CT169 board :)
 

Hi Guys...

Swallow your coffee or beer before you read this or
you're gonna ruin your monitor... you've been warned :)

Went for a walk Sunday morning... came upon a yard sale.
Nice rca tv sitting there, sign said not working, not
worth repair, for parts only. Ten bucks.

Asked the fellow what was wrong with it, he said works
for about 10 minutes, then it "squishes down to the middle"
for a while, then back, ad nauseum.

Said to myself, aha - a bit of solder and it's in business.

Picked it up today, and runs beautifully, looks fantastic,
sounds fantastic- but only for 10 minutes. Some percussive
maintaince brings it back just fine.

Now swallow. I can't get the board out of the case! :)

I easily removed the board support, but now can't budge
the board in its slot. Tight as a drum, can't budge it.
Slip a screwdriver between the case and board and twist
and it might budge a hair, but gonna break before it comes
out. Any of you know of the secret?

Shoulda mentioned, if there's a difference this one says
home theater on it... external speaker terms on the back
panel and so on.

Now it's half apart on the dining room table :)

Thanks, and take care.

Ken

Nothing holds the 169 in there only sticky dirt on the track..

kip
"Ken Weitzel" wrote in message
news:tWHte.1755411$6l.655817@pd7tw2no...

Hi Guys...

Swallow your coffee or beer before you read this or
you're gonna ruin your monitor... you've been warned :)

Went for a walk Sunday morning... came upon a yard sale.
Nice rca tv sitting there, sign said not working, not
worth repair, for parts only. Ten bucks.

Asked the fellow what was wrong with it, he said works
for about 10 minutes, then it "squishes down to the middle"
for a while, then back, ad nauseum.

Said to myself, aha - a bit of solder and it's in business.

Picked it up today, and runs beautifully, looks fantastic,
sounds fantastic- but only for 10 minutes. Some percussive
maintaince brings it back just fine.

Now swallow. I can't get the board out of the case! :)

I easily removed the board support, but now can't budge
the board in its slot. Tight as a drum, can't budge it.
Slip a screwdriver between the case and board and twist
and it might budge a hair, but gonna break before it comes
out. Any of you know of the secret?

Shoulda mentioned, if there's a difference this one says
home theater on it... external speaker terms on the back
panel and so on.

Now it's half apart on the dining room table :)

Thanks, and take care.

Ken

There's probably dirt holding it back.

The cause is usually from bad capacitors in the vertical deflection
circuit. With age, they can become thermo sensitive. You can find these
with a heat gun, cooling spray, and an ESR meter.


Jerry G.
======

You've taken the three 1/4" screws off the back panel that holds it to
the frame and flexed the plastic holders on each side of the back panel
outwards to release the chassis? That's all there is. Solder the bad
connections after scraping any glue off the top of the chassis which is
easier said than done, and you'll have a nice set.

kip wrote:

Nothing holds the 169 in there only sticky dirt on the track..

Hi Kip...

Thanks! Naturally you're right.

Perhaps this is the first time this one's been out... sprayed
it with a little wd-40 just to wet it and it slowly but
surely jerked out... inch by inch. Tough part is keeping
it going straight.

Anyway, appears to be old dry sticky left over flux on
the edge of the board.. gonna gently sand it off in case
it needs to come out again.

Thanks again, and take care.

Ken

Jerry G. wrote:

There's probably dirt holding it back.

The cause is usually from bad capacitors in the vertical deflection
circuit. With age, they can become thermo sensitive. You can find these
with a heat gun, cooling spray, and an ESR meter.

Hi Jerry...

Thanks very much, appreciate it. Seemed to be extra dried
up flux on the edges of the board.

Hoping that just a reflow will do, given that I can turn it
on and off with just a bit of a tap on the case, but if not
I'll be sure looking at the caps :)

Oh - one more thing... I retired before these things came
out... wouldn't mind touching it up while I'm at it.
Is there no longer a service switch (or jumper) to
completely collapse vertical?

Thanks again, and take care.

Ken

I'm a pro, and don't just mean I get paid. That back panel on the
CTC169 is to be removed for service. Others don't do this. There is a
metal frame on the board and between that and other things you can keep
the pressure even when you pull. This is impossible when the plastic is
in place.

Anything stickying up the wicket makes it all worse. Once I get my
hands in the right place and pull, if it doesn't come I cut the rails.

RCA is great with this mounting, you spill one drop of Coke into it and
it's wrecked. I worked on a CTC140 one time that had the foils peeled
off in those tracks.

I always take the plastic shield off a CTC or PTK169 before anything.
Now realize that I can troubleshoot any of these chassis' with a dead
set symptom in about 2 minutes after that, if even that long. I have
literally worked on hundreds of them. I am telling you, remove the
plastic backshield from the chassis. Failure to do so can result in
overstressing the SMD components at the very least. Then you get
intermittents that can be very hard to solve.

On your last point, none of us use, well to my knowledge, service
switches, even if they exist. You use the G2 and bias to get color
balance with the contrast all the way down and the brightness at
factory default. The color is all the way down, you get a balance down
there, and make SURE you don't have retrace lines, then you crank the
contrast and the drives (on that chassis it is red/blue differential
and green), are what balances the high brightness areas. Some find it a
bit difficult to work with this setup, but not all.

