Sony DVP-CX860 DVD Player Problem on MB-94 Board.

Ok heres the problem, i have something pulling down my power
supply on the MB-94 Board.

I have swapped parts from other decks to figure it out this far.
And i am 100% certin the problem is on this board.
Unfortunatlly it contains about 13 I.C.'s and a ton of
Surface mount Components.
I looked closly at the eloctrolytic caps and i cant see any
of them oozing.
Has anyone here come across a similar situation on this deck
or perhaps a different ceck that uses the same MB-94 Cpu Board??

Symptom is that the power supply is getting pulled down imeaditly
no display no nuttin. but as i said before...all parts and board in this deck work
just fine...i have it isolated to the MB-94 Board.
So i would appreciate responses that ONLY would help in this board.
not any other parts of the machine.
Thanks in advance

Electrolytic caps do not have to leak liquid to be shorted or high in
ESR. The expression of a leaky component, really came from that it has
some DC resistance when it should not, or in other words it is leaking
DC resistance. Since caps are in theory a purly reactive device, they
should idealy not have any DC resistance. A leaky cap, would therefore
have some DC leakage resistance, and thus be considered leaky.
Nothing would be oozing out of it in this case. Since no components
are absolutely perfect, most caps will exibit some DC resistance, but
this would be in the very high omage range, which is far beyond having
an adverse effect for its application when not defective.

These boards are complex and can be expensive to servce at the
component level. They can also be very time consuming to service. At
the factory service when these machines are under warranty, they
usually change the complete board, and toss the old one, unless it is
a simple problem.

A simple approach that may help, is to measure the DC resistance to
ground, on all the supply inputs. Look for a resistance that is too
low, and try to trace from there. Most of the time, it would be a
decoupler capacitor that is shorting the supply directly to ground. If
there are any voltage regulator IC's, check these out as well. If it
is not this, then the problem may be on the sophisticated side to
locate.

Jerry Greenberg
http://www.zoom-one.com

--

"Mr Bungle" Mr wrote in message . net...
Sony DVP-CX860 DVD Player Problem on MB-94 Board.

Ok heres the problem, i have something pulling down my power
supply on the MB-94 Board.

I have swapped parts from other decks to figure it out this far.
And i am 100% certin the problem is on this board.
Unfortunatlly it contains about 13 I.C.'s and a ton of
Surface mount Components.
I looked closly at the eloctrolytic caps and i cant see any
of them oozing.
Has anyone here come across a similar situation on this deck
or perhaps a different ceck that uses the same MB-94 Cpu Board??

Symptom is that the power supply is getting pulled down imeaditly
no display no nuttin. but as i said before...all parts and board in this
deck work
just fine...i have it isolated to the MB-94 Board.
So i would appreciate responses that ONLY would help in this board.
not any other parts of the machine.
Thanks in advance
--

Well, if that board is loading down, say, a 5 volt line, I would connect an
external power supply between that line and circuit ground, and see what
gets hot.

Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Mr Bungle" Mr wrote in message
news Sony DVP-CX860 DVD Player Problem on MB-94 Board.
Ok heres the problem, i have something pulling down my power
supply on the MB-94 Board.

I have swapped parts from other decks to figure it out this far.
And i am 100% certin the problem is on this board.
Unfortunatlly it contains about 13 I.C.'s and a ton of
Surface mount Components.
I looked closly at the eloctrolytic caps and i cant see any
of them oozing.
Has anyone here come across a similar situation on this deck
or perhaps a different ceck that uses the same MB-94 Cpu Board??

Symptom is that the power supply is getting pulled down imeaditly
no display no nuttin. but as i said before...all parts and board in this
deck work
just fine...i have it isolated to the MB-94 Board.
So i would appreciate responses that ONLY would help in this board.
not any other parts of the machine.
Thanks in advance

Thanks jerry, basicly what your saying i guess is to change the caps
and see what happens, scince i dont have an ESR meter, (P.S. Who ,sells
a good inexpensive one?) I thinks the easiest approach for me is to cange
the
little buggers one by one. Really not much else i can do here.
there are so many IC on this thing, i dont want to risk blowing them out
by trying Marks approach to things, and letting them "fry".
I priced a new PC board. it would be around $300 or so.
Does anyone else know of what other model numbers might also use this Board
inside??
Cant just be this one Player!?1?


"Jerry Greenberg" wrote in message
om...
Electrolytic caps do not have to leak liquid to be shorted or high in
ESR. The expression of a leaky component, really came from that it has
some DC resistance when it should not, or in other words it is leaking
DC resistance. Since caps are in theory a purly reactive device, they
should idealy not have any DC resistance. A leaky cap, would therefore
have some DC leakage resistance, and thus be considered leaky.
Nothing would be oozing out of it in this case. Since no components
are absolutely perfect, most caps will exibit some DC resistance, but
this would be in the very high omage range, which is far beyond having
an adverse effect for its application when not defective.

These boards are complex and can be expensive to servce at the
component level. They can also be very time consuming to service. At
the factory service when these machines are under warranty, they
usually change the complete board, and toss the old one, unless it is
a simple problem.

A simple approach that may help, is to measure the DC resistance to
ground, on all the supply inputs. Look for a resistance that is too
low, and try to trace from there. Most of the time, it would be a
decoupler capacitor that is shorting the supply directly to ground. If
there are any voltage regulator IC's, check these out as well. If it
is not this, then the problem may be on the sophisticated side to
locate.

Jerry Greenberg
http://www.zoom-one.com

--

"Mr Bungle" Mr wrote in message
. net...
Sony DVP-CX860 DVD Player Problem on MB-94 Board.

Ok heres the problem, i have something pulling down my power
supply on the MB-94 Board.

I have swapped parts from other decks to figure it out this far.
And i am 100% certin the problem is on this board.
Unfortunatlly it contains about 13 I.C.'s and a ton of
Surface mount Components.
I looked closly at the eloctrolytic caps and i cant see any
of them oozing.
Has anyone here come across a similar situation on this deck
or perhaps a different ceck that uses the same MB-94 Cpu Board??

Symptom is that the power supply is getting pulled down imeaditly
no display no nuttin. but as i said before...all parts and board in this
deck work
just fine...i have it isolated to the MB-94 Board.
So i would appreciate responses that ONLY would help in this board.
not any other parts of the machine.
Thanks in advance
--