[TechAssist] fix: Hitachi Ultravision 46UX24B loses sound after warm]

My response to Alvie below:
(Thanks, Bob).
As usual, Alvie you are always so gratious to help, as you have in the
past.
I wanted to share the fix.
I listened carefully when the sound went out. I realised the "buzz" that
remained was the 4.5 MHz sound carrier. Ahh, "IF"... The main tuner
"U101" is an
integrated Sony tuner with audio and video IF processing internally.
I happened to have a tuner and swapped it out. The set even has a better
video
display now,(it seemed to have a silver effect to the bright areas
before) and
sound is clear, and has been on for an hour OK. Looks like U101 was the
fix.
Inside Tuner U101 is an:
IC02: SBX1838-01 (Sony IC,looks  like a large version of a SBX1637, has
10 smd
caps) ,
IC01:(Sony IC) CXA1446S
Trace side:
two SMD ICs:
numbers: DA5633  (Philips) and 4092FP (Mitsubishi)
ceramic filters: SWF01, SWF02.
Not sure the culprit. any guesses?
Thanks, all, for the assistance.
A true Thanksgiving week.
Phil Bader

"Alvie Rodgers C.E.T." wrote:

> Hey Phil:
> I don't have much on this symptom:
> Here's some:
>
> Symptom: NO AUDIO. MUTE ACTIVATED. NOTE: C461 IS LABELED K464 ON THE PWB.
> Cause: C461 SHORTING ACROSS R426 or K467. CAPACITOR IS BENT TO THE LEFT.
> BEND THE CAPACITOR TO THE RIGHT, AS VIEW FROM THE BACK. LOCATION: JUST
> BEHING THE REAR JACK PANEL PLASTIC, JUST IN FRONT OF THE 8 TUNER. NOTE: C461
> IS LABELED K464 ON THE PWB
>
> Symptom: LOW AUDIO
> Cause: REPLACE IZ01
>
> Do you have any activity on pin 48 of the Microprocessor?
> Do you have any activity on Emitter of the Q013?
> Do you have any activity on Base of the Q403?
> What's the DC potential of pin 11 of I401 with and without Audio?
>
> **********************
> Alvie Rodgers C.E.T.
> Technical Writer/Trainer
> Hitachi Home Electronics
> www.hitachiserviceusa.com
>
> Please post your repair for others
> to benefit.
> **********************
>
> ----- Original Message -----
> From: "Gemini Computer & TV" <geminitv@xxxxxxxxxxxxxxxx>
> To: "Alvie Rodgers C. E. T." <rodgers@xxxxxxxxx>; <tjanphyl@xxxxxxxxxxxxxxx>
> Sent: Monday, November 24, 2003 6:56 PM
> Subject: Hitachi Ultravision 46UX24B loses sound after warm
>
> Phil,
> I have forwarded this to Alvie Rodgers from Hitachi for his advice and
> expertise.
>
> Bob Waterman, CET® #RI-28
> Master Technician License #9109
> Service Manager / Parts Manager
> Gemini Computer, TV, & Security Alarms
> (508)695-7302
> (508)695-7769 FAX
> geminitv@xxxxxxxxxxxxxxxx
> geminitv@xxxxxxx
> www.geminicomputertvsecurityalarms.com
>
> ----- Original Message -----
> From: "Philip Bader" <tjanphyl@xxxxxxxxxxxxxxx>
> To: <techassist@xxxxxxxxxxxxx>
> Sent: Monday, November 24, 2003 2:44 PM
> Subject: [TechAssist] Hitachi Ultravision 46UX24B loses sound after warm.
>
> > Came in with sound working.After 10-20 min I noticed no audio. Turning
> > up volume I hear a low buzz ( like a mic with bad ground).
> > Has a jack panel with Sony ICs.Cool sprayed aropund, no effect so far.
> > Any histories on this?
> > I'm downloading the pdf on it, but going slow today.
> > Of course this was dropped off just before close Saturday, she called
> > this morning for a "status"...
> > Thanks,
> > Phil
> > --
> > Philip Bader
> > Jan Phyl TV Inc. (estab. 1976)
> > 3420 Recker Hwy. Winter Haven, Fl. 33880
> > Fax (863) 299-8821
> > email: tjanphyl@xxxxxxxxxxxxxxx
> >
> >
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> >

--
Philip Bader
Jan Phyl TV Inc
3420 Recker Hwy
Winter Haven, Fl. 33880
Fax: 863-299-8821
"consumer electronics service since 1977"

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