High-Speed E8 Shinkansen Trains Set to Commence Service Again by JR East
Following a malfunction issue identified on June 17, 2025, East Japan Railway Co. (JR East) has announced that it will gradually resume operations of E8 series Shinkansen trains on the Yamagata Shinkansen bullet train line starting August 1.
The malfunction was caused by damage to semiconductor components in the auxiliary power units, triggered by excessive current flow due to an improper combination of parts in the power supply system and high-temperature environments. This issue affected five E8 trainsets, but did not impact earlier E8 series sets (before No. 6) or the E6 series.
As a result, Tohoku Shinkansen bullet train services between Tokyo Station and Sendai Station in Miyagi Prefecture were suspended for about five and a half hours. However, no specific cause for the multiple malfunctions was mentioned in this case.
JR East has implemented countermeasures by revising the settings of the protective components in the control circuits. Following these updates, they are gradually restoring the affected E8 trainsets to operation. The normal schedule is expected to resume from August onward, though some service cancellations and reductions in additional trains will occur during August 1–8, with further timetable details to be announced later.
The trouble occurred on the Yamagata Shinkansen bullet train line between Utsunomiya and Nasushiobara stations in Tochigi Prefecture. Partly halted Yamagata Shinkansen services due to the malfunctions continued beyond the initial incident. The high current also led to heat affecting parts that shut off the current, causing them to malfunction.
It is worth noting that the resumption of operations on the Yamagata Shinkansen bullet train line will begin on August 1, but no information about the resumption of full Tohoku Shinkansen services was provided in this report.
JR East did not resume operations for all E8 series trains, only individual ones. The current status of the E8 series Shinkansen trains on the Yamagata Shinkansen line is that they are gradually being returned to service. The direct operations between Tokyo and Yamagata/Shinjō on the Yamagata Shinkansen line will resume on August 1, 2025.
In summary, JR East has identified the cause of the malfunctions and will resume operations gradually, with the first resumption scheduled for August 1, 2025. The normal schedule is expected to resume mostly from August 2025 onward, though some service disruptions may still occur during the initial phase of resumption.
- The malfunction in the E8 series Shinkansen trains was due to an issue in the photoelectric industry, as high temperatures and an improper combination of parts in the power supply system led to a surge in current, damaging semiconductor components in the auxiliary power units.
- In the finance sector, JR East has taken steps to mitigate this issue by revising the settings of protective components in the control circuits to prevent further malfunctions.
- The automotive and transportation industries could potentially learn from this incident, as the high current and subsequent heat affected parts that shut off the current, causing them to malfunction, highlighting the importance of maintaining and ensuring the quality of components in such systems.
