[TechAssist] Re: RCA PTK195B, mostly dead.

From: walter wood <wwood_38478@xxxxxxxxx>
To: techassist@xxxxxxxxxxxxx
Date: Fri, 30 Jul 2004 14:13:14 -0700 (PDT)
I had one of these kick my butt a couple years ago.
The dead set problem turned out to be on the
convergence board.
This can be checked by unplugging P/J19503. The set
will start up and run if this is the issue. 
The set will not be converged of course.
The data line on pin 20 of U19501 was being held
low.
The real problem was the glue under surface mount
caps C19503 and/or C19581.
Removing the caps, scraping the board and replacing
the caps fixed the set.
HTH
Walter
--- Kevin <kevintv@xxxxxxx> wrote:

> I already unplugged the keyboard and it is still
> dead most of the time.
> I did some more testing this morning and found
> that the eeprom (U13102)
> has only 3 volts on pins 8 (Vcc) and 5 (clock). 
> Pin 6 (data) has 0
> volts on it, instead of the normal 5 volts.  That
> certainly is not
> normal.  
> 
> Kevin Wilks
> Kevin's TV & Video Repair
> Penticton BC Canada
> kevintv@xxxxxxx 
>  
> 
> -----Original Message-----
> From: techassist-bounce@xxxxxxxxxxxxx
> [mailto:techassist-bounce@xxxxxxxxxxxxx] On
> Behalf Of tvservice
> Sent: Friday, July 30, 2004 6:34 AM
> To: techassist@xxxxxxxxxxxxx
> Subject: [TechAssist] Re: RCA PTK195B, mostly
> dead.
> 
> Unplug the front panel keyboard see if operates
> OK with remote.
> lift the 1K ohm resistor off micro to U14701 then
> plug in AC power you
> should now always have +5 and +12 out of U14701
> Set will not be on until press power,
> I have seen this IC intermittent
> also remove bottom tuner cover and carefully
> resolder every ground point
> and
> sm cap at ground points
> Remove glue from micro crystal and resolder
> If this set has dual tuners unplug cables to
> second tuner I have seen
> problems on the second tuner assembly cause
> intermittent dead set.
> hth
> Robert
> tvservice@xxxxxxxxxxxxx
> H & H Electronics Inc
> 
> ----- Original Message ----- 
> From: "Kevin" <kevintv@xxxxxxx>
> To: "TECH-ASSIST" <techassist@xxxxxxxxxxxxx>
> Sent: Friday, July 30, 2004 4:08 AM
> Subject: [TechAssist] RCA PTK195B, mostly dead.
> 
> 
> > This set works sometimes, but most times not. 
> When the set does work,
> > it will work for a minute and then just shuts
> off by itself and will
> not
> > come on.  I have the SM on CD rom and I am
> following the trouble
> > shooting procedure.  I found that when I
> monitor pin 19 of U13101
> > (microprocessor) and press the power button,
> pin 19 does not go high
> as
> > it is supposed to.  The micro has 5 volts going
> to pins 16, 29, 32 and
> > 51.  Pins 3 and 20 of U16201 are missing the
> required 7.5 volts.
> After
> > that the troubleshooting flowchart tells me to
> repair the defective
> P/S
> > source.  So I traced the missing voltage back
> to U14701, a dual
> voltage
> > regulator.  Pin 6 is missing 12 volts and pin 7
> is missing 5 volts.
> Pin
> > 1 and 2 both have 18-20 volts which is good. 
> Pins 3 and 5 are
> supposed
> > to have the 5 volts from pin 19 of the micro
> when the set is on.  But
> of
> > course there is no 5 volts coming from the
> micro.  The set must be
> going
> > into shutdown.  What can I check next?  Thanks.
> >
> > Kevin Wilks
> > Kevin's TV & Video Repair
> > Penticton BC Canada
> > kevintv@xxxxxxx
> >
> >
> >
> >
> >
>
------------------------------------------------------------------------
> --
> ---
> > Lost Password:
> > http://www.tech-assist.org  and select "Login
> Problems?".
> > Email Archives:
> > //www.freelists.org/archives/techassist/
> 
> 
> 
>
------------------------------------------------------------------------
> -----
> Lost Password:
> http://www.tech-assist.org  and select "Login
> Problems?".
> Email Archives:
> //www.freelists.org/archives/techassist/
> 
> 
>
-----------------------------------------------------------------------------
> Lost Password:
> http://www.tech-assist.org  and select "Login
> Problems?".
> Email Archives:
> //www.freelists.org/archives/techassist/
> 


=====
Walter Wood                  
Future Tech Home Center        
2786 Hwy. 43 N.
Lawrenceburg Tn. 38464
931-829-3337
Fax 931-829-4044
mailto:wwood_38478@xxxxxxxxx

-----------------------------------------------------------------------------
Lost Password:
http://www.tech-assist.org  and select "Login Problems?".
Email Archives:
//www.freelists.org/archives/techassist/
References:
- [TechAssist] Re: RCA PTK195B, mostly dead.
  - From: Kevin
[TechAssist] Re: RCA PTK195B, mostly dead.

Other related posts:
