JVC HM-DH40000U no video output, slow response?

endcontra · #1 04-11-2015, 01:27 AM

I have a JVC HM-DH40000U DVHS deck that has gone unused for some time now, but today I attempted to start dumping some old VHS tapes for archiving. Unfortunately, it does not seem to be working. First, its slow to respond to anything: the remote doesnt work, and it takes several presses of play/stop/etc to get a response. But more importantly, I do not seem to be getting any video signal from the machine.

On my first attempt, using component output and a standard VHS tape, I did get a picture briefly; it froze and stuttered unlike typical VHS video, and the TV routinely told me that the video mode was not supported. I tried a DVHS tape via component, and got nothing at all. Ive also tried the machine on another TV, composite video, etc, no signal (not even the crappy picture I got before). Also, to clarify, no OSD information is displayed either; so it definitely seems to be a signal output issue rather than an issue with reading the tapes.

Any idea what this issue might be? Is this a known issue or something that might be a relatively easy fix?

NJRoadfan · #2 04-11-2015, 06:54 PM

So no video on the composite, S-Video, or component outputs. On a whim, if you have a computer with Firewire, will it output any video (DVHS or analog) that way or are the ports dead? Also, does the display on the front of the VCR work (S/DVHS indicators and the record/play display)?

I wouldn't be surprised if it was a problem with the power supply. It could be bad caps, or something else. I posted the service manual in this forum a while back: http://www.digitalfaq.com/forum/vcr-...anual-jvc.html

endcontra · #3 04-12-2015, 02:37 AM

Yeah, Id like to test out the firewire too, but Im fairly certain I dont have any computers with a firewire port (and even if I did, no other firewire devices, so would be difficult to verify that the firewire-enabled PC was working correctly).

The display does "work", in that its not dead; but Ive only seen it display the parentheses for the clock that isnt set, the "PM" indicator flashing randomly, and the channel number when I started pressing random buttons trying to get a response. Ive not noticed the play or stop indicators light up....only way I can tell that it is playing is listening for it.

Yeah I could potentially replace a whole component such as a power supply, but not sure how comfortable I am with replacing caps and whatnot on boards....especially when I dont even know if they are the actual problem. Will at least open it up and take a look at it tomorrow though, give it a decent dusting too.

Peter125 · #4 05-25-2015, 10:50 AM

I have exactly the same problem with my DH4K after it had been unused for a couple of years.
Did you ever get it fixed?

endcontra · #5 05-25-2015, 03:55 PM

I have not, it kinda of went on the backburner. Ive yet to test Firewire, so I have no idea if that might actually work still...kinda seems like it probably wont? I may try to find someone local that wont screw me over on a repair, because this is most likely out of my capabilities.

Peter125 · #6 05-25-2015, 04:35 PM

Thanks for your response.
I hope you can get it fixed. If not here's another option.
http://www.amazon.com/JVC-HMDH40000U.../dp/B0000ACY2B
Are they kidding?

lordsmurf · #7 06-02-2015, 01:09 PM

See if one of the places can repair it: http://www.digitalfaq.com/forum/vcr-...place-jvc.html
That's what I'd do.
I refuse to mess with changing caps or PSUs. Let the experts do it. Video is my thing, not repairing VCRs.

tvmaster · #8 09-03-2015, 12:49 PM

Quote:

Originally Posted by endcontra

I have not, it kinda of went on the backburner. Ive yet to test Firewire, so I have no idea if that might actually work still...kinda seems like it probably wont? I may try to find someone local that wont screw me over on a repair, because this is most likely out of my capabilities.

I guess this is a common occurrence with this machine: I turned mine on for the first time in three months, and all the same problems you described.
Did you ever get this sorted out? When I called JVC about another svhs machine, they gave me a number to an Atlanta repair facility (I'm in California). I can only imagine what the bill would be with shipping.

lordsmurf · #9 09-07-2015, 01:39 AM

See if TGrant can repair it.
See also: http://www.digitalfaq.com/forum/vcr-...place-jvc.html

Med1153 · #10 09-21-2018, 09:26 AM

Time has passed but did anyone ever get to the root of the issue with this? It's something that is occurring on my machine after being off for a lengthy period of time. Thanks.

hkr3 · #11 07-30-2019, 05:46 PM

I also have a JVC HM-DH40000U with the same symptoms. I can report some other information (no, I haven't solved the problem). I tried firewire, no output.

Using the Service Manual, I put the unit into Jig RCU mode (hold the Pause and Rec buttons on the unit and unplug and plug it in). From that mode, I still got no video or audio output on any of the possible outputs -- component, s-video and audio/video, as well as firewire. I did confirm that all the tape functions appear to work, it goes into play mode, pauses, stops, fast forwards, and rewind, and loads and ejects the tape.

I also tried to "pass through" the video, plugging video into the inputs both on the front and in back, and running it straight through to the output, no video display.

So, it's something blocking the display -- maybe in timer mode or the machine is sleeping?

