DR-MH300SE starts after plug in, but then does nothing

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efect2000
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DR-MH300SE starts after plug in, but then does nothing

Post by efect2000 » Sun Mar 03, 2013 11:50 am

Hello, I have this MH300, which after plugged in starts "please-wait", I can hear as the hdd runs and works, if while starting I press the open tray, it opens.
After a while, it stops and remain normal, display light less and the vps in red is "on", If I push play button on the unit, I can see how it "asks" me for the rm code, shows the actual and if I push any key on the rm, it changes to the new.

I have changed all the capacitors on the ps part, even the "little", 5 and 12 volts look ok, except Sw12v (on C5310) that are between 10 and 10,5.
I have connected an external power supply on cathode of 5203 (in fact the schema I have is not as the real machine, some components are not like drawn) and checked that I have then 12v on C5310, but it makes the same.

Once the unit has started and stops inicializing, lighs decreases and after a while it decreases more and blinks, as if any voltage were lower, but as the ps is on tha main board, I can do any test on 3,3 and other voltages.
Fan does not runs never, unless I short c-e in q5304, then it runs.

Any idea if it is possible fix? I thought to cut the lowest part of the metal box, in order to have full access on the main board, as the hdd/dvd control unit I have seen, that the metal is the heatsink of the circuits, or at least that looks to me.

Thank you for reading

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andywilks
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Post by andywilks » Mon Mar 04, 2013 3:48 pm

10.5 v is probably ok on the 12v rail.

Are you saying it completes the initial boot up ok? yes I think.
Then when you turn on, display comes on etc yes.
then it soon crashes and goes back to 'loading' or 'please wait' ?

fan control..... should be on when machine is actually on and running, stopped in standby.

So what is still wrong? Not sure, but if it boots up , the hdd operating system is ok and readable. a 'blip' or ripple on a voltage rail will cause a crash. add extra little capacitors to the 12v and 5v pins to the cdrom drive maybe just to get a bit more smoothing

Andrew

efect2000
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Post by efect2000 » Mon Mar 04, 2013 6:16 pm

thankyou for answer.

My explanation in english is not so good as I wish, because I'm spanish.

I plug 220, it starts booting, on display appears "please" and "wait", meanwhile the fan does not run (in others mh20/mh30 it does) it finishes the boot, and if I quickly press play button on the item , I can change the code of the remote.

If I do nothing, after a while (3 seconds) the display becomes darker and blinks until it "dissapears".

I have insert a cd of JVC adviser for mh 30 and on tc screen appears image, (blue with JVC letters) I don't remember what happens after, but the test does not go on.

I have put another dvd device and makes the same, have also put capacitors in the dvd and hdd connector and the same.

when I push on the unit or in the rm the ON button, it does nothing, as if I did nothing. I have tried another remote too.

does exist any jvc dr-mh20 soft AdviserV127 for this unit? or this one should work?

thank you very much.

efect2000
Posts: 19
Joined: Sun Sep 05, 2010 9:57 am
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Post by efect2000 » Sun Mar 10, 2013 4:17 pm

hello again.

Well, yesterday I pressed on the rm the key "VPS" and then it worked :oops: :lol:

but now there is another problem, it starts perfectly, while it starts, on the tv screen appears the "scene" DVD video recorder" perfectly, but thes the image appears distorted, as if tehre were ripple in analog.
Can i upload an photo on imageshack or similar site?
If I record with a dvd disc, then it records perfectly when played into another device (an mh30)
thank you

efect2000
Posts: 19
Joined: Sun Sep 05, 2010 9:57 am
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Post by efect2000 » Sun Mar 17, 2013 10:49 am

well, it looks that the problem comes from the digital board, as there the video already is distrorted.

thank you

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