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[DVL-909] Won't power on
https://forum.lddb.com/viewtopic.php?f=55&t=7969		 Page 1 of 1
Author:  henrikwils [ 08 Aug 2018, 14:05 ]
Post subject:  [DVL-909] Won't power on
My Pioneer DVL-909 (EU model with old logo) was working fine for some time, but all of a sudden no longer turns on. No lights or anything - it appears completely dead.

I had a technician look at it, and he believes that the power supply is good, but it shuts off, because of some other problem that it detects.

Does anyone have any clue what could possibly be wrong, and how to fix it?
Author:  krbahr [ 09 Aug 2018, 00:18 ]
Post subject:  Re: [DVL-909] Won't power on
The technician needs a schematic and multi-meter to start following power lines to find the problem. No easy fix.
Author:  blam1 [ 09 Aug 2018, 15:52 ]
Post subject:  Re: [DVL-909] Won't power on
Nothing to see here. Keep moving
Author:  kaflo [ 15 Aug 2018, 00:30 ]
Post subject:  Re: [DVL-909] Won't power on
If you plug it in and switch it on and it does NOTHING and no LED comes on then the power supply is not o.k. Check R103 and if it is blown, also check Q101.

If some LED comes on, check the little fuses that are soldered on the board.
Author:  yaffle2345 [ 19 Mar 2019, 00:07 ]
Post subject:  Re: [DVL-909] Won't power on
I'm having a similar problem with my 909 - it's completely dead.

I should say I don't know much about electronics, but I do have a multimeter - how difficult can it be? :-)

The board's a VWR1287 and all the fuses (7 little ones and the big one) seem fine.

On the outputs:

CN202 has +14V on pin 2, +5V on 10 and -27V on 14. But the +5V on 4 and the +3.3V on 7 and 8 all seem to be 0V
CN203 has -14V & +14V on 2 & 3, but the +5V & -5V on 6, 7, 8, & 9 are all 0V.

There seems to be a little darkening on the board around resistors R105, R106 & R109, as if they've been very hot, although they don't show as being open-circuit (although I don't know if that can be said for certain while they're on the board).

If anyone has any advice on the best way to proceed, it would be much appreciated :-)

The post above mentions checking Q101, what's the best way to check a voltage regulator, do I have to test the voltages with the power supply connected? What voltages should I expect to see there?
Author:  framal [ 29 Mar 2019, 00:41 ]
Post subject:  Re: [DVL-909] Won't power on
yaffle2345

Ic311 which supplies 5v and Ic411 which supplies 3.3v each have a CT pin which require a 2v switching signal to switch from STANDBY to ON.

That signal is controlled from the remote and is only operational when the power supply board is installed in the laser disc player.

The darkening, on the pc board, around R105,R106 & R109 is not uncommon.These resistors,all 68k,form a voltage divider across the rectified

mains DC.They,along with C116, provide the KICK START for the SMPS.Please check C116,1mfd/400v, for both ESR and capacitance.

The ESR reading should be a low value, approximately 7-8, and the capacitance should be approximately 1mfd.If in doubt change it.

I recommend that you also check the filtering capacitors,C211,C611,C311,C312,C511&C512 on the power supply secondary.If any are faulty

they can affect the supply's operation.Q101,Q150&Q151 are all N channel mosfets,ShinDengen 2SK2333.
Author:  yaffle2345 [ 29 Mar 2019, 18:15 ]
Post subject:  Re: [DVL-909] Won't power on
framal wrote:
yaffle2345....
Thanks very much for the reply, there's a lot of information in there which I'll be working through as soon as I have some spare time :-)
Author:  yaffle2345 [ 07 Apr 2019, 12:32 ]
Post subject:  Re: [DVL-909] Won't power on  Topic is solved
framal wrote:
These resistors,all 68k,form a voltage divider across the rectified mains DC.
They,along with C116, provide the KICK START for the SMPS.Please check C116,1mfd/400v, for both ESR and capacitance.
The ESR reading should be a low value, approximately 7-8, and the capacitance should be approximately 1mfd.If in doubt change it.
Just to follow up, I removed C116 and replaced it (not having the equipment to check it as indicated), and that fixed the problem - thanks, very happy :-)
Author:  admin [ 07 Apr 2019, 12:48 ]
Post subject:  Re: [DVL-909] Won't power on
yaffle2345 wrote:
Just to follow up, I removed C116 and replaced it (not having the equipment to check it as indicated), and that fixed the problem - thanks, very happy :-)


Thank you for the update!

DVL-* power issues seem to be very common. Having (confirmed) ways to potentially save them always sounds great!

Julien
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