It's definitely not capacitors in the power supply, the power supply seems to be working just fine.

endcontra · #12 11-08-2020, 05:43 PM

So lots of life changes and whatnot led to me forgetting about this other than in passing for a long time...Finally decided to address this again, Googled the issue, and thought "oh hey, heres someone with the same problem as me!"....oh, wait....

So the one thing I have tried since this original post was Firewire. I have an old Mac with a firewire port, and it worked flawlessly capturing from an old DV camera. Then I hooked up the D-VHS player to the Mac...no go of course. From what I can tell, I need to setup Firewire on the VCR to get it to work, which is impossible since I cant see the onscreen display due to no video output.
Ive also hooked it up to another TV and tried all of the connections there as well: composite, component, antenna, no go on any of them.

I feel like repair of this is going to cost me way more than I want to spend (especially with shipping there and back since I doubt Ill find anyone locally). I only have one D-VHS tape Id like to archive (everything else is standard VHS), so I really just need a well functioning VCR, although theoretically a Firewire option may give me much better captures, which is probably the main reason I havent shut the door on this option already.

latreche34 · #13 11-08-2020, 09:20 PM

This is an indication of a power section failure, Get a service manual and check all the voltages coming out the power section, also check for leaky, bulged capacitors in the power section.

tomswift · #14 05-12-2022, 12:50 PM

Actually it’s not a power failure issue. It is a failure of the entire digital board (even replacing caps doesn’t work) that handles the MPEG-2 encoding/decoding. Every thing from analog VHS & S-VHS playback/record to the D-VHS playback/record is run through the MPEG-2 board. And when that fails, the rest of the machine still works but you have no picture and sound. And the way JVC designed the deck you can’t separate the analog from the digital to turn the VCR into a S-VHS deck. And as of 2022 replacement boards are no longer available.

nihilyst82 · #15 07-02-2024, 06:51 AM

Quote:

Originally Posted by tomswift

Actually it’s not a power failure issue. It is a failure of the entire digital board (even replacing caps doesn’t work) that handles the MPEG-2 encoding/decoding. Every thing from analog VHS & S-VHS playback/record to the D-VHS playback/record is run through the MPEG-2 board. And when that fails, the rest of the machine still works but you have no picture and sound. And the way JVC designed the deck you can’t separate the analog from the digital to turn the VCR into a S-VHS deck. And as of 2022 replacement boards are no longer available.

Bumping this old thread. I am curious: What makes you so sure, that the digital board is dead? I am not saying that you are wrong, but I would not say that the power supply is ruled out as problem source. From my own knowledge (repaired broken power supply in the DH40000U before) they fail with time and use, and they like to fail partially. They provide a range of output voltages to the various sections of the VCR which may not fail completely.

The sympthoms (failing after long time storage) also points in the direction of failing electrolytic capacitors. Integrated circuits (the digital main board) ususally do not care about storage time.

I would just take the SM and check the voltages at the connectors. (But staying away from the high voltage of course).

I am bumping this old thread as I have recently COMPLETELY revived one of those decks after having recapped parts of the power supply and also have replaced ALL electrolytic caps on the PRE/REC board (the upright board in metal case next to the drum).

The unit was acutally still working in part, but signal quality was bad for analog (and HD digital Video would never decode "Error 201, calibrating ...".

Edit: Sorry, just read, that you have already tried to change caps :-). But still, recapping would always be my first try, when the deck only fails when it has been in storage for long time and behaves better when it is warmed up.

aramkolt · #16 07-02-2024, 04:47 PM

I have 3 of these VCRs that were all bought as non-working and I assumed it was a capacitor issue. Still might be, but I've fully recapped the power supplies of each, the pre-rec board, and all of the SMT caps in the digital board and all three still have no video output. I also recapped the area with the voltage regulators off to the front left. The voltage regulator caps had gone open on at least 2 of the 3 as this is a high-heat area per indications of heat on the main board.

I haven't tried to access the MPEG2 stream over firewire on them, but I presume it won't work. My understanding is that regular firewire capture programs (looking for a DV stream) would not work with the DH40K anyway since it's an MPEG2 stream, not DV.

HDVsplit, however, can capture MPEG2 streams I believe, so if you were to try to capture it with anything, that'd be what you'd want to try.

Soooo if I actually had a working DH40K, I could swap out the digital board and it would be pretty easy to prove that the issue lies there by swapping the good digital board into one of my bad VCRs.

Doing all of that recapping, particularly to the digital board that uses a bunch of SMTs was pretty time consuming, so I'd love to find out if the issue is there for sure and if whatever has failed is actually on that board or if the issue is elsewhere...

I suspect that the one instance of someone improving a poor picture with recapping is probably not the same issue as others are getting with no video output at all unfortunately.

2 of my 3 units also have the slow responsiveness as well and will actually play the tape as though it is working sometimes, but there's still no picture output. At first I actually thought the slow button press responses was due to the switches being oxidized, so I replaced all of those as well on a couple of units without any difference in the end.

Would love to hear any other success stories about a DH40K that had no video output that was somehow brought back and what the issue ultimately was caused by....