[TechAssist] Magnavox FP5250 chassis PTV721 Manual SM7541

From: "Leonard G. Caillouet" <lcaillo@xxxxxxxxxxxx>
To: <techassist@xxxxxxxxxxxxx>
Date: Wed, 8 Jan 2003 17:36:50 -0500

Hope someone can help on this one.  I thought I had this manual but I don't.
I need a copy of the schematic of the small signal board if possible.  If
not I'd like to know the type of audio output IC that it uses (didn't check
it while I was there cause I was sure I had the manual).  Also need the list
of service mode settings, particularly relating to audio output.  Any
suggestions would be nice as well.

This one is an example of how things bite your butt.  Went out to diagnose
set with bad color, green halo, etc.  Found contaminated coolant as expected
and thought it would be an easy fix...picked up the CRT bulkhead and brought
it back to shop, cleaned CRTs, resealed, replaced collant and reinstalled
tubes.  Fired set up, tried to fire up then popped and quit.  Found HOT
shorted, pulled large signal board to shop, tested FBT and found it to be
bad.  I was leaving for a week so I sent it to Tri-State and had it rebuilt.
Reinstalled it and set works OK (aside from being a bitch to converge)
except no audio.

I wonder if when the FBT shorted it might have scrambled the EEPROM since
the convergence and several picture parameters were way off.  Variable line
level audio out works so I know the tuning and switching are OK, just no
output to the internal speakers nor external spkr jacks.  The set is working
and the customer uses an external system for sound much of the time but I
have to figure it out for him.

Thanks for any help.

Leonard G. Caillouet
Service Manager
Electronics World
Gainesville, FL
352-332-5608
352-332-5668 (fax)


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[TechAssist] Magnavox FP5250 chassis PTV721 Manual SM7541

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