No sound on certain files

on my Vero 1 that has been moved to an older TV I now miss sound on some files.

Anything fishy with the mediainfo?

General
Unique ID                                : 298525076609027358790796944597821887836 (0xE095D6A2A3B6C3AE39A24DA0702F155C)
Complete name                            : s02e05.mkv
Format                                   : Matroska
Format version                           : Version 2
File size                                : 477 MiB
Duration                                 : 23mn 12s
Overall bit rate                         : 2 875 Kbps
Encoded date                             : UTC 2016-03-19T11:29:10Z
Writing application                      : HandBrake 0.10.5 2016021100
Writing library                          : Lavf55.12.0

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : High@L4.1
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 4 frames
Codec ID                                 : V_MPEG4/ISO/AVC
Duration                                 : 23mn 12s
Bit rate                                 : 2 434 Kbps
Width                                    : 702 pixels
Height                                   : 576 pixels
Display aspect ratio                     : 4:3
Original display aspect ratio            : 4:3
Frame rate mode                          : Constant
Frame rate                               : 25.000 fps
Color space                              : YUV
Chroma subsampling                       : 4:2:0
Bit depth                                : 8 bits
Scan type                                : Progressive
Bits/(Pixel*Frame)                       : 0.241
Stream size                              : 404 MiB (85%)
Writing library                          : x264 core 142 r2479 dd79a61
Encoding settings                        : cabac=1 / ref=3 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=7 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=18 / lookahead_threads=3 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=40 / rc=crf / mbtree=1 / crf=18.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / vbv_maxrate=62500 / vbv_bufsize=78125 / crf_max=0.0 / nal_hrd=none / filler=0 / ip_ratio=1.40 / aq=1:1.00
Default                                  : Yes
Forced                                   : No
Color primaries                          : BT.601 PAL
Transfer characteristics                 : BT.709
Matrix coefficients                      : BT.601

Audio #1
ID                                       : 2
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Mode extension                           : CM (complete main)
Format settings, Endianness              : Big
Codec ID                                 : A_AC3
Duration                                 : 23mn 12s
Bit rate mode                            : Constant
Bit rate                                 : 192 Kbps
Channel(s)                               : 1 channel
Channel positions                        : Front: C
Sampling rate                            : 48.0 KHz
Bit depth                                : 16 bits
Compression mode                         : Lossy
Stream size                              : 31.9 MiB (7%)
Title                                    : Mono
Language                                 : Swedish
Default                                  : Yes
Forced                                   : No

Audio #2
ID                                       : 3
Format                                   : AC-3
Format/Info                              : Audio Coding 3
Mode extension                           : CM (complete main)
Format settings, Endianness              : Big
Codec ID                                 : A_AC3
Duration                                 : 23mn 12s
Bit rate mode                            : Constant
Bit rate                                 : 192 Kbps
Channel(s)                               : 1 channel
Channel positions                        : Front: C
Sampling rate                            : 48.0 KHz
Bit depth                                : 16 bits
Compression mode                         : Lossy
Stream size                              : 31.9 MiB (7%)
Title                                    : Mono
Language                                 : English
Default                                  : No
Forced                                   : No

Text
ID                                       : 4
Format                                   : VobSub
Codec ID                                 : S_VOBSUB
Codec ID/Info                            : The same subtitle format used on DVDs
Language                                 : English
Default                                  : No
Forced                                   : No

Menu
00:00:00.000                             : :Chapter 1
00:01:03.440                             : :Chapter 2
00:03:14.000                             : :Chapter 3
00:12:16.400                             : :Chapter 4
00:22:39.600                             : :Chapter 5

1 channel AC3 looks weird to me.

If your TV doesn’t support AC3 in, then you should disable passthrough.