There is a master setup procedure for all sets. I'll tell you but not
now. I must go.

The old bed/worktomorrow cross.

JURB

Ken Weitzel wrote:

Hi Jerry...

Hoping that just a reflow will do, given that I can turn it
on and off with just a bit of a tap on the case, but if not
I'll be sure looking at the caps :)


Ken, your instincts are correct, it's not caps. Occasionally, you'll
find the vertical yoke coupling cap (high value) vented, but it won't
intermitt. I've had several 169s that had bad connections causing
vertical loss.


Oh - one more thing... I retired before these things came
out... wouldn't mind touching it up while I'm at it.
Is there no longer a service switch (or jumper) to
completely collapse vertical?



I think the 169 has a software service switch. Try holding down the
menu while plugging the TV in, or holding the menu when turning it on.
Like Jeff says, the best gray scale tracking is usually achieved
without a service switch. Older CRTS don't track perfectly, so setting
up the base screens is best done with the contrast to zero, and the
picture dim. This will give you a different setting than if you did
the same using a service switch, which kills *all* video. You'll then
find that when you adjust the drives for best whites, it's sometimes
advantageous to fudge the screens again, then back to the drives again.


John

On 21 Jun 2005 04:53:13 -0700, "John-Del" wrote:



Ken Weitzel wrote:

Hi Jerry...

Hoping that just a reflow will do, given that I can turn it
on and off with just a bit of a tap on the case, but if not
I'll be sure looking at the caps :)


Ken, your instincts are correct, it's not caps. Occasionally, you'll
find the vertical yoke coupling cap (high value) vented, but it won't
intermitt. I've had several 169s that had bad connections causing
vertical loss.


That's one strange thing I noticed in my 6 or so years in this
business...the most typical, multi-manufacturer failure of all, the
cap causes vertical IC to fail...was not typical at all of most of the
larger TCE sets.

Tom


Oh - one more thing... I retired before these things came
out... wouldn't mind touching it up while I'm at it.
Is there no longer a service switch (or jumper) to
completely collapse vertical?



I think the 169 has a software service switch. Try holding down the
menu while plugging the TV in, or holding the menu when turning it on.
Like Jeff says, the best gray scale tracking is usually achieved
without a service switch. Older CRTS don't track perfectly, so setting
up the base screens is best done with the contrast to zero, and the
picture dim. This will give you a different setting than if you did
the same using a service switch, which kills *all* video. You'll then
find that when you adjust the drives for best whites, it's sometimes
advantageous to fudge the screens again, then back to the drives again.


John

On Tue, 21 Jun 2005 20:12:27 GMT, Tom MacIntyre
wrote:

On 21 Jun 2005 04:53:13 -0700, "John-Del" wrote:



Ken Weitzel wrote:

Hi Jerry...
Ken, your instincts are correct, it's not caps. Occasionally, you'll

That's one strange thing I noticed in my 6 or so years in this
business...the most typical, multi-manufacturer failure of all, the
cap causes vertical IC to fail...was not typical at all of most of the
larger TCE sets.

Tom

Tom, you're correct. Vertical failures is extremely rare in those.
It had to do with the vertical design RCA has done to it made the
vertical circuit failure tolerant so well.

Cheers, Wizard

Hah ! After 25 years, last week I saw my very first vertical failure on
a 169. They are very rare. This was a real one, last time it was the
degaussing transistor, as it kills vertical during degauss. Technically
that one wasn't really vertical failure.

JURB

On 24 Jun 2005 16:58:07 -0700, wrote:

Hah ! After 25 years, last week I saw my very first vertical failure on
a 169. They are very rare. This was a real one, last time it was the
degaussing transistor, as it kills vertical during degauss. Technically
that one wasn't really vertical failure.

JURB


Yeah, I did mean rare. Anyway, I have a stubborn 169 CTV with
intermittent vertical collapse. Already resoldered whole area. Yes I
made sure of no glue there!

Cheers, Wizard

On 24 Jun 2005 16:58:07 -0700, wrote:

Hah ! After 25 years, last week I saw my very first vertical failure on
a 169. They are very rare. This was a real one, last time it was the
degaussing transistor, as it kills vertical during degauss. Technically
that one wasn't really vertical failure.

JURB

I saw one, in only 5-6 years of work...it was a low-value resistor on
the input to the vertical IC, and was it fussy! It required the exact
value, or the vertical was not corrected. I didn't have the exact
value at the time, and tried the next one, and it just didn't do the
job. I think the resistor was in the 4.7-5.6 ohm range.

This is almost like a rare bird sighting, isn't it? :-)

Tom

On Tue, 21 Jun 2005 01:02:18 GMT, Ken Weitzel
wrote:



kip wrote:

Nothing holds the 169 in there only sticky dirt on the track..

Hi Kip...

Thanks! Naturally you're right.

Perhaps this is the first time this one's been out... sprayed
it with a little wd-40 just to wet it and it slowly but
surely jerked out... inch by inch. Tough part is keeping
it going straight.

Anyway, appears to be old dry sticky left over flux on
the edge of the board.. gonna gently sand it off in case
it needs to come out again.

Thanks again, and take care.

Ken

I am pretty sure it was that chassis...I worked on one once, and it
worked well when out of the tray, but not when inside. It turned out
that the tray was pushing a blob of solder on the edge of the board
down, causing a bridge.

Tom