1981 Magnavox with a problem.

[Firebird]

I have a 1981 Magnavox tv. Model number RA5054. It has a t815-09 chassis. It has not worked for a while but somehow i have convinced my mother not to throw it away. I was there when she bought it in january 1981. It has stereo speakers and separate 10watt amps to simulate stereo. It gave a little trouble when it was new, the crt module was replaced and an ic was replaced on the power module. When you turn it on the channel number displays, no picture, no sound, The picture tube gun lights but after 20 or so seconds the reset button kicks out. After reading some of your post i ordered a horizontal output transistor, installed and resoldered pins on the retrace module. It still does the same thing. I have had some repair training but would like the advice of an expert.

[radiotvnut]

Check the 4-lead safety cap on the retrace module. They were known to short. If it's bad, you'll probably have to replace it with a current production "orange drop" cap because I don't think anyone makes the original 4-lead cap. Those 4-lead capacitors were not reliable, anyway. They would either short or blow open. If they open and the internal interlocking feature of the cap does not open, the HV will skyrocket and blow the neck off the CRT.

[Firebird]

I am a little new to this, What is a orange drop cap?

[Firebird]

I checked the safety cap and it is leaking so it is bad. The part number is 250663-18, also it says 648 at the top of the label. What rating cap do i replace it with. Also what is the best way to connect since there are four wires and only two on the cap?

[Eric H]

Hi Firebird, welcome to VK.

I moved your posts to it own thread here in the Rectangular & SS Forum, it'll have a better chance of being seen and getting help than if it's attached to another unrelated thread.

[kx250rider]

I agree on that safety cap.. Replace first, and then if the set still kicks the circuit breaker out, you may have a bad HV tripler (the gray box with the anode lead from it, up to the top of the CRT). Those leaked a lot, and caused a heavy load on the power supply. Easy to verify; carefully unsolder and secure AWAY from any metal, the black wire from the tripler going to the flyback. Turn the set on, and see if it still shuts off. If not, the tripler is bad. But again, watch out for that black wire while you have it off the terminal. The RF can arc an inch or more, and will cause damage to other parts, or of course cauterize a hole in your finger ;-). Also, when you resolder that wire, use black silicone RTV sealant to cover it with a blob, so as to protect it from arcing later.

Charles

[legenbass77]

I also have the same question as Firebird with my 1977 T-995 chassis regarding replacing the 4 lead safety cap with a 2 lead orange drop cap on the retrace module. Do I just bridge the solder pads, or re-route the 2 leads a certain way? Schematic shows each lead goes to separate pins on one module socket. Pins 8,9,11,12 with a silicon diode across pins 8, and 12. I'm wanting to replace the 4 lead cap on my set for increased reliability after reading how they can fail, and destroy the crt. As far as I know it is the original one, and being 35 years old it could go bad any minute. Mine shows part 250563-11 which cross references to a .0086 mfd @1600 volts. The 250563-18 cross references to a .0135 mfd @1600 volts.

[radiotvnut]

Yes, bridge the end terminals together. I had a T809 19" with a shorted 4-lead safety cap and I had to connect two HV orange drop caps in parallel to get the correct value. I removed the old cap from the chassis, bridged both sets of end terminals together on the chassis, installed the orange drop cap, and the set worked great.

When checking these caps, you will read a short circuit between each set of end terminals. There should be no short when measured from end to end. If it reads shorted or shows any resistance from end to end, it's bad and should be replaced.

[Firebird]

Put in the capacitor. Set came on and stayed on. Still no picture. Where do i find a tripler? I have not been able to find one so far.

[bgadow]

Are you looking for the tripler in the set...or are you looking to buy one? One of us might have a spare; I have a box of assorted triplers.

[Firebird]

I am looking to buy one.

[Firebird]

Do you have one for the T815-09 chassis?

[Firebird]

Does anybody know where i can get one?

[radiotvnut]

Do you know for sure that the tripler is bad? If you feel static on the screen when you turn on the set; then, you are getting HV and the tripler is likely OK. If no HV is at the CRT; then, unsolder the input lead to the tripler and if there is HV coming out of the flyback, the tripler is bad. If you