What causes tracking problem on every JVC?
 

Has anyone run into this problem with JVC VCRs where, eventually, when you start a tape from the beginning at EP speed, the tracking will start rolling and the sound will go down? I've had more than one JVC start behaving like this eventually. Note the specific conditions: it only does it at EP speed and only within the first half-hour or so of tape length. Almost EVERY JVC I've had has eventually gone bad like this and I'm tired of it.

What causes this and is there a fix for it?

Multiple reasons, Dirty sync pulse head, miss aligned sync pulse head, Tape tension problems, These VCR's are over 3 decades old and they need servicing.

Which exact models?

I have 3 jvc's, best i have that play Ep's tapes is the SR-TS1U (ntsc), and on the hr-s8600ms i had to adjust the P2- P3 guides for a very decent playback (audio and video). Food for thought

Try to play with the modes to begin with BEST mode on/off : norm or edit (forget the other modes)

Two DH-30000Us and one HRS7800U have now done it.