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Old 01-05-2017, 06:47 PM
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Found this on the side of I-840 today, Magnavox console tv.

Hi all! on the way home i saw this sitting on the side of the interstate. It doesn't look dropped or scarred up. It is a Magnavox 25C549 chassis, made in Greeneville TN, USA Jan of 1986. i powered it up but doesn't come on, i hear a faint buzzing sound from the chassis, anyone have a schematic for this set?
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  #2  
Old 01-05-2017, 08:59 PM
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Originally Posted by mr_fixer View Post
Hi all! on the way home i saw this sitting on the side of the interstate. It doesn't look dropped or scarred up. It is a Magnavox 25C549 chassis, made in Greeneville TN, USA Jan of 1986. i powered it up but doesn't come on, i hear a faint buzzing sound from the chassis, anyone have a schematic for this set?
Lemme check - I may have the NAP manual - have 5 or 6 binders full of NAP stuff. I'll check tomorrow, before the snow dump we have coming. I also have service tips for the set as well - most are NAP sourced...
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Last edited by Findm-Keepm; 09-29-2017 at 06:39 PM.
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Old 01-05-2017, 11:20 PM
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Nice catch! Unusual place for a console TV to get dumped, even more unusual that it's not beat up, or that it even survived.
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Old 01-06-2017, 06:58 AM
kf4rca kf4rca is offline
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Somebody running low on gas must have decided to lighten their load. Finders keepers, losers weepers!
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Old 01-06-2017, 07:28 AM
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I've got the service lit - most of it. I have the model specific data and the supplement with schematic, parts list, breakdown list and interchangeability data. I also have the Switchmode power Supply manual (theory, general operation, a must for the "bitch mode" supplies these have...) from NAP, all yours for postage. PM me your address, and I'll get it out to you.

In the meantime, do you have 130V across the diode (D404) on the yoke? Negative lead to the anode (hot ground...)That was always our starting point - D404 is a high-failure item in these chassis, and my earlier attachment provides a list of stuff to check as well - lots of bad solder jobs on the early runs of these chassis - the 25C55X series didn't seem to have the solder issues, just the earlier 25C53X and 25C54X stuff.

January 1986....when the Challenger tragedy struck.....
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Last edited by Findm-Keepm; 01-06-2017 at 07:43 AM.
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Old 01-06-2017, 08:47 AM
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I too cannot let such a good example like that just sit. I always find them a home. Hats off to you!

I worked for a dealer then and remember that as the mid-level set. A one knob-tuned with UHF presets was the entry level.
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Old 01-06-2017, 09:55 AM
dieseljeep dieseljeep is offline
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Originally Posted by Findm-Keepm View Post
Lemme check - I may have the NAP manual - have 5 or 6 binders full of NAP stuff. I'll check tomorrow, before the snow dump we have coming. I also have service tips for the set as well - most are NAP sourced...
We had a considerable amount of snow, a lot of it melted in the unseasonable warm weather, but now we're paying for it. Zero or colder, with sub-zero wind chills. The snow is just an inconvienience, but that extreme cold.
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Old 01-06-2017, 10:58 AM
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The snow is just an inconvienience, but that extreme cold.
I agree 100% ! We need a few days below freezing to kill the mosquito eggs and other pesky bugs, but please nothing near, at or below zero.....
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Old 01-06-2017, 11:06 AM
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Originally Posted by dieseljeep View Post
We had a considerable amount of snow, a lot of it melted in the unseasonable warm weather, but now we're paying for it. Zero or colder, with sub-zero wind chills. The snow is just an inconvienience, but that extreme cold.
Yeah, the snow is only an inconvenience at worst... It can be useful too. Folks at work are afraid to park in the half plowed spaces...I don't like(/worry about) my GMC much so I just run over the snow hills and park on them. Seems as soon as I do someone else will get the stones to park there after I leave for lunch.
The cold REALLY stinks! The heater in that GMC ain't worth a damn under 20 degrees...It barely can get the car above freezing once it hits zero...engine runs real cold too. If I had better winter clothes I'd try taping card board over the grille to see if impeding cooling helps.
Saw something unusual on the way to work today...I guess it would be called a 'snowbow' since it is WAY too cold for rain...Did not know such a thing could form in weather this cold.
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Old 01-06-2017, 01:14 PM
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The cold REALLY stinks! The heater in that GMC ain't worth a damn under 20 degrees...It barely can get the car above freezing once it hits zero...engine runs real cold too. If I had better winter clothes I'd try taping card board over the grille to see if impeding cooling helps.
Thermostat stuck open, perhaps?

jr
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Old 01-06-2017, 02:16 PM
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Seems almost everyone starts hating the cold and snow upon growing up. I'm one of VERY few adults (well, chronologically anyway) who like winter. We've hardly had any snow since winter began but we're finally getting it today, and I'm thankful for it. The night I pushed the Heathkit console home it was 10 below, making the activity that much more comfortable.
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Old 01-06-2017, 03:37 PM
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I remember the C5 chassis very well. It seems like they only had two types of service issues: either they were a quick and easy fix, or they sat on the bench for days while every tech in the shop pulled his hair out trying to troubleshoot it.
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Old 01-06-2017, 06:04 PM
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Thermostat stuck open, perhaps?

jr
Or missing.....had that on a Nissan Truck I troubleshot for a friend - A/C use would overheat the engine, so the dealership removed the thermostat. Come cold weather, he froze his hiney. Installed an OEM and no more problems, and gas mileage went up considerably......
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Old 01-06-2017, 06:24 PM
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Thermostat stuck open, perhaps?

jr
My old volvo had that problem, the thermostat failed in the open position. worked great in the summer froze till i figured it out. oh i'm thinking the H.O.T transistor has failed I tested it with my Leader in circuit tester and and it said dead. I let the power stay on for about 30 seconds and the heat sink is warm. In findem keepem's post with the helpfull hints it said the trans is a 2sd1398(8)?
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  #15  
Old 01-06-2017, 07:02 PM
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Thermostat stuck open, perhaps?

jr
Thanks for the tip! I'll have to check into that. Symptoms match what I've read. Replacement thermostats claim 192 degrees F is the factory open point, if the temp gauge is accurate I'm not making 150 F in 30 min of operation...IIRC the check engine code I have was traced to timing and cooling system...Time to find that sheet, and order a new thermostat.
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