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From: kip on 3 Apr 2006 14:12
Ok Tell us the original problem and what you have done so far.

"kip" <nospam(a)nospam.com> wrote in message
news:newscache$ktc5xi$oc6$1(a)newsfeed.niagara.com...
> Have you changed CR4118 ...try it.
>
> "Retro Depot" <retrodepot(a)bellnet.ca> wrote in message
> news:1WXXf.365$sh3.26223(a)news20.bellglobal.com...
>> First off, I'm new to this group, thanks for taking the time to read
>> this.
>> Now, this 35" RCA is driving me nuts and I'm questionning my ability
>> here. The problem this set has is as follows. With any input, (rf,
>> composite), the video is distorted, I mean, the image has what look like
>> 60 cycle hum bars, not moving, just there, couple of inches from top n
>> bottom. It'll lose vertical sync sometimes if channel is changed. Chroma
>> either disappears or is severely shifted. Skin tones go from normal to
>> almost flourescent green. Horizontal width is affected slightly on the
>> right, (1/4 - 1/2" black, slight pincushion, not enough to suspect pin
>> circuit though, probably due to this irritating problem.) The jungle has
>> been swapped as a result of the 'shotgun' approach suggested to me, I
>> have the schematic, it's not helping. Am I missing something very basic?
>> Please help.
>> Cheers, Steve
>>
>
>


From: Retro Depot on 3 Apr 2006 19:11
Whoa... I've got to print this, I mean what JURB wrote. I'm liking the
thought that maybe the vertical section might have some issues vise-a-vis
electrolytics, but you see, I've lifted every last one and found no smoking
gun. I've had this type of problem with video signal on other chassis,
different brand, (1vp-p), corrupted the sync and color info after the burst,
(visible on scope), turned out to be bad cap near a coil, go figure. Now
back to this beast, I will try swapping out that zener tomorrow and look for
more. I've tried replacing the CR4118, just in case, still no dice. Might
have been poor regulation on one of the other supply lines, both 9 & 12 volt
supplies scoped no noise and bang on voltages under both stby & run
conditions. It's a little decieving when a good strong signal is used, other
than the picture going to b&w when scenes change, then go back to color for
the next scene, it has only the 'shifted left' symptom and the intermittant
hue shift, suttle, but still there. There's that banding, banding with
vertical linearity affected just within that band of distorted, almost like
flagging effect seen with mis-aligned vcr's, from time to time along with
severe hue shifts and a noticeable gap on the right, slightly bowed in. Hope
this info is useful, will keep everyone posted with results.
Cheers, Steve


From: Jason D. on 3 Apr 2006 23:05
>Unfortunately without in depth study of the original training manual,
>and precise data on the jungle IC, part of this is guesswork at best.
>All we can do is try to make good guesses.

I have tried to get training books on 169 and even we sent payment to
Thomson 2 years ago so I can get the service manual for DTV version
and training book on it. Not gotten the books and yet we get many CDs
from Thomson still.

I would still want to get them.

>Every once in a while this direct view 169 would come on with no audio
>and the menus shifted, IIRC to the left. IIRC the usual problem is that
>they're shifted to the right. Everybody in the county I think worked on
>it, turned out to be the 503Khz crystal off the jungle IC. Why ?
>
>This was one of those sets...."this is your job muth______". It was
>very important and they gave me all day at $23 an hour which is rare. I
>had to do it. How did that part cause that symptom ?
>
>Oh, originally it came in for a blown HOT, but the .056/400V was fine,
>geometry was fine, except once in a while this symptom would occur.
>
>If you study the print of the 169 you will see that the EPROM is not
>initialized when you plug it in, that doesn't happen until power on.
>The 503K rock drives the countdown chain, which is needed for H sweep.
>The EPROM runs off of H sweep. What was happening is that sometimes the
>oscillator didn't start immediately, and the data from the EPROM to the
>micro came too late. A 169 will run without an EPROM, but it's in some
>type of "fallback" mode or something.

Blink, What what??? I thought micro did the job with eeprom not the
503KHz? EVEN the micro did have own crystral!? That why ingorance is
showing! Even I have worked on 169 often, this why I needed the
training book.

>You think you got it bad ? (well you do on this one somewhat) I have
>had to adjust vertical height to fix a greyscale proplem. That was a
>Sony, at least you don't have one of those.
>
>JURB

I think we have still or had tossed a RCA low end version of 169 27"
that intermittently vertical collapse into a "small horizontal
sinewave". I resoldered, changed zeners, diodes, changed few parts,
checked everything, kept collapsing intermittently. Whack and it's ok
or turn off then back on will fix it. When working, fault doesn't
show up with whacking, just let it run for one hour, 3 hours, even
week or weeks, bam, collapsed.

By the way, I rescued 20" CTC168, same chassis as 169. Waiting to be
clean up of hardened up dust coatings & replace rusted stuff, circuit
board itself with components is in excellent condition. I have tons
and tons of CTC169 to recycle parts from.

Cheers, Wizard

From: Retro Depot on 4 Apr 2006 00:03
Man, my boneyard is peppered with 169's, hardly any 177's thru 203's and
beyond. Now for some sad poetry!

I must take solice in knowing that some of you share this plight, alas, I
feel part of a brotherhood, a fraternity of sorts. I shall no longer bow
this head in shame, for I know of a grouping of like minded souls who reap
not what hath sewn by thine own hands, yet cultivates this agony of
technical woe... oh woe...oh woe.... .

Sorry 'bout that, it just felt right ;-), talk to you seriously tomorrow.
Cheers, Steve


From: Leonard Caillouet on 4 Apr 2006 06:38
Have you looked for chocolate syrup on the boards? No kidding, the brown
rubber spacers melt into a goo that causes havoc in some of these.

Leonard

"Steve" <retrodepot(a)bellnet.ca> wrote in message
news:OOaYf.53210$6Q2.481891(a)weber.videotron.net...
> BinDair DunDat! No Change.
> Cheers, Steve
>
>


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