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-   -   JVC HR-S9500U VCR flashing AUTO? (https://www.digitalfaq.com/forum/vcr-repair/12007-jvc-s9500u-vcr.html)

SeeNoEvil 07-08-2021 04:57 PM

JVC HR-S9500U VCR flashing AUTO?
 
I have a JVC HR-S9500U NTSC VCR, which was working fine this evening playing a tape. I stopped the tape, rewound it a bit, then pressed play and the machine shut down flashing AUTO on the LCD. Never done this before and I've had it for about 3 years. It doesn't get a huge amount of use, maybe once every few months for a transfer project. I'm in the UK running it at 110v though a Goldsource ST-1500 power converter, which has worked fine for the last 3 years, so if that was the issue I would assume that it would have gone wrong pretty quickly.

I can turn it back on from the unit or remote and the blue screen pops up, but disappears after 3 seconds and back to AUTO flashing. I can put a tape in and eject it. Looking inside the tape seems to travel as it should and reels out around the drum (which is spinning), but as so as that happens the machine shuts down and flashes AUTO again. I have tried a few things;

Switching the machine off / or leaving it unplugged - no difference.

Holding the power button down on the unit and remote for 10 seconds (actually I've tried virtually every button) - no difference

Trying to navigate the menu settings in the three seconds before it shuts down - no difference

Inserting different tapes, including one with the recording tap intact - no difference

I have seen a post online that this may be the auto setup mode and it needs to scan the TV stations to set itself up, but living in the UK I have nothing I can connect it to, to try that.

Looking inside there is nothing obviously wrong/loose/broken. Looking around online there seems to be a number of different suggestions people are making. The last time I had it repaired was about £200 with the engineer call out charge, which was still cheaper than anything I could buy on eBay at the time, but this is now the second time it's playing up since I got it 3 years ago.

I've had a PAL HR-S7600 since around 2005, that one's a real workhorse and has never gone wrong and it only cost me £40 from a guy selling piles of them out of a shed! Living in the UK, the decent transfer NTSC VCRs are both vastly expensive to buy, and difficult and expensive to repair too.

latreche34 07-08-2021 08:06 PM

Does it do it even with no tape inside the deck? If so it is most likely a blown protection fuse, JVC used protection fuses on every stage of the VCR, They look like tiny transistors but with only two soldered legs, Unfortunately you will have to figure out what is not powering up that causes the system control to default to such state, One of the ways is to probe all those fused links, if you get power on one side of them and no power on the other side then you know it's blown.

These are silly suggestions:
- There is a battery cell at the back of the VCR, try replacing it with a fresh one, this is less likely to cause this problem but it is good to have it replaced to keep your setting saved.

-Make sure the unit is not programmed to record automatically.

SeeNoEvil 07-09-2021 10:57 AM

Quote:

Originally Posted by latreche34 (Post 78534)
Does it do it even with no tape inside the deck?

Yes, it's the same either way. I can use the power button to turn the machine on, and the LCD changes to its normal display, but after 3 seconds it switches off and goes back to AUTO. Tape or not.

Quote:

Originally Posted by latreche34 (Post 78534)
Make sure the unit is not programmed to record automatically.

I saw someone had suggested this to someone else with a similar issue, so I put a recordable tape in, but it made no difference. I also left it for a while to see if would resolve itself. After 30 mins or so, the LCD display powered down and dimmed to --:--:--, but once powered back up it went back to AUTO

I'll open it up and have a look, any idea what the protection fuses look like?

latreche34 07-10-2021 12:36 AM

Get the service manual for your model and look for components with ID name CP followed by a 3 or 4 digit number, CP stands for circuit protection, Find their number and look in your VCR to locate them and test them.

SeeNoEvil 07-12-2021 12:22 PM

5 Attachment(s)
I emailed the guy who (expensively) fixed my VCR two years back, a new pinch roller as I remember. Anyway after explaining what I had above he replied with the following;

Quote:

The most likely cause is two small gears under the head drum which have cracked and stopped the drum moving in order to track correctly. These gears are not available from JVC and nor is the head drum itself. I'm sorry to say you will have to purchase another machine.
I searched this forum and found someone else had posted about this issue being the cause of their AUTO-off as well, so I dismantled the drum assembly (assuming I couldn't make it too much more broken), and from the photos you can see both the top and separate bottom plastic gear piece on one side had cracked though completely, more than enough to bind the gears when rotated, and the gear on the other side had the beginnings of a crack as well.

