Can I include expenses for computer repair and maintenance at my home office as maintenance and repair business expenses?

Yes, as long as the equipment was used for business.

But where is the amount of the business computer repair added? The "Enter Repairs and Maintenance Expenses" says that this applies "only if you have a separate office that's not in your home."  My office is in my home and is only used for business.  Can I deduct these expenses?

If you are self employed, you may be able to claim the home office deduction if your office is:

• Used regularly and exclusively for your business, and
• Is your principal place of business (both conditions must apply). 

Can I take the home office deduction?

To report your expenses under home office on your return:

• Log in to your account.
• Select Federal from the left menu.
• Go to Wages and Income then select Income and Expenses.
• Go to Self-employment income and expenses and click start.
• Select Edit next to your line of work .
• Scroll down to Expenses and select Add Expenses for this work
• Select Home Office.