JVC DR-MV1S REPAIR/LS1 PROCESSOR FIASCO QUESTIONS

[ggoat!!!]

Forgive me if I'm not supposed to do this, but I'm not sure where I'm suposed to post this information; please ignore my other posting of this information as it is under a different model number heading.

Hello everyone...

I know this is a long old topic, but the machines I am going to refer to have just started to exhibit the dreaded "loading" and screen-jizz problems. They both acted up in the same week, with similar results. I purchased two of the DR-MV1S units back at the end of 2004 for my parents; long-time videophiles. My mother recently had a stroke, and wanted my dad to make some home movie dvd's for her to watch. Therein came the current situation.

I have been aware of the "loading" problem for some time, but these machines just for some reason never really had the problem for any length of time; they always fixed themselves without having to do anything to them and always worked when you needed them. Well, now it seems they have both bit the dust.

I read thoroughly all the posts here, and performed the necessary repairs on the first of the two units; upgraded the resistors to 560ohm 2watters (they fit fine), the capacitors to 16v 2200mfd (all I could get locally) and installed the two 1k resistors. This first unit I attempted to repair was the one that showed the LEAST problem before-hand. It just locked up with the "loading" message, but never had the green line display problem. Well, once I put it back together, the loading problem was fixed, but the video output was now merely a black screen with occasional whitish noise spots appearing. Nothing else. Remember, this deck's picture output was fine before it locked up the other day (one of the rare times it developed the "loading" lock up). So, I figured maybe I'd damaged the processor board somehow when I installed the 1k resistors. So...

Being very discouraged, at this point I turned my attention to the 2nd unit, much less used but much more frequently exhibiting the "loading" problem recently. Also, this 2nd unit recently actually HAD the green line/screen display problem. Basically, the 2nd unit was stuck in loading lock-up mode with the green lines. So, rather than repair at this time the capacitors/resistors as I did in the 1st unit, I first decided to see if I really did damage the processor board in the 1st unit by swapping out the processor assembly from the 2nd unit into the 1st unit (with the repaired capacitors/resistors) since the "loading" problem in the 1st unit seemed to have been fixed. BUT...when I installed the processor from the 2nd "less working" locked up DR-MV1S (that I hadn't repaired anything in at this point) in the 1st DR-MV1S that I had just "repaired" (loading problem fixed), the previously repaired "LOADING" message appeared in the 1st unit with the subsequent locking up. Since I had just replaced/repaired the components in this 1st unit and the loading problem disappeared, I'm assuming the processor is fried in the 2nd unit, which is why this processor out of the 2nd unit causes the previously repaired 1st unit to suddenly go back into the "loading" lockup. When I put back the processor from the 1st unit (the one I think I might have damaged) back into this 1st unit, the loading problem disappeared but the screen still remains black with occasional white/noise.

****I'm just reading this over, and it seems a little confusing. Here is a quick sum-up:

1) 1st unit..."loading" locked up, but no previous green lines in screen
2) 2nd unit..."loading" locked up, much more frequent, green lines in screen
3) Repaired capacitors/resistors in 1st unit; loading problem disappeared, but screen now black with occasional white noise
4) Swapped out processor board from untouched 2nd unit into 1st unit; loading lock up problem returned to 1st unit
5) Swapped processor boards back to original state; 1st unit loading problem disappears again, screen remains black with white noise randomly
6) Nothing ever repaired or altered in 2nd unit


So, what I'm wondering is WHAT DO I DO??? I spent over $700 for both of these back then as gifts for my parents. My dad loves using them; he copies home movies all the time. Also, what kills me is the quality of the discs these units make. Sure, they are complicated to work, but they make great copies and clean up signals nicely. I know of NO OTHER current combos with the LS1 chipset, FR recording, and the picture quality of this JVC. The newest version (DR-MV7S) I don't think does the FR mode, which is what my dad uses exclusively. LG has the LS1 chips, but no FR mode.

