No power on HP Pavillion after memory add

[LitlBob]

Hardware:
HP Pavilion a430n
1 - 512 M DDR PC2700
Supposed to support up to 2Gb.
250 Watt power supply
Working fine when I started

Decided to add additional 512 M to 2nd slot. Installed PNY D512MPPC27OPT and reassembled case.  No power.  Power supply has led that should light solid but fast blinks.  I removed new memory but PS light still blinks. I removed all pci cards but no change.  PS led lights normally only if I unplug motherboard power connection.  Plugged PS into second motherboard and led lights correctly but I don't have peripherals to test a real boot.   I've never had problems on other computers adding memory.  HP says warrantee expired 3 months ago.  This sound like a motherboard problem or flaky power supply?

Ideas?  Thanks.

[Cary_GRant]

Hi Bob,
I hope i can help. First off, 250W PSU seems kind of on the low end. But if your system was working fine before you added the new ram, then i strongly would tend to think it's either the ram itself OR the ram slot. Though your initial assumption of the power supply can also be correct since if you have lets say, 2 cd drives, a floppy, a myriad of usb devices etc, then it might have overloaded the psu itself. Have you checked to see if the powersupply has a reset buttun or breaker switch on it? Usually located near the fan up top on the rear of the system. If you have tested all the ram chips in another pc, and they are ok, then for sure its the motherboard "DIMM" slots or the PSU itself. Without a Multi-meter to actually take voltage readings, thee is no way to tell for sure. Google "memtest" and that should help determine if your ram chips are ok. Keep us posted on what you find.

[Raptor]

Be certain the memory modules are firmly seated.

Is the memory compatible with HP computers?

[merlin_2]

Visit hp website for clearing the bios.........normally take out the cmos battery?

[LitlBob]

I spoke with PNY about the memory and they were pleasant but hadn't heard of a similar problem. I tried memory in another computer and it worked.  PNY said the additional memory should take about 5 watts.  Reset CMOS but no help.

Resolution:  Installed an Antec 350 watt power supply.

Thanks to everyone for their suggestions.

[Raptor]

A minimum of 300 watt is recommended for modern computers.