[TechAssist] Re: RCA, G27304DT, CTC177AM2, Tuner problem UPDATE

  • From: "Connie Dravenstott" <cdravens@xxxxxxxxxx>
  • To: <techassist@xxxxxxxxxxxxx>
  • Date: Wed, 13 Oct 2004 23:22:56 -0400

Daryl,
I had one of  these drove me nuts also.  Mine had an intermittent coil
outside of the tuner shield.  I don't know if your version has it but it may
be worth a shot.
Another one had a low B+ line into tuner which turned out to be a resistor
had changed value. Sometimes you just got to go back to the beginning and
start over.

Bill Dravenstott
Elza's Home Store LTD
Ashland, OH
----- Original Message ----- 
From: "Intrepid Video Support" <support@xxxxxxxxxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Sent: Tuesday, October 12, 2004 10:18 PM
Subject: [TechAssist] Re: RCA, G27304DT, CTC177AM2, Tuner problem UPDATE


> Daryl,
> All I can recommend is remove all the solder from the grounds. Get
yourself a head-visor magnifier and
> look carefully at the tuner area.
> As many of these as I have done, I still can find a way to make a solder
joint or lift a trace.
> If all looks OK, resolder.
> Now, moving those coils around was not a wise choice.
> Good luck.
>
> Jeff
> --
> Intrepid Video TV/VCR Repair
> 263 S Front St, Steelton PA 17113
> 717-939-7708; (F) 717-564-4952
> www.intrepid-video.com  www.tech-repair.net
> ----- Original Message ----- 
> From: <daryls_tv@xxxxxxx>
> To: <techassist@xxxxxxxxxxxxx>
> Sent: Monday, October 11, 2004 11:52 PM
> Subject: [TechAssist] Re: RCA, G27304DT, CTC177AM2, Tuner problem UPDATE
>
>
> Another day shot to Hell.....
> I spent all day again on this dog.
> It was mentioned several times to replace U7301.  This was the first part
I replaced to no avail.  I
> didn't have another new one to try but I had the next best thing.  I had a
working set to borrow parts
> from.  I replaced the IC again but still no change.  Thanks to Barry
Thompson for the flow chart.  I
> followed it out and found nothing wrong.  I compared voltages to the
working set and didn't find anything
> out of line.  I swapped out the varactor diodes without any help as well.
I figured I couldn't mess it up
> any more than what it was... so I played around with the coils and
parameters.  Now I have some small
> gains but still not acceptable.  Channel 2 has lines and motor boating.
Ch. 3 through 6 is acceptable but
> not great.  Ch. 7 through 10 is good.  Ch.11 has no picture and sound,
just lines.  Ch. 12 through 18 are
> good.  Ch. 19 trough 22 are ugly with lines.  Ch. 23 through 39 are great.
Ch. 40 through 48 has poor
> picture with lines and has noise in the sound.  Ch. 49
>   & 50 has nothing but motor boating. Ch. 51 up is great until Ch. 99
which has lines and a poor picture.
> That is the highest channel on the cable system.
> I can still place my finger near some of the coils in the tuner and it
will perk right up.
> Any other ideas would be appreciated.
> Thanks,
> Daryl
> Daryl's TV
> 2402 Wyoming Ave.
> El Paso, TX  79903
> 915-565-9184 Voice/Fax
> daryls_tv@xxxxxxx
> www.angelfire.com/tv2/daryls_tv
>
> ----- Original Message -----
> From: daryls_tv@xxxxxxx
> Date: Sun, 10 Oct 2004 12:42:56 -0600
> To: TechAssist@xxxxxxxxxxxxx
> Subject: [TechAssist] RCA, G27304DT, CTC177AM2, Tuner problem
>
> >
> > Hi,
> > This RCA, model # G27304DT, ch. CTC177AM2, is really kicking my behind.
> > It started with the complaint from the customer of losing some channels
with lines in the picture.  I
> pulled it into the shop and did the usual tuner re-soldering job.  Set
looked great and was delivered only
> to find out it was doing the same thing.  Took it back to the shop where
it worked great.  I re-soldered
> everything again plus all of the connections on the smds.  Delivered it
again and you guessed it...same
> thing.
> > The channels from 40 through 50 were either missing or full of lines or
motor boating.  I played with
> some of the tuner parameters and it seemed to work but not to my
satisfaction.  The customer was pleased,
> so I left.  A week later, same thing.
> > I pulled it back to the shop where it worked fine.  BTW... the customer
has another set that works fine
> on the same cable line.  I put an attenuator on my cable line and the
trouble showed up and even worse.
> It gave me channels 2-6, 18-22, and 40-50 with the problems.  I
re-soldered every smd in the video section
> besides the tuner again and all of the grounds in the set... no help.
Looked with a high power magnifier
> for cracks in the print (none found).  Replaced IC7301, C7414(cracked),
CR7102(didn't check the same as
> the others), Q7102(RF amp), U3201(eeprom), & U1001(t-chip).  Did the tuner
alignments after each parts
> change but still no joy.  I found that if I would place my finger over
coils L7114 & L7112, the set would
> start to function properly.  I got the same effect placing my finger over
L7115, L7113 & L7111.  I didn't
> have to touch the coils, just put my finger near the coils.  This symptom
reminds me of the old tube days
> when the grid neutralizer trimmer cap was
>   o
> >  ut of adjustment on the RF amp tube.
> > I really hope someone has encountered this and has a cure.... Help!!
> > Sorry for the long post but I deemed it necessary to explain the
problem.
> > Thanks,
> > Daryl
> > Daryl's TV
>
>
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