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From: test on 4 Oct 2006 13:16
Recently got a sony PVM-1954Q that had some bad electrolytics in
it.

I recapped the A board, (132 caps, I won't be doing that anytime
soon again) fired it up and did the alignments according to the
service manual (I have that as well).

The only issue that 'remains' is there are 3 lines, one each for
the red, blue, and green guns at the very top of the picture.
This is evident in all modes, 4:3, 16:9, and underscan. You cant
'see' it in 4:3 mode as it's at the very top of the display but
it's there if you move the picture with the vertical centering.

Wave forms and voltages look normal on IC506, 502, Q507 and Q505.

Picture looks good. All other alignments appear to work correctly.

Just can't get rid of those retrace lines. They look abnormal when
you use the 16:9 or underscan modes.

Anyone ever run across anything like this ?
From: carneyke on 5 Oct 2006 07:28
Ismus be your lucky day ! C584 causes retrace at top of CRT, distorted
(curved corners) in underscan mode = C572 & C592 causes a noisy
picture with excessive jitter. You didn't change all the capacitors or
not in the deflection area. Good Luck


test(a)test.com wrote:
> Recently got a sony PVM-1954Q that had some bad electrolytics in
> it.
>
> I recapped the A board, (132 caps, I won't be doing that anytime
> soon again) fired it up and did the alignments according to the
> service manual (I have that as well).
>
> The only issue that 'remains' is there are 3 lines, one each for
> the red, blue, and green guns at the very top of the picture.
> This is evident in all modes, 4:3, 16:9, and underscan. You cant
> 'see' it in 4:3 mode as it's at the very top of the display but
> it's there if you move the picture with the vertical centering.
>
> Wave forms and voltages look normal on IC506, 502, Q507 and Q505.
>
> Picture looks good. All other alignments appear to work correctly.
>
> Just can't get rid of those retrace lines. They look abnormal when
> you use the 16:9 or underscan modes.
>
> Anyone ever run across anything like this ?

From: Airioch on 5 Oct 2006 11:38
In article <1160047684.164593.290830(a)m73g2000cwd.googlegroups.com>,
carneyke(a)localnet.com says...

> Ismus be your lucky day ! C584 causes retrace at top of CRT, distorted
> (curved corners) in underscan mode = C572 & C592 causes a noisy
> picture with excessive jitter. You didn't change all the capacitors or
> not in the deflection area. Good Luck

Ummmm, yes, I actually replaced all the electrolytics in the chassis
with the exception of one of them, C1515, there's some modification on
the trace side of the board that's covering that particular cap.

Didn't replace any of the polystyrene or dipped mylar..

I'll poke around in that area of the chassis, so some resistance checks
on the associated resistors..

Thanks for the reply..

airi-


>
>
> test(a)test.com wrote:

> > Recently got a sony PVM-1954Q that had some bad electrolytics in
> > it.
> >
> > I recapped the A board, (132 caps, I won't be doing that anytime
> > soon again) fired it up and did the alignments according to the
> > service manual (I have that as well).
> >
> > The only issue that 'remains' is there are 3 lines, one each for
> > the red, blue, and green guns at the very top of the picture.
> > This is evident in all modes, 4:3, 16:9, and underscan. You cant
> > 'see' it in 4:3 mode as it's at the very top of the display but
> > it's there if you move the picture with the vertical centering.
> >
> > Wave forms and voltages look normal on IC506, 502, Q507 and Q505.
> >
> > Picture looks good. All other alignments appear to work correctly.
> >
> > Just can't get rid of those retrace lines. They look abnormal when
> > you use the 16:9 or underscan modes.
> >
> > Anyone ever run across anything like this ?
>
>
From: Airioch on 5 Oct 2006 14:46
In article <1160047684.164593.290830(a)m73g2000cwd.googlegroups.com>,
carneyke(a)localnet.com says...

> Ismus be your lucky day ! C584 causes retrace at top of CRT, distorted
> (curved corners) in underscan mode = C572 & C592 causes a noisy
> picture with excessive jitter. You didn't change all the capacitors or
> not in the deflection area. Good Luck
>

Removing and measuring the components in that area shows them
all to be well within tolerance with one possible exception.

L515 as indicated on the schematic should be, at least according to
what's on the paper, 12uH. Looking in the parts list only gives a sony
part number, going by what's indicated on the schematic, L515 is way out
of spec, I'm measuring 12.38mH (wavetek LCR55).

I'm hoping that it's a misprint on the schematic, that's a pretty large
amount to be out, I'd expect more than a couple of retrace lines at the
top of the display..

airi-


>
> test(a)test.com wrote:
> > Recently got a sony PVM-1954Q that had some bad electrolytics in
> > it.
> >
> > I recapped the A board, (132 caps, I won't be doing that anytime
> > soon again) fired it up and did the alignments according to the
> > service manual (I have that as well).
> >
> > The only issue that 'remains' is there are 3 lines, one each for
> > the red, blue, and green guns at the very top of the picture.
> > This is evident in all modes, 4:3, 16:9, and underscan. You cant
> > 'see' it in 4:3 mode as it's at the very top of the display but
> > it's there if you move the picture with the vertical centering.
> >
> > Wave forms and voltages look normal on IC506, 502, Q507 and Q505.
> >
> > Picture looks good. All other alignments appear to work correctly.
> >
> > Just can't get rid of those retrace lines. They look abnormal when
> > you use the 16:9 or underscan modes.
> >
> > Anyone ever run across anything like this ?
>
>
From: stratus46 on 6 Oct 2006 00:34
test(a)test.com wrote:
> Recently got a sony PVM-1954Q that had some bad electrolytics in
> it.
>
> I recapped the A board, (132 caps, I won't be doing that anytime
> soon again) fired it up and did the alignments according to the
> service manual (I have that as well).
>
> The only issue that 'remains' is there are 3 lines, one each for
> the red, blue, and green guns at the very top of the picture.
> This is evident in all modes, 4:3, 16:9, and underscan. You cant
> 'see' it in 4:3 mode as it's at the very top of the display but
> it's there if you move the picture with the vertical centering.
>
> Wave forms and voltages look normal on IC506, 502, Q507 and Q505.
>
> Picture looks good. All other alignments appear to work correctly.
>
> Just can't get rid of those retrace lines. They look abnormal when
> you use the 16:9 or underscan modes.
>
> Anyone ever run across anything like this ?

Firts thing, you went WAY overboard on the caps thing. As others said,
C572 and C584 are the most common bad ones. There are a couple others I
check in the sweep area, C588, C590 and a few others. Get an ESR meter
and you'll save scads of time.

Your 'retrace' lines are not retrace lines. Those are the beam current
feedback measurements and if you get rid of them, it will look
terrible. In NTSC they fall on lines 17,18,19 - RGB respectively. You
measure TP403 with a scope and set G2 until the lowest value of those 3
lines is +1.35 volts.

Do you have the service manual? It explains most of this though the
schematics are drawn poorly.

GG

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