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-   -   JVC DR-MH30 'Loading' error, power problem? (https://www.digitalfaq.com/forum/vcr-repair/3778-jvc-mh30-loading.html)

Anaksanamune 12-29-2011 11:33 AM

JVC DR-MH30 'Loading' error, power problem?
 
Another DR-MH30 problem...

I have a background in electronics (design work) and computing, but no consumer repair experience, so I am hoping for some direction.

Recently we bought a new faulty freezer, that tripped the house fuse box several times before being sent back.
This power interruption seems to have killed off my DR-MH30, and I am stuck with the fabled Loading screen.

Not really sure where to start looking. Only clues are...

I have 3 16v 470uF caps that are slightly bulging and have brown crust on the tops, although I assume these are an older problem (should they be replaced?).

For the first 5 seconds once the power has been connected there is a loud repeated clicking noise that started with the breakdown (sounds like a relay), this clicking stops once the fan kicks in (and I assume the system has loaded).
Sometimes when plugged in the DVD / HDD lights will briefly flash on and then nothing at all else will happen at all.

Note: I live in the UK and this in the PAL version.

Any advise on what (and where) to start testing would be helpful, as well as general ideas etc about what could be causing the problem.

Thanks
Anak

kpmedia 12-29-2011 12:13 PM

Hi Anak, welcome to the site. :)

Quote:

Originally Posted by Anaksanamune (Post 18669)
I have 3 16v 470uF caps that are slightly bulging and have brown crust on the tops, although I assume these are an older problem (should they be replaced?).

Yes, start by doing this. It's a low-cost fix, if you have any skills with a soldering iron. (I most assuredly do not, but I know enough friends and family that are skilled enough to perform caps replacements on my behalf.)

Quote:

For the first 5 seconds once the power has been connected there is a loud repeated clicking noise that started with the breakdown (sounds like a relay), this clicking stops once the fan kicks in (and I assume the system has loaded).
Open the unit and listen for a specific location, the origin of the sound. Is it the hard drive? (I hope not, for your sake.)

Quote:

Sometimes when plugged in the DVD / HDD lights will briefly flash on and then nothing at all else will happen at all.
This points to the caps.

Keep us updated on what you find, regarding the clicking noise, after opening the unit.

Anaksanamune 12-30-2011 07:11 AM

Thanks for the fast reply.

The clicking is not the hard drive, it seems fine. Although from what I gather it can be a nightmare if it goes. So is there a way to back it up while it works? and is it worth it?

I can't pinpoint the noise exactly.
Its close to where the power goes into the device. I'm not sure how familiar you guys would be as it is a 230-240V supply here so the circuitry may be different.
Anyway, there is what looks like two small transformers and something (maybe a thyristor) mounted to a heat sink. One of these or something close by is where the sound is coming from.

lordsmurf 12-30-2011 11:27 AM

I'm not aware of any way to backup the hard drive.

I have a JVC disc ISO that's supposed to repair a PAL hard drive (special disc that formats a blank replacement drive), but I don't seem to be able to find it. I'm afraid it's been dumped into the shared unsorted research folder for digitalFAQ.com, meaning it's a needle in a hay stack right now. That research is scheduled to be sorted in the spring (2012), so it will be posted when sorted and located.

Might sound be emanating from a capacitor? Given the higher current, the noise could be quite loud.

GDogTech 11-15-2013 07:46 PM

I know this is a VERY old thread; I ran across it just by chance. My reply is not on the main topic of the thread either, but it was discussed here. If anyone is still interested in fixing/cloning their DR-MH20/30/50, I might be able to help you. I have successfully cloned my MH30. It is not that hard to do with the right HW & SW AND the correct replacement HDD. My MH30 is running right now on the cloned HDD with the original HDD stored away as a backup/spare. So, if anyone *is* interested, I would be willing to put together some instructions and maybe even some physical help if need be - just let me know.
-Gary
PS: LS, if you would rather I post this as a new thread, just let me know & I will oblige. I'm just not sure there is still any interest in this topic.

lordsmurf 11-15-2013 07:57 PM

It's not that old. :)

What can be cloned to files? Perhaps there are image files that can be used on this? If so, attach them/ Or if the files are too large, we can provide FTP space. Something like this is definitely something we want to archive. The JVC line of DVD recorder hardware was the best of its class, and keeping them going is what us JVC owners all want to see.

GDogTech 11-15-2013 08:47 PM

Here's what has to be done ...
 
Hi LS,
Basically, you have to do a RAW (sector by sector) backup of a GOOD HDD to another HDD. It is best to do this as a preventative measure while your old HDD is still operable. If not, then you will need a good RAW image to restore from. I *might* be able to supply one, but it would be only for the MH30 as it is all I have. You will need a larger HDD than the one you are cloning as this form of backup creates MEGA-HUGE, uncompressed files. The backed up file is a bit larger than the entire HDD capacity. I used a 200GB HDD for this. Then you have to restore it to a PERFECT (ZERO defective sectors) HDD that is the EXACT same model. In my case, it was a "Maxtor DiamondMax 16 160GB ATA/133 3.5" QUICKVIEW". Key word here is QUICKVIEW. These can usually be found on ebay from time to time. There are three sellers of them on ebay right now. Here's a link to one of them:

http://www.ebay.com/itm/MAXTOR-DIAMO...item43c1f547ce

I would recommend buying at least TWO of them to make sure you get one that is defect free. I did that and subsequently sold the one I didn't need.

ALSO, I seem to remember something about attaching the cloned HDD to a Windows 7 machine and changing the Drive ID to match the old one. Although I may be confusing this with some other similar procedures I have done in the past. However, I could always pull the HDD currently in the MH30 now and check its ID against the one I have in storage. I have some paperwork on this somewhere; I just need to track it down.

I would be willing to make another RAW backup of my spare HDD for the group, but it would be something like 180GB, so I would not be wanting to UPload something that large. Maybe you could send me an old HDD of sufficient size and I could do it directly on that. Funny thing is I kept that RAW image on that 200GB HDD for like 18-months before I eventually re-purposed it to another project. Wish I hadn't done that now.

What would REALLY be cool is if there were a way to somehow get a LARGER HDD into my MH30, like 500GB or larger. I seem to remember reading something about this somewhere, but not having the time to pursue it, it got lost. I will look for the article however. I usually print things like that out, but I have many boxes full of articles like that. :o

So, where do you want to go from here?
-Gary

GDogTech 11-16-2013 03:22 PM

Just wanted to add a couple of things that interested members might find useful. I got a lot of my information on this topic from a UK website called Andy's Techie Stuff. It is hosted by a retired JVC Service Technician, Andy Wilks, so he really knows these machines. Here is one of the more informative links:

http://www.cippico.com/bbs/viewtopic...asc&highlight=

He wants everyone to join the Forums to do much of anything, but he is responsive and very friendly and helpful. He has said on the site that there is not much activity anymore, so he is not sure how much longer he is going to keep it up. It is up & running right now however.

LS: as a relevant site owner yourself, you might be able to approach him about transferring some or all of the data he has on these machines. He has much NTSC as well as PAL. He also, by his own words, has mountains of data on many different JVC Models that is not even on the site. He was the one that supplied me with the Service Manual and Schematics for my DR-MH30 and DR-M100. I couldn't find this data anywhere else on the web.

It just occurred to me that I have never heard this site mentioned on any Forums I subscribe to, so I thought I would tell everyone about it. Hope it helps someone ...
-Gary


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