PC power supply effect on memory report

March 1, 2004 8:29 AM

PC hardware problem: I recently had my power supply replaced and now the computer now only reads half the RAM it actually has plugged into it...

The full story: I moved into a new apartment in an old building, and my power supply died on me. I took it to a computer shop to be replaced and they took out my generic 400w jobby and put in a 300w Sparkle. It seemed to work okay after that, but a bit slow. I checked the RAM and it only read 256mb of the 512mb. I switched it into a different slot, and it came up as 512mb again... but only briefly. Recently it's gone back to reading 256mb. I've looked around for answers via Google, but got nothing too helpful.

Some facts: 1) This is not new RAM. It's what came with my PC when I originally got it. 2) Running Win98 3) I regret taking it to these knobs, and really don't want to have them touch my PC again.

posted by picea to computers & internet (4 comments total)

Is your system loaded up with multiple drives, add-on cards, etc? Maybe 300W is not quite sufficient...

Try disconnecting unnecessary drives. If the memory starts working again, then you probably need a more potent supply.
posted by Galvatron at 9:07 AM on March 1, 2004

There's a big warning sign coming in your first line, hardware randomly dying when you just moved could very well mean you moved to a building with dirty power.

This is a lot more common than you might think, building with power that fluxuates a lot. This is hell on computer parts and can cause all kinds of failures.

Surge protectors do nothing for this, you should immediately look into a line conditioner like this one. You can get UPSs with a line conditioner built in, but the important thing is to clean up the power coming to your computer.

I've seen hard drives, monitors, and PSUs die from dirty power.

Now, all that said, here are the possibilities:
1. Your RAM got fried with the PSU
2. Your RAM got knocked loose in transit, pop open the case, eject both sticks of RAM, and re-seat them.
3. Your new power supply insufficient to power your system (see galvatron's advice above).

For future reference, replacing a power supply is a pretty easy thing to do.
posted by malphigian at 9:12 AM on March 1, 2004

The dirty power scenario is frightening. Is there anything a building owner can do to alleviate this without major rewiring? Or is there a way to prove it's occurring? See, the warning bells went off for me too, because that's a hell of a coincidence that the PC would just happen to crap out after I moved. I couldn't figure out how to prove it that something was amiss though, because there's an office downstairs with PCs that seem to run fine.

Thanks for the advice, Galvatron and malphigian. These are good leads and possible solutions.
posted by picea at 9:36 AM on March 1, 2004

Remove the memory, dust the slot with pressured air, put it back in.

Probably just not seated properly, or maybe has a bit of corrosion on the DIMM slot.

Otherwise, bad luck, your POS PSU fried some parts. That's why I tell people:

"Cheap PCs hold fire risks".

And they can blow up all your parts too (it's all the crapola PSUs most people save $40 on. With a PSU, if it ain't heavy, it's junk.)

Last, but not least, wattage ratings on all but the top of the line PSUs are a load of bunk. I've seen double stickered PSUs which have multiple ratings on them, depending on what stickers you peel. And then, inside, beside the fuse, is the true rating of the 350 watt generic PSU... "180 watts". Yuck.
posted by shepd at 12:27 PM on March 1, 2004