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View Full Version : Mike's Diagnostic Rant



mbbrutman
September 17th, 2006, 06:27 AM
I cringe when I see bad or incomplete information. A recent thread has made me cringe a lot. Here are the things that have gone wrong so far:


Sounds like a PSU problem. You said the fan turns. Does it turn indefinitely or just budge?

PSUs are highly reliable, except in the hands of certain people who chew through them on a weekly basis.


I recommend to get PSU out and heck with old hdd (one, that is not expensive). If it will turn up you can eliminate PSU.

Another knock on the PSU. Before telling people to get rid of PSUs and hard drives we should be telling people who to tell if their PSU is bad.


Would be good if you meansure voltages from PSU.
Remember, that something must be connected to the PSU.

Ok, this is getting better - we are starting to talk about testing the PSU. Except that it is incomplete. The PSU needs a load, but why and what? A floppy drive won't work. A hard disk is the usual 'test load', but the motherboard draws enough load to test the PSU as well.

These machines were designed without a hard drive. Instead of unplugging everything from the PSU, one can easily leave the PSU in place and connected and just probe the voltages from another internal power connector. That limits the potential for mis-handling/damage.

And along with the advise to measure the PSU, there should have been a pointer to go see the Tech Ref for what to measure.


Temporary remove all cards exept video adapter. Reseat all chips in sockets on motherboard.

Without a working monitor the video adapter isn't going to show much. And the fault could be in the monitor or the power to the monitor, which involves a different test (involving AC) on the PSU. Before tearing a machine down I'd have eliminated other, less intrusive possibilities.

Also, reseating chips is risky. You are possibly exposing them to physical damage from being handled, and static damage. That should have been pointed out, especially since most people don't know how to take precautions against static. (Which explains a lot of flakey hardware, both old and new.)

Nobody bothers to explain what the user will expect when the machine is stripped down to just a video adapter. What's the usefulness of giving a diagnostic procedure without outlining the correct output?



You know, this is just be ranting. But I think I know a bit about these machines, and machines in general, and it pains me to see a newbie risking unnecessary damage because of bad advice.

- Find out all of the symptoms first. Explain what is supposed to happen, especially if the person admits to being a novice.
- Don't just start blaming obvious parts and part swapping. Consider all possible problems. In this case the monitor might be the problem. We don't know enough because we don't know how long the person waited for the boot to complete.
- Don't give advice without explaining why. If you are telling somebody to perform a diagnostic procedure explain why, and what the intended outcome is.
- Caution people to use proper care, including the correct tools. They might be novice users and not be aware.
- Don't recommend invasive procedures until the less invasive ones have been explored. The more you touch, the more risk you take.



I'm here to spank people. You can reply back and bitch me out if you want, and we'll discuss it. But let's not do people a disservice by handing out bad or incomplete advice.

Unknown_K
September 17th, 2006, 07:48 AM
I think just about all repairs on newer systems are just part swapping until the problem goes away, parts are cheap and repair sites are not (go see what bestbuy wants to install a new HD).

The reason power supplies are being blamed for everything these days is because most people buy cheap systems or cheap cases with a very under rated PS and then load them up with power hungry P4's, multiple burners, multiple hds, and power hungry gamer video cards. Another reason is the PS are rated for that output if they run cool, all the case heat gets sucked over the PS does not help the situation.

carlsson
September 17th, 2006, 08:36 AM
What Mike forgot to mention that the comments referred to fixing an IBM 5160, so not a "newer" system and definitely not a power hungry Pentium 4.