Are these units worth repairing? To repair them at this point, I think they need entire new processor boards each. Does anyone have any ideas about what else these problems could be? I haven't altered anything in the 2nd unit; the 1st unit again has had at least the capacitors and the resistors repairied properly (except for possibly the resistors on the processor board). Am I correct in my assumption of the death of the processor in my 2nd unit as described above?

If I DO need new processor boards, what would be the likelihood that this will fix these units? What else could go wrong? Are the NEW processor boards that you can buy as parts UPDATED so that you don't have to add the resistors? JVC doesn't seem to be able to tell me. I would never buy the boards and then have to solder resistors to them.

So....PLEASE anyone, help any way you can. Does anyone know where I can get new processor boards CHEAP? The JVC site lists them as nearly $300; they are nearly double that almost everywhere else. I'm not spending that much to fix these. BTW...I purchased these units back then from a reseller, and although brand new/unused, the serial numbers are gone. So, I doubt JVC will fix these for free. I do have receipts somewhere though.


Looking forward to anyone's help!



Thank you VERY much!
Jeff

[InXess]

Find the nearest JVC repair shop, speak with the repair guy directly, offer him a beer and go from there... If you have no knowledge about the equipment you try to fix at least get the service manual and have someone knowledgeable assist you with the repair. Otherwise you may get stuck just like you have...

[ggoat!!!]

Hi there...thanks for the response.

I didn't want to give the impression that I'm not knowledgable about the repair; I've been repairing electronics for 20+ years. Also, after reading 16 pages of posts from experienced repairmen/enthusiasts, I figured they had a pretty good grasp of what needed to be done to repair this problem. Regarding the processor board failure in the first unit, I merely entertained the idea that I may have possibly caused a malfunction in the 1st unit's processor board but I don't really think this is the case. Just the idea of the difficulty of soldering those two 1k resistors to such tiny robot-made pin-tip size areas greatly enhances the possibility of error. I wanted to point that out in my post. Regarding being "stuck", it should also be noted that I haven't attempted to repair the 2nd unit. I merely swapped the processor board out of that unit to test it in the known working (loading problem-free) 1st unit, which is what made me determine that the processor in the 2nd unit had previously fried before I ever opened it up when merely installing this processor board in the 1st unit caused the loading problem to instantly reappear.

Regarding the processor boards, do they come with the "can"? And, are the replacement parts revised so that they won't fry again?

[mgy999a]

It does sound like both processor units are fried.

I have a similar problem with my JVC DR-M10. A couple of months ago, it developed the dreaded LOADING problem. I found and replaced a bad capacitor and then the recorder worked fine – for a few weeks. Now, it only works for a couple of hours then locks-up. No LOADING message but it loses video (black screen/white sparkles, same as you have), loses audio, stops writing to disc, and it ignores all front panel & remote controls. I have to unplug, wait a few minutes and then plug it back in. It’s not a heating problem and it is not related to the power supply. I suspect but can not prove that it is the processor.

Don’t waste your money on a service manual. I bought one but compared to the SAMS service manuals of years ago, the JVC service manual (at least the one that is available to the general public) is pretty limited. It did help me with my power supply problem but that’s about all it is good for. There are no timing diagrams or other info that would let you troubleshoot the processor unit.

I have googled the net looking for a replacement processor but didn’t find a thing. And the JVC website was no help at all.

Yes, the processor comes in the "can". The can is part of the heat sink for the processor chip itself. There is a small thermal transfer pad between the chip and the can, similar to the thermal pads used for Pentium and AMD processor chips in a PC. I don't recommend removing the processor board from the can. There is really nothing to see on that side of the board anyway. Just more of the same surface mount components.

As for your second question, I don't know if JVC ever upgraded the processor unit to prevent being fried. I suspect that the failure of the processor is a by-product of the power supply problems. As long as the power supply is working, the processor is probably not at risk. Of course, that is only my opinion.

A JVC service center might be your only option for parts and/or repairs.

Replacement dvd recorders of equal capability seem to be hard to find. JVC isn’t making one right now unless you want to consider spending $1300 for their DR-DX5S. I have heard good things about the Pioneer DVR-640H and the Toshiba RD-XS35 but neither one has the LSI DiMeNsion chipset that does such a good job converting VHS to DVD. Of the current recorders that do contain that chipset (such as the LG DR1F9H), the user reviews have not been very favorable.

