[TechAssist] Re: CTC169
- From: "Damon" <DAMON101@xxxxxxxxxxxxxx>
- To: <techassist@xxxxxxxxxxxxx>
- Date: Wed, 28 Nov 2001 22:19:08 -0500
Ok, let's see if we can check a few more things out in regards to the
PINCUSHIONING:
First: East-West Pincushioning
Check cr4402 the Pin Damper, you've already replaced c4402.
Next check and see if your width adjust actually works, you should be able
to swing the sides about 3-4 inches each side. If not:
U 4801 and Q4802 are located behind the horiz output's heat sink. Pincushion
signal should be present on pin 7 of u4801, +26 v supply on pin 8. Pin 3 is
e/w pin amp input, pin 2 is width.
Q 4802 is output for pin amp u4801. collector should have 13.7 volts dc and
pin signal present.
Second: Vertical Pincushioning
There isn't much to this: T4301 pin 6 and 1 couples horiz drive signal to
the vertical circuit thru pin 2 and 3 of the IHVT T4401. Personally I don't
believe this is the source of Vert Pin Correction, I think that comes from
the Convergence Board. Check and wiggle the connectors on the Convergence
board, this has been a known failure point. RCA has a kit available for
this. However I have never seen this cause Vertical Pincushioning, just
misconvergence that is erratic.
Damon Brunger
damon101@xxxxxxxxxxxxxx
Telrad Electronic Services
Ft Wayne, IN 46815
----- Original Message -----
From: "joel e sanford" <rope23@xxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Cc: <techassist@xxxxxxxxxxxxx>
Sent: Wednesday, November 28, 2001 11:08 AM
Subject: [TechAssist] Re: CTC169
>
> I have been working on ONE Rca 169 for what seems like TEN years,! wish
> I could find a bad cap (or something) have received informatiuon from
> every (I do mean EVERY) body on the list nothing seems to help find the
> prob!from Dan Mundy the complete print of all suspect circuit,s read them
> metered them all voltages within ...from Tech lind- suggestion to chang
> plugs -no..from Clint to check items (all voltages on the pin
> outputcorrectso.........)I want to stand this projo up against the wall
> and shoot it but .... the customer thinks it,s my fault.it came in dead,
> had the 169mod rebuilt, then trippler shorted befor i could look at the
> raster. wasited a Looonnnnnnnng time for the trippler, and now this
> .pinchusion bowed top and bottom(c4402 did not cure thanks dennis
> enyway)also some parabolic distortion on both sides....enybody seen this?
> PTV adapter also rebuilt all voltages on D-conv,with
> specsnot a yoke prob because each gun has the almost same distortion.I
> don,t want to rant on (will put someone to sleep)BUT.........Sanford
>
>
>
> On Tue, 27 Nov 2001 20:47:38 -0600 Bill Grabowski <bgrabowski@xxxxxxxxx>
> writes:
> >
> > I've been working on CTC169's for ten years but I never found a
> > leaky
> > cap that I
> > can think of......
> >
> > Bill Grabowski
> > Triangle Appliance
> >
> >
> > "Leonard G. Caillouet" wrote:
> > >
> > > I am wondering if you all have seen many leaky caps in these sets.
> > I just
> > > did two this week that had leaky Nichicon 105 degree caps. The
> > electrolyte
> > > caused enough corrosion to damage a couple of traces. These are
> > the first I
> > > have seen like this and am wondering if we can expect this to be
> > as common
> > > as in the Hitachi and Misubishi projection sets. How far do you
> > guys go in
> > > looking for other caps going bad on these sets. I have found that
> > sometimes
> > > the only way that you can find them is to heat the pins and see if
> > they
> > > smell or remove them and visually inspect them. Many of the ones
> > that are
> > > starting to leak check OK on all four tests, capacitance, ESR, DA,
> > & leakage
> > > current. Should we be checking all of them on these sets?
=================================
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