Heatmap, and heatmap.2 gave different figures for the same dataset

I have a huge dataset(15k X 18) and tried to use the heatmap in R to examine the patterns. However, I found that heatmap and heatmap.2 gave me completely different outputs.

Here are the codes:

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dim(as.matrix(data.dcpm))

[1] 15462??? 18

heatmap(as.matrix(data.dcpm), col=topo.colors(100))
heatmap.2(as.matrix(data.dcpm), col=topo.colors(100), key=TRUE, density.inf="none",trace="none", scale="none")

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The outputs are attached here.

Could anyone help me figure out why?

Thanks a lot:)