I know that this has not been very helpful but it might save you some time in your search for a solution.

[lordsmurf]

2010 update -- Fixing the JVC DVD Recorder "LOADING" Issue / JVC Will Not Recognize Blank DVDs
I've compiled a new thread on this topic at http://www.digitalfaq.com/forum/showthread.php/fixing-jvc-dvd-2008.html -- I've been trying to organized all available JVC information better for those who need it!


************************************************** **********************

This may seem Mickey Mouse, but did you ever consider the media or dirty power? Maybe even a weak video input signal? Remember that "loading" is a generic message, it may as well say "ERROR" instead.

What discs are you using?
Does it have any kind of surge protector or UPS, maybe even AVR?
How is the video signal quality into a VCR or tv alone?

First generation machines had this issue on a small portion of machines, but JVC has always fixed them. I would suggest that route.

[InXess]

Hi there...thanks for the response.

I didn't want to give the impression that I'm not knowledgeable about the repair; I've been repairing electronics for 20+ years. Also, after reading 16 pages of posts from experienced repairmen/enthusiasts, I figured they had a pretty good grasp of what needed to be done to repair this problem.
...

Sorry then... Too many users attempt to do what they're not supposed to do without a proper research. Can't say if your boards/CPU's are OK or not but I have one remark.
I recall reading that after component swap for some recorders units refused to operate since the ID of this component was logged by the unit. Switching back to the working one did not help as the unrecognized module was logged and units won't work until the ID is reentered or memory purged. Don't know how it works in JVC's example but you may have to speak with someone about this possibility.
Btw. the thought about the beer with a repair guy wasn't a joke...

[jethro12]

Forgive me if I'm not supposed to do this, but I'm not sure where I'm suposed to post this information; please ignore my other posting of this information as it is under a different model number heading.

Hello everyone...

I know this is a long old topic, but the machines I am going to refer to have just started to exhibit the dreaded "loading" and screen-jizz problems. They both acted up in the same week, with similar results. I purchased two of the DR-MV1S units back at the end of 2004 for my parents; long-time videophiles. My mother recently had a stroke, and wanted my dad to make some home movie dvd's for her to watch. Therein came the current situation.

I have been aware of the "loading" problem for some time, but these machines just for some reason never really had the problem for any length of time; they always fixed themselves without having to do anything to them and always worked when you needed them. Well, now it seems they have both bit the dust.

I read thoroughly all the posts here, and performed the necessary repairs on the first of the two units; upgraded the resistors to 560ohm 2watters (they fit fine), the capacitors to 16v 2200mfd (all I could get locally) and installed the two 1k resistors. This first unit I attempted to repair was the one that showed the LEAST problem before-hand. It just locked up with the "loading" message, but never had the green line display problem. Well, once I put it back together, the loading problem was fixed, but the video output was now merely a black screen with occasional whitish noise spots appearing. Nothing else. Remember, this deck's picture output was fine before it locked up the other day (one of the rare times it developed the "loading" lock up). So, I figured maybe I'd damaged the processor board somehow when I installed the 1k resistors. So...

Being very discouraged, at this point I turned my attention to the 2nd unit, much less used but much more frequently exhibiting the "loading" problem recently. Also, this 2nd unit recently actually HAD the green line/screen display problem. Basically, the 2nd unit was stuck in loading lock-up mode with the green lines. So, rather than repair at this time the capacitors/resistors as I did in the 1st unit, I first decided to see if I really did damage the processor board in the 1st unit by swapping out the processor assembly from the 2nd unit into the 1st unit (with the repaired capacitors/resistors) since the "loading" problem in the 1st unit seemed to have been fixed. BUT...when I installed the processor from the 2nd "less working" locked up DR-MV1S (that I hadn't repaired anything in at this point) in the 1st DR-MV1S that I had just "repaired" (loading problem fixed), the previously repaired "LOADING" message appeared in the 1st unit with the subsequent locking up. Since I had just replaced/repaired the components in this 1st unit and the loading problem disappeared, I'm assuming the processor is fried in the 2nd unit, which is why this processor out of the 2nd unit causes the previously repaired 1st unit to suddenly go back into the "loading" lockup. When I put back the processor from the 1st unit (the one I think I might have damaged) back into this 1st unit, the loading problem disappeared but the screen still remains black with occasional white/noise.

