They look sad. What kind of lighting are you using? They look sunburnt. If you're using standard lighting and watering I would have to guess some kind of disease. When you say same soil, do you mean that you reuse it?
Rick

Yes I did re-use the same soil after I re-planted them into bigger containers and yes I did take them outside for a few days about 2 weeks ago we had temps in ohio between 75 and 85 degrees on the weekends. I thought that peppers plants liked heat so yes I did leave them in DIRECT sunlight a few days. Should I put them in the shade on nice days outside? Last summer I grew them in the ground all summer and never had an issue with the leaves doing this.

I left mine outside but in partial shade and not all day, but my plants were alot larger than yours. I brought them inside again as the sunlight was too strong as some of the other plants dried up a little. I would venture to say that your plants have had too much sunlight too soon. I've potted up one of my bhut jolokia's and its doing fine so far, but I'm hating the windy weather and heat that we have been seeing so far this year :(

this is called sun scald. done.

definitely sun burn. your leaves were killed by NOT hardening them off first.

Good news the plants will live. the new tiny leaves will be fine. If you planted them outdoors right now the new leaves will all grow correctly and not need hardening off because they will grow from the very first day outdoors and automatically be fine with strong light. If you want to leave them in the pots then take them outdoors all day and back indoors at night. that is what I do every day.

nitrotrain:

What I'm wondering is, is how you reuse the soil. Do you remove the soil from the pepper's roots and pot them in fresh soil - thus leaving behind the soil they germinated in? ?!?!?!

you're making this too difficult. Its just sun scald. Your soil is fine.

I too am in Ohio, put my peppers out on those same days and have had similar problems with some of the plants. This is the cause in my case.

1) The peppers dry out, wilt a bit, and this causes sunscald. No wilting = no sun scald. I've had it happen in windowsills and outdoors.

2) Light to moderate wind whipping the plants back and forth causes damage just below the soil line. The stem dies in that spot and the plant slowly declines. If you move a bit of the soil and you should see a brown shrunken area of stem, with maybe a bulge above it where new roots want to sprout. You can cut the stem off below this and stick it down in the soil and hope roots sprout in time to save the plant.

I have no trouble with all day full sun this time of year as long as the pots are saturated with water when they go out and the plants are protected from wind. It is also helpful to have the plants on the grass rather than concrete because of higher humidity.

Thanks to all for your comments. Yes it is extremely rare in ohio to top 80 degrees in the early spring. I was still wondering about the soil issue. Does everyone RE-USE the same soil or is it better to re-plant them into fresh soil.
They are NOT planted into the ground. I am going to re-plant into 10" pots eventually if they all dont die first.
Also last year I never had an issue with the leaves doing this. Prob because they were already mature when I bought them?

I mix soil from last year's pots with new soil (Pro-Mix), probably 50-50, and re-use it. There's no reason not to, unless you experienced some type of disease in the pot. If so, send that dirt to the compost pile and sterilize the pot prior to re-use.

Good Luck.

Rick