JVC HM-DR10000 bad play of analog SP mode?

[promoter_2000]

Hello everyone. My D-VHS JVC HR-DM10000 has a strange problem: it perfectly reads tapes recorded in analogue LP (VHS and S-VHS) and in digital (STD and LS3) but very badly the analog VHS and S-VHS tapes recorded at SP speed (standard play). In SP the image jumps vertically and suffers from video noise (sandy images); if I insert the DIGITAL TBC / DNR the image stops jumping but continues to vibrate vertically and the video noise remains. The even stranger thing is that activating the slow motion (still / frame by frame / cue forward or back) the image is perfect again even in SP until I go into normal play: at that point the image remains stable and clean for exactly two seconds and then back to vibrate (if TBC on) or to jump (if TBC off) with the usual video noise. I tried to remove the B.E.S.T. and to adjust the tracking manually but the image gets even worse. I opened the chassis and found in the power supply 4 broken capacitors: I changed them with new capacitors but without solving anything. I also tried to change the digital card that is on the bottom of the device (but always without success). The left and right guide rollers run all the way down without apparent problems (I also cleaned the plastic rails with isopropyl alcohol and then lubricated with molikote) but I do not think they can be the culprits if the LP and in digital SP / LP everything works perfectly . At this point I'm thinking that the problem is some damn condenser somewhere but I do not know where. I'm doing it wrong? Please, would anyone have any idea what this failure could do and how could I solve it? Thank you all.

From my previous post to today I tried to ask an old repairer of VHS video recorders (the only one still active in my area) which was, according to him, the reason for the problem and he replied that it could be the video heads consumed. Could it really be this? But if they were the video heads ruined, because the return from the frame by frame for two seconds (ie before appearing the symbol of the play overlay) the image is absolutely perfect even the SP? Please, could someone help me to understand?

[lordsmurf]

The SP heads are damaged.

It sounds like the deck has multiple problems. I've never liked the built quality of JVC D-VHS decks.

If it's bad condenser, just a get a new R2 unit.

[promoter_2000]

Ok, it seems to be the fault of the SP heads (I have always thought, wrongly, that the video heads were always the same for SP and LP). From the service manual it seems that it is sufficient to unscrew 3 screws and detach two flat cables to remove the entire head block. Is it really so or even this time wrong?

[promoter_2000]

In fact it is just like that: just unscrew the three screws at the base of the support, remove the two flat cables and the head block can be easily removed. Lordsmurf is right: by examining with a magnifying glass the upper drum, which contains six heads arranged diametrically between them in two groups of three, the central head of one of the two groups (I assume the one assigned to the standard play) has the left side of the visibly broken / worn air gap.