****I'm just reading this over, and it seems a little confusing. Here is a quick sum-up:

1) 1st unit..."loading" locked up, but no previous green lines in screen
2) 2nd unit..."loading" locked up, much more frequent, green lines in screen
3) Repaired capacitors/resistors in 1st unit; loading problem disappeared, but screen now black with occasional white noise
4) Swapped out processor board from untouched 2nd unit into 1st unit; loading lock up problem returned to 1st unit
5) Swapped processor boards back to original state; 1st unit loading problem disappears again, screen remains black with white noise randomly
6) Nothing ever repaired or altered in 2nd unit


So, what I'm wondering is WHAT DO I DO??? I spent over $700 for both of these back then as gifts for my parents. My dad loves using them; he copies home movies all the time. Also, what kills me is the quality of the discs these units make. Sure, they are complicated to work, but they make great copies and clean up signals nicely. I know of NO OTHER current combos with the LS1 chipset, FR recording, and the picture quality of this JVC. The newest version (DR-MV7S) I don't think does the FR mode, which is what my dad uses exclusively. LG has the LS1 chips, but no FR mode.

Are these units worth repairing? To repair them at this point, I think they need entire new processor boards each. Does anyone have any ideas about what else these problems could be? I haven't altered anything in the 2nd unit; the 1st unit again has had at least the capacitors and the resistors repairied properly (except for possibly the resistors on the processor board). Am I correct in my assumption of the death of the processor in my 2nd unit as described above?

If I DO need new processor boards, what would be the likelihood that this will fix these units? What else could go wrong? Are the NEW processor boards that you can buy as parts UPDATED so that you don't have to add the resistors? JVC doesn't seem to be able to tell me. I would never buy the boards and then have to solder resistors to them.

So....PLEASE anyone, help any way you can. Does anyone know where I can get new processor boards CHEAP? The JVC site lists them as nearly $300; they are nearly double that almost everywhere else. I'm not spending that much to fix these. BTW...I purchased these units back then from a reseller, and although brand new/unused, the serial numbers are gone. So, I doubt JVC will fix these for free. I do have receipts somewhere though.


Looking forward to anyone's help!



Thank you VERY much!
Jeff

Did you try removing the 2 1k resistors from the digital board to
see if it rectifies the problem with the video. When I first installed
the 1k resistors to my first unit I removed a resistor in the process
and didn't realize it and got no response from the unit .Make sure to get
a good magnifier to make sure you have no solder bridges around
and you made the right connections. I have upgraded two
units andhave had no problems with them other than the vcr sections in which I
have some intermittent noise and occassionally they won't come online
during a powerup and don't respond to any controls but have found a few work arounds
on that problem. I would say try to get them fixed by JVC but you have already
done work on them which they will be able to tell.
Another thing is to always keep them in power save mode otherwise
they could suffer heat damage to the digital board or the
power supply .I rigged mine so that the fan comes on when
it is standby and out of power save mode to keep the digital
board from getting damaged.
One thing you can do is look on Ebay for a refurbished unit
which are going for about $60+ . I got both of my units on their
and fixed them.

[jethro12]

Forgive me if I'm not supposed to do this, but I'm not sure where I'm suposed to post this information; please ignore my other posting of this information as it is under a different model number heading.


Thank you VERY much!
Jeff

Also if your interested I have a parts unit available to repair the one you have.
Digital board works along with the dvd drive. The vcr has intermittent noise
mostly in ep record mode.Sp mode very rarely.

[deuce8pro]

I should have my jvc drm10 back from repair if anyone wants to buy it from me. I sent it in brand new basically just wouldnt record on any dvdrs.

