# Compaq flashing green light



## ssbumz (Dec 31, 2009)

Ugh!

I have an older Presario that I was going to install an additional HD in. Cracked it open, popped in the drive. Plugged everything back up and now it won't power up. The LED on the PSU and on the power switch flashes. That's all it does. No fans running when I hold in the power switch, no nothing but the flashing light.

Removed the HD I installed and put everything back like it was to start with. Same problem. I isolated the prob to the multi-pin connector from the PSU to the motherboard (not the 4-pin one). I can have everything else plugged in but when I plug that in, the flashing starts.

Power supply or motherboard? How do I finish the troubleshooting? Do I have to buy a PSU to got to the next step?

Thx!


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## Tyree (May 10, 2009)

Are the Hdd's IDE or SATA? Clear the CMOS, connect ONLY the older drive and try to boot.


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## delaware74b (Feb 2, 2008)

What power supply is installed in your system? Bestec's are known for failure, especially with the +5 V standby power. There is a version that is known to be a motherboard killer when the +5VSBY fails. The power supply probably has bad capacitors.


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## bdog840 (Oct 4, 2010)

I have a Compaq Presario five years old until this morning it wouldn't power on. The green light on the power supply was flashing. I've heard about power supplies going out for no reason. I took a trip to Staples and purchased a Antec Power Supply that was 350 Watts about ($47). The Bestec one that failed was 250 Watts. The Staples guy told me that it wouldn't hurt the mother board if I used a higher wattage PSU. I installed the Antec in the computer, connected all the cables and it fired up. 

A friend also told me that it is best to use a higher wattage PSU. Is this true?


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## bdog840 (Oct 4, 2010)

A lot of eMachines computers manufactured between late 2002 - 2004, even into early '05 contained the flawed Bestec ATX-250-12E power supply. This particular model has a flaw in the +5VSB rail, where the voltage will spike up to 8v, even 10v+, eventually frying the power supply itself, as well as your motherboard's chipset. When this has occurred, even after you replace the power supply, the computer will do nothing more than spin the fans when you press the power button.

I have the Bestec ATX-250-12Z model which was built with an overload surge protector that thankfully saved the motherboard. The 5+VSB (5+ Volt Stand By) rail went bad because I have been using the sleep mode since my computer was new. Older eMachines & HP have been using these poorly made power supplies if you have a Bestec I'd change it right away.


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## Muataz Jabri (Aug 12, 2011)

check the PSU for the fan then if the fan work but the system does not boot, if your HDD using IDE cable , check if the HDD is slave or master 
if you connected it as a slave and the IDE cable does not have a twist, the system will not work at all.


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## Tyree (May 10, 2009)

It is very possible the old PSU did some damage when it failed.


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