I hooked up a variable DC PSU to the motor just to check it was actually working, and it was rotating the bottom assembly of gears both ways fine, but then of course binding & drawing a lot more amperage once the drum was assembled back together.

NJRoadfan 07-12-2021 01:42 PM

The AUTO display is actually the onboard clock scanning TV stations to automatically set the VCR's onboard clock. Ignore it as a symptom of the problem.

latreche34 07-12-2021 03:42 PM

Quote:

Originally Posted by SeeNoEvil (Post 78575)
I emailed the guy who (expensively) fixed my VCR two years back, a new pinch roller as I remember. Anyway after explaining what I had above he replied with the following;



I searched this forum and found someone else had posted about this issue being the cause of their AUTO-off as well, so I dismantled the drum assembly (assuming I couldn't make it too much more broken), and from the photos you can see both the top and separate bottom plastic gear piece on one side had cracked though completely, more than enough to bind the gears when rotated, and the gear on the other side had the beginnings of a crack as well.

I'me aware of that problem, I even wrote a precedure to disable the DD system here, But the shuttdown from that problem is different, it will not display Auto, it just shutts down completly that's why I didn't think it is, or at least not the main reason.

SeeNoEvil 07-12-2021 04:37 PM

Quote:

Originally Posted by latreche34 (Post 78577)
I'me aware of that problem, I even wrote a precedure to disable the DD system here, But the shuttdown from that problem is different, it will not display Auto, it just shutts down completly that's why I didn't think it is, or at least not the main reason.

I did actually try that when I was fiddling around with it earlier, before I saw your post. I took out the two split gears which would tilt the head and reassembled it just as a test, but it made no difference to the AUTO shutoff.

I don't really have the electronic knowledge or expertise to follow circuit diagrams and test components on the circuit board, without it being explained really simply.

All this aside, this is the second time this machine has gone wrong in 3 years. Actually the third as it also once ejected a tape without reeling it back in, so I had to remove the cover and free the tape off to get it out. I've had a PAL 7600 for around 16 years which has never had any problems, so I'm thinking I might do better upgrading to the 9600 or 9800 anyway.

latreche34 07-12-2021 05:47 PM

Quote:

Originally Posted by SeeNoEvil (Post 78578)
I did actually try that when I was fiddling around with it earlier, before I saw your post. I took out the two split gears which would tilt the head and reassembled it just as a test, but it made no difference to the AUTO shutoff.

So there you have it, DD system could still be a problem but not the one causing the AUTO display problem just like I thought.

SeeNoEvil 08-02-2021 03:14 AM

Huge thanks to a user who gave me detailed instructions via PM, I checked the two CPs that were easily visible (CP5301 & CP4001) using a voltage tester screwdriver, and they both had power on both sides, so I removed the tape transport, and found two more (CP5302 & CP3001) which also both tested fine. Looking at the manual there are 7 CPs. Hunting on both sides of the circuit board I found CP3003 was a white block into which two contacts from the tape transport plug into, but couldn't find CP3002 or CP5303. Just in case, I tested the same with my multimeter in continuity mode and they all checked out okay the same. I re-assembled it all fine but it still comes up with the same error. I've already decided to replace this VCR with a JVC HR-S7900U, so it's somewhat academic now.

As an aside back to the cracked black gears under the dynamic drum problem, I checked with a friend who does a lot of fine 3D printing with the latest equipment, and he said that while he could perfectly replicate any of the gears, the limitations of 3D printing mean this would be a poor option. Not only are 3D prints not really strong enough, they can also warp easily where there is heat, and being such fine gears, it wouldn't take much damage or warping to cause the mechanism to bind.

I'm a special effects mould-maker by trade, but I've never tried to replicate such a fine items as these gears. I'm sure there are very strong resins out there perfectly suited to this sort of application, so that is an option.

Has anyone else tried anything like this? Or are there off-the-shelf gears you can buy which would make a suitable replacement?


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