[bvq]

I would look carefully at the 2 x 1Ks that you fitted to the digital board. It would be easy to accidently dislodge the SMT components that you are soldering to or accidently short something out with the solder.

Get a good magnifier and have a close look. Always suspect the last things that you did to the unit. I doubt that it is the PSU Mods that you did.

[bvq]

On another note, has anyone got a schematic for the sound multiplexer and the DVD side tuner on an MV1S?

I cannot get sound from the tuner to the DVD drive although I can get sound from DV in and the external AV connections.

Although mine is a PAL unit with the SCART connectors on the back,I'm guessing that the tuners & sound switching sections are similar to the NTSC units.

There appears to be a CD4052 doing the analogue switching.

PM me if you can email me a scanned page or two.

Thanks in advance.

[jethro12]

On another note, has anyone got a schematic for the sound multiplexer and the DVD side tuner on an MV1S?

I cannot get sound from the tuner to the DVD drive although I can get sound from DV in and the external AV connections.

Although mine is a PAL unit with the SCART connectors on the back,I'm guessing that the tuners & sound switching sections are similar to the NTSC units.

There appears to be a CD4052 doing the analogue switching.

PM me if you can email me a scanned page or two.

Thanks in advance.

Try Trhouse he may give you the schematic.I have a DR-MX1s schematic.On this
it feeds the signal through a BU4052 multiplexer through a series of op amps and then
to a ADC AK5381 then to the pin 73 of DMN8652

[jethro12]

On another note, has anyone got a schematic for the sound multiplexer and the DVD side tuner on an MV1S?

I cannot get sound from the tuner to the DVD drive although I can get sound from DV in and the external AV connections.

Although mine is a PAL unit with the SCART connectors on the back,I'm guessing that the tuners & sound switching sections are similar to the NTSC units.

There appears to be a CD4052 doing the analogue switching.

PM me if you can email me a scanned page or two.

Thanks in advance.

I only have the DR-MX1s schematic. There the audio is fed through the BU4052BCF
multiplexer then through a series of opamps to the ADC aK5381 then to
DMN8652 pin 73 . If you can get a schematic just trace back from
pin 73 since they have the same chip. Can you hear audio when just watching the
tuner on the dvd side but it isn't getting recorded?

[bvq]

I have tried to contact trhouse but without success.

There is no sound when watching the tuner output on the dvd side. The vcr side is fine.

I think that the tuner is ok because if you disconnect the tuner internally and put you finger on the loom to inject hum, no hum is heard. This works on the vcr side.

[trhouse]

bvq,

Sorry for the late reply. I did send you a PM today.

ggoat!!!

I do know someone who sent an M10S to JVC for the "loading" repair a few months ago. It was repaired for free but JVC did ask him for his serial number. JVC's labor rate on the paperwork that came back with the recorder was $100/hour. You can get a guaranteed working, used one off eBay for a "buy it now" price of $60. Even if you want to continue to troubleshoot the bad ones, it is a lot easier if you have one that you know is entirely functional.

[ggoat!!!]

Thanks everyone! Sorry for the late response.

I carefully checked my soldering on the one processor board I attempted to install the 1k resistors on and could find no bridged solder, no loose resistors, no apparent problems. I removed the 1k resistors that I installed, and the board still didn't work in any of my units.

I purchased a 99 cent unit on eBay, which had been refurbished by JVC with a mod'd processor board. It was beat up, but it worked; however, the front panel had problems...you touch it, lights go out, lights come on, some buttons work, some don't, etc...so, I swapped the processor board out into my one unit that I repaired the "loading" problem in (the cap/resistor pb mods) and the unit works as new. So, one down, one to go. Remember, just before I attempted to repair the first unit when it flashed "loading" for the first time the screen went black at that time. So, I'm thinking I didn't actually fry the processor board in that unit; I think that its time was just up at the same time the loading problem appeared. Strange coincidence. The 2nd unit's processor board causes a working/repaired unit (with power supply mods) to go into constant "loading". So, I know that board is fried too.