Samsung’s struggles selling smart phones have become the semiconductor’s problem now.

Shares of Sandisk plunged 14% on Monday after the chip maker said sales of flash memory used in smartphones, known as NAND, would fall short of expectations. The warning followed a similar issue disclosed last week by NAND competitor Micron Technologies (MU). Its shares lost 6% on Monday.

The problem appears to be that with Samsung’s smartphone sales lagging, the company needed fewer of the NAND chips it made for its own devices. That put pressure on the market for NAND chips overall, analysts said.

Investors had expected booming NAND sales at the end of 2014, as sales of smartphones, tablets and laptops were growing and customers were buying more storage than ever. Apple (AAPL) doubled the amount of NAND used in its middle- and high-end iPhone 6 models, for example.

Sandisk, which reports full fourth-quarter results on Jan. 21, said revenue for the quarter would total about $1.73 billion, below an earlier forecast of $1.8 billion to $1.85 billion and under Wall Street expectations of $1.84 billion.

“The lower revenue was primarily due to weaker-than-expected sales of retail and iNAND products,” the company said in a press release. (iNAND is one of the company's flash storage product lines used in mobile phones.) The company’s adjusted gross margin would come in at 45%, below earlier guidance of 47% to 49%, Sandisk said.

Analysts blamed a spillover effect from Samsung’s smartphone problems. The 2014 flagship Galaxy S5 model was a flop in many parts of the world while the company’s lower-end products were pushed out by competition from Chinese manufacturers, including Xiaomi and Huawei. Samsung is an unusual player in smartphones, as it makes its own devices but is also a leading supplier of components like memory chips to many of its competitors.

“The key problem appears to be Samsung,” FBN securities analyst Shebly Seyrafi wrote following Sandisk’s announcement. Samsung’s smartphone sales declined 4% in the second quarter from a year earlier and declined 8% in the third quarter.

Last week, Samsung said its 2014 profit would be the lowest in three years, as the once-hot mobile unit cooled off. Analysts said the component division saved the company from reporting even worse results.

Micron was the first to disclose the overflow, although it pointedly did not name mention Samsung by name.

"We also saw increasing (triple-level cell) supply from what had believed to be one of our competitors, shifting NAND production away from their own internal mobile consumption to the channel and client SSD business,” Micron President Mark Adams told analysts on the company’s Jan. 6 earnings call.

Adams termed the problem “short term” and analysts seemed to agree, at least until Sandisk disclosed its shortfall.

As a result, both companies must now hope that Samsung turns around its phone division quickly. Samsung is expected to unveil a new flagship model in March while culling lower-end models across the rest of its line-up to better compete with the Chinese phone makers.