NAP must have used some excellent CRT's in their sets

[radiotvnut]

When I say NAP, I mean the Magnavox, Philco, and Sylvania brands of the '80's and '90's.

Today, someone gave me a '92 BPC 19" Magnavox stereo TV with A/V input jacks. It was dead and removing the back revealed a very nasty chassis, with 12 pounds of dirt hanging off the HV lead and nicotine all over the insides. I could also tell that the PC board had been very hot and there were many heat related loose solder connections in the set. That tells me that this TV has about 20 billion hours on it. This is the chassis that has the 100uf,200V cap, located behind the flyback, that always fails. This one was no exception and it took out the HOT, the TIP47 transistor in the regulator circuit, and the B+ fuse. Also, for some reason, one of the side plastic chassis mounting rails was missing. Replacing those parts (from junk boards) still didn't power up the set and there's a chance that the STR30130, which I don't have, may be bad and I seem to remember a small resistor and some other transistors in the power supply that would fry; but, since it's such a high hours set and knowing that no one would buy it even if I fixed it, I've decided not to go any further on repairing it.

Just for kicks, I decided to test the CRT on my B&K 470. Despite the high hours, the CRT still checks well into the "GOOD" area.

I actually have a little newer, and cleaner, Magnavox that was a victim of a fall and sustained damage to the shadowmask. Otherwise, the set works fine. I think I'll use the tube out of the nasty set in order to fix the better looking one.

Come to think of it, out of all the NAP sets that I've fixed, I don't recall seeing too many with an unusable CRT. I've seen a few weak ones that would come back after a light jolt. Most of these tubes have the EIA code for Sylvania on them and I think I remember reading somewhere that the main reason NAP wanted Sylvania was for it's CRT plant.

I'm certainly not complaining about the TV. It lived a hard life for 19 years and could probably be made to live a few more years if I wanted to go to the trouble of finding out what's wrong with it. Let's see if these new flat screen TV's can hold up as well.