[Solved] MythTV Light 31 on RPi4 - recording fails as can't get lock

Have a MythTV related problem? Ask for help from other MythTV users here.

Moderator: Forum Moderators

Post Reply
AustinS68
Newcomer
Posts: 8
Joined: Fri Jul 30, 2021 3:47 pm
Great Britain

[Solved] MythTV Light 31 on RPi4 - recording fails as can't get lock

Post by AustinS68 »

Dear all,

I've been using MythTV for >10 years and always managed to find my way round problems, but this one is stumping me. I've read back through the troubleshooting forum and I can't find anyone else with this problem.

I'm using a brand new RPi4 with SSD, running up-to-date RaspPi OS Buster with MythTV Light 31, using a PCTV 292e DVB-T2 tuner. Database was imported from old 0.28 system (running on an Intel NUC using Ubuntu 16.04.7 LTS) and migrated to the new schema, and channel scan succeeded.

Backend and frontend run fine (no audio on playback, but I am sure I can figure that out). I just can't record, because I never get a signal lock.

I can scan and zap using dvbv5-tools on the Pi using this tuner, and dvb-fe-tool verifies a lock. It doesn't show a lock when using MythTV to attempt recording. The same tuner works fine connected to the old backend, so it's not the tuner or my signal.

I've captured a mythbackend log file, running with "-v all", but I don't seem to be able to attach it or include a link to it.

Thanks in advance for any pointers.

Best regards,
Austin.
Last edited by AustinS68 on Sat Aug 07, 2021 5:44 pm, edited 1 time in total.
User avatar
kmdewaal
Developer
Posts: 640
Joined: Wed Dec 07, 2016 8:01 pm
Netherlands

Re: MythTV Light 31 on RPi4 - recording fails as can't get lock

Post by kmdewaal »

It is good to know that your hardware is working OK. When you can do a channel scan with mythtv-setup then also mythbackend should work.
What could be an issue is the upgrade of the database from v28 to v31. There have been quite a lot of changes for DVB in v31 and it could just be that the database upgrade has left the tuner configuration in an undefined state.
I suggest that you delete the capture card and the video source, create them again and do a new channel scan, as described in the Wiki https://www.mythtv.org/wiki/Channel_Scanning.

About attaching files to this forum, you will be able to do that after a while but only for small files and the mythtv logs are usually not small.
I suggest using a file sharing service and post the link here.

Hope this helps,
Klaas.
AustinS68
Newcomer
Posts: 8
Joined: Fri Jul 30, 2021 3:47 pm
Great Britain

[Solved] Re: MythTV Light 31 on RPi4 - recording fails as can't get lock

Post by AustinS68 »

Klaas, thanks, that solved it. By looking at the database, it seems that the mod_sys field was wrongly set in the dtv_multiplex table.

Best regards,
Austin.
Post Reply