Authorities in the US and South Korea are investigating why even the replacement Note 7 phones that Samsung equipped with a safer battery reportedly caught fire.
An official at the South Korean safety agency said the replacement phones might have a defect that was different from the problem with the original Galaxy Note 7s.
'Brand damage'
Samsung could suffer "a considerable loss of consumer faith," said Greg Roh at HMC Investment Securities.
"If it's once, it could be taken as a mistake. But for Samsung, the same thing happened twice with the same model," he said.
"The reason consumers prefer brands like Samsung and Apple is because of product reliability. So in this case, brand damage is inevitable and it will be costly for Samsung to turn that around again."
At least five fires were reported in replacement devices in the US.
Samsung said it had sold about 45,000 Note 7s through pre-orders in Europe.
The handset was never released for sale in the UK.