In the last couple of months anything I record on to the hard drive is dreadful quality and you have to have the volume right up to hear anything and what you can hear is bad quality. Things I have recorded a long while ago play back fine.
Can't see any reason why a retune would affect the existing recordings. Fruitbat simply wants to determine if the stations are correctly tuned in and if not then that might be the reason for poor recording. The fact that old programs play OK narrows it down to the recording quality which is dependent on the DVD recorder or/and the quality of the signal being received. Maybe your aerial needs looking at as this could cause severe degradation of the incoming signal.
Try taking out all leads and cleaning the connections. Unless they are the gold plated type there is always a danger that they have oxydised and that will give bad connections that can result in the problems that you are experiencing.
Hardly likely as everything is playing from old recordings and it is only new recordings that are being affected that is unless I have made an incorrect assumption ie that the Hard Drive Recorder includes its own tuner and thus does not depend on connections from the TV. Unfortunately the OP does not state what model it is so maybe a confirmation one way or the other would help to narrow down the problem source.
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