|Congratulations on your expected new arrival. |
Hopefully you didn't touch the computer with a vacuum cleaner? That can damage the components from static discharge.
I suggest you go to your nearest office supply and get a can of compressed air and use it to blow out the dust from the insides of the case. Include blowing out the power supply from both ends. This will be messy, so you may want to move the tower outside.
Next, re-seat all the connectors, memory cards, etc. Don't just push on them. remove and re-seat. When dealing with the RAM you can snap each one in and out 4 or 5 times. This is to burnish the contacts.
If you moved the fan that sits on top of the CPU at all then you need to remove the heat sink/fan assembly. Clean off all thermal residue and apply new thermal compound sparingly.
Try running the computer with the card reader disconnected from the motherboard. Is the connector for the card reader a single connector or multiple connectors?
Can you post the model of the computer here?