would need to find an exact replacement motherboard...and that runs around $100. But everything else is also that old...which for your hard drive means about 2 to 3 yrs beyond 'average' life expectancy. The power supply, for a Compaq, is about 4 yrs beyond LE. And there is the fact that everything in it is several generations behind 'current'...not 'bleeding edge'. It's not an if another component will fail, but rather when WILL the next one fail.

As to how it can sometimes boot...I'm guessing the capacitor is only 'mostly dead'...so it's best to go through it's pockets, looking for spare change...

[zachman93]

Okay, thank you!

If you had to recommend a desktop (tower only) under $350; and a notebook in the same range, which come immediately to mind? Want to get some opinions.

Jobless and hoping to get this out of savings =(.

[hackerballs]

I would check on craigs list or the papers as you might pick up a deal for $350 as buying a new one is usually more than that.....

[66miranda]

yup, check on the craigs list first.

[larrymoencurly]

The tallest capacior I could see on my board appeared to be bowed slightly at the top and had some brown substance dried to it, which I removed.

Just want to confirm that these symptoms are characteristic of a mobo capacitor failure before I move on to purchases. The capacitor appeared that it may have failed, but for all I know from past observation the brown substance could have been glue or thermal paste.Glue is common on capacitors inside power supplies, but I've never seen it used on a motherboard capacitor. However the bowing is a sure sign that the capacitor is bad and has to be replaced because it's not working as a filter any more. The other capacitors of the same type (colors, dimensions, capacitance, voltage, brand, model) and near it are probably on their way out, too, and caps can be bad without bowing or leaking. Badcaps.net has very good information about replacing them and also sells quality caps.

[Whyzman]

Okay, thank you!

If you had to recommend a desktop (tower only) under $350; and a notebook in the same range, which come immediately to mind? Want to get some opinions.

Jobless and hoping to get this out of savings =(.What do you primarily use your computer for??

[Roxon1366]

Here's a thought... I had a similar issue with an old computer of mine... It was a faulty IDE cable... you could always try that and see if it works before you buy a whole new computer.

[mjc]

Roxon1366

The tallest capacior I could see on my board appeared to be bowed slightly at the top and had some brown substance dried to it, which I removed.

Those are the very obvious signs of a faulty capacitor...and on a motherboard, the largest ones are usually in one of the power supply lines or areas like the drive controllers. Both of which lead to very erratic performance from the motherboard...