No sooner than the debacle had occurred of Thameslink’s trains stalling and refusing to reboot until specialists were brought in to sort them out – the whole hog is re-enacted once again as if the first time simply wasn’t enough! Once again trains had to be rebooted by specialists! Thameslink asserted it was a ‘small number of trains affected.’ However it seems rather more than a small number were affected. Trains were stuck as far south as Haywards Heath and as far north as St. Albans. One person described it as ‘all Thameslink services totally borked.’
Power was restored at 18.45pm, and that is when the problems started. Clearly the trains had enacted the same scenario as on 9th August 2019 – that is they refused to restart after a power cut. It was a report by the Standard that confirmed the stranded trains needed rebooting.

Tweet from BTP KIngs Cross. Source: Twitter. (Tweet now deleted however a screengrab has been used.)

Told to get the bus. Except the bus service had finished at the time! Source: Twitter. (Tweet deleted but a screengab has been used.)

My dad is stuck in a tunnel… Source: Twitter. (Tweet has been deleted thus a screengrab has been used.

Note: The above tweet was deleted by its user thus a screencap has been used here.

Stricken train inside the tunnel just before St. Pancras Thameslink. Source: Twitter.

Stuck in the tunnels two hours and yet so close to the platforms! Source: Twitter. (Tweet has been deleted thus a screengrab is used)
From being stuck underground in a train between Kings Cross and Kentish Town for 1.5 hours with no phone signal to being evacuated and escorted back to Kings Cross station. I couldn’t have asked for a better start to the bank holiday weekend. Thank you @TLRailUK #Thameslink pic.twitter.com/I3SK3s5OxD— lockworm (@lockworm) August 23, 2019

Evacuation from a train just outside St. Pancras Thameslink. Source: Twitter

Note: The above tweet was deleted by its user thus a screencap has been used here.

Note: The above tweet was deleted thus a screencap has been used here.

The user’s account has been deleted however a screencap of the tweet is used here.

Clearly, trains still being cancelled four hours after the outage. Source: Twitter.
When’s the next train?#Thameslink person 1: “Could be two hours”
— John Fleming (@thejohnfleming) August 23, 2019
Thameslink person 2: “Could be a few minutes”
Thameslink person 3: “There are no trains”
Service as normal on Thameslink pic.twitter.com/aXHLWlGy6L

Just another Friday on the Bedpan Source: Twitter. (Note tweet has been deleted thus a screengrab is used.)
@TLRailUK what are you doing at West Hampstead Thameslink? Just running empty trains through the station for a laugh?
— Jack Douglas (@JackADouglas) August 23, 2019
Sorry Lauren, there have been a number of trains which required evacuation and unfortunately there was not enough personnel for those to be done all at once. We entirely appreciate how distressful the wait must have been and can only apologise ^Lola
— Thameslink (@TLRailUK) August 23, 2019
Thameslink your service is an absolute disgrace. It’s the third time in a month I have been stranded in London with no replacement buses or other means to get home. Are you going to pay for my cab fares that I have incurred to get from London to Luton?
— BK (@BK28052930) August 23, 2019
Hi there, these services have regretfully been affected by damage to the overhead wires between St Albans and London Blackfriars . Sincere apologies for any inconvenience caused. ^Lola
— Thameslink (@TLRailUK) August 23, 2019