Jump to content

Welcome to Geeks to Go - Register now for FREE

Geeks To Go is a helpful hub, where thousands of volunteer geeks quickly serve friendly answers and support. Check out the forums and get free advice from the experts. Register now to gain access to all of our features, it's FREE and only takes one minute. Once registered and logged in, you will be able to create topics, post replies to existing threads, give reputation to your fellow members, get your own private messenger, post status updates, manage your profile and so much more.

Create Account How it Works
Photo

Burnt spot on chip... normal or not?


  • Please log in to reply

#1
paratrewpr

paratrewpr

    New Member

  • Member
  • Pip
  • 7 posts
Howdy all,

I've been troubleshooting what appears to be a power supply unit (PSU) problem in an E-Machine computer I bought a few years back for my son. He was about 3 at the time so the fact it lasted this long kind of amazes me. Anyway, with the help of this site and a few others I saw a pattern developing where users complaining of the same symptoms mine was having turned out to all be related to the PSU. As background info, here is what was happening... it started with a few intermittent lockups that are kind of typical (I think) for a kids computer, so I didn't really put much thought into it then. Then, after a couple other weird starts and some more ominous lockups, the monitor all of a sudden wasn't getting a signal. The computer would start (or sound like it) but no signal. So today when I went to troubleshoot it I expected to just be able to use the restore CD and wipe it clean. But, it wouldn't turn over at all. No clicks, whirs, or anything.

So I pop the cover, start making the usual connection checks... make sure it has power (at least to the PSU).. check for switches that might have been flipped by my son...etc... Everything seemed fine except it wouldn't start. Checking the switch, I hot wired it... nothing. I wanted to check the power supply but there is no external switch. I suppose it is electronically switched by the motherboard that the front panel switch is routed to. It seems to me though that on these systems where the PSU switch is routed through the MB that when you plug in the power cable it makes a brief noise. This isn't doing that. So trying to find a way to hot wire the PSU (some of you cringed... I know... not a good idea but had to at least entertain the thought), I disconnected the multipin connector. Well, here's where I noticed what I think is the Bios chip that was sort of hidden behind that connector. Its got a little burn on it about the size of a pencil eraser.

Here's two pics of it ... one close up the other back a bit to get you perspective.

http://h1.ripway.com.../Bioschip01.JPG

http://h1.ripway.com.../Bioschip02.JPG


Without any luck on my own I set out to find some info on this issue. Its then I see that this PSU is linked to more than a few other issues very similar to my own... most of which ended up with a dead MB. So right now, I'm thinking that my MB is dead. I was just about to start scavenging the machine for parts but thought I might post here first to see if anyone has any thoughts on the matter. It would be nice to be able to troubleshoot the PSU but I don't know how.

Aside from the PSU issue or what might be the root cause, I'm really curious to know if that chip is burnt out or not. I've seen burnt or browning spots before on working systems and for all I know that might have been part of the installation of the chip. It just really looks fried though. I don't think the pic shows it good enough but the burn is more than sticker deep. It looks and feels like the plastic part of the chip has actually boiled up. Does that look normal?

I don't plan on putting any significant time or $ into this problem since the initial investment was sub $300 anyway. Its now just mainly a matter of satisfying curiousity. Thanks for your help.

Jeff


ps.. just noticed I could attach files to this post so I'll upload one of the pics locally so it'll be available after I remove them from the remote site.
Bios_chip_01.JPG
  • 0

Advertisements


#2
WinCrazy

WinCrazy

    Member

  • Member
  • PipPipPip
  • 324 posts
The burn indicates an internal short in the IC. Unfortunately, this cannot be repaired.

I would salvage the hard drive, floppy, if any and the RAM module(s). The rest is toast. I can only speculate that the power supply put out excess voltage and that the other components may have been damaged or weakened too.
  • 0

#3
Jack123

Jack123

    Trusted Tech

  • Retired Staff
  • 944 posts
01-Paratrewpr [Power Supply Issue on E-Machine]
29th May 2006

Aside from the PSU issue or what might be the root cause, I'm really curious to know if that chip is burnt out or not.


I would say that the Power Supply is the – Root Cause – of the problem –It appears that the power supply had 1 or more Voltages go – Out of Regulation - & drew excessive current – The Power Connector is right near the burnt chip – Probably caused an – Innerlayer Short –

The location of the burn area is usually the source of the Short Circuit – where the two tracks would be the closest – Looking at the photos – I would say that the line in question would be pins 8 and or 9 which is your [+5-SB] and [PWR_OK] pins on connector [??] – which are the 2 pins pretty much in line with the burnt area –

The Power Supply – when power is applied – goes thru a – Power Self Test – and then the +5 Standby Power will generate a – Power OK Signal – to permit all the power voltages to be applied to Motherboard – So without this +5 Volt power and Power OK Signal – The power supply will not turn on –

So the Power Supply is the root cause & the burnt Chip is the result – Not sure if any other parts were damaged – but chances are most every thing else may work for awhile – but certainly has be deteriorated/compromised – and would have a shortened life – Of course that is what happened during the earlier stages of the problem. It eventually turned – ON – but then finally it did not –

The only thing that could have prevented the loss of the Motherboard – would have been – Replace the Power Supply at the 1st indication of the problem – Of course this is hindsight – Now – but if you look at all the problems recorded – the ones that had – Early Power Supply Replacement – were the ones with success –

THE power Supply is a – Key/Critical Element – of the PC. Usually the Manufacturer will just install the bare minimum – and does not allow for upgrades – that would surpass performance -
_____________________________________________________________________________

these systems where the PSU switch is routed through the MB that when you plug in the power cable it makes a brief noise. This isn't doing that. So trying to find a way to hot wire the PSU (some of you cringed... I know... not a good idea but had to at least entertain the thought), I disconnected the multipin connector


Your right – I would cringe – but if you can make a – [Quick – Steady – ALL Pins Connected at ONCE – with no – Bounce – Connection] – Fine – But if you do not have a – Working/Functional Motherboard – or a Functional Power Supply – that passes its – Self Test – It will not Turn ON –

The damage was already done – Only if you wanted to question the earlier symptoms – at the time – then maybe the Motherboard may have been spared – Most power supplies have – Protective Circuits – some are better than others – but when they fail – then PC is in jeopardy – A Good Supply – would have included Tests for these – Protection Circuits – but then you can only go so far with a diagnostics -
____________________________________________________________________________

Good photo – I could not discover any other obvious damage – perhaps looking on the underside of the Motherboard – would show more [??]

Jack123
  • 0

#4
paratrewpr

paratrewpr

    New Member

  • Topic Starter
  • Member
  • Pip
  • 7 posts
Wincrazy/Jack123... thanks for your replies. I was afraid that was the case but at least I was on track.

Jack... heckuva answer! Great info there. And by the way, when I scavenge that system I'll check the underside of the MB and if anything is visually abnormal, I'll snap a pic and post it.

Jeff
  • 0

#5
jrm20

jrm20

    System building expert

  • Retired Staff
  • 2,394 posts
Yeah thats definately not normal lol..

Get a new mobo and you might want to get a new powersupply...
  • 0






Similar Topics

0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

As Featured On:

Microsoft Yahoo BBC MSN PC Magazine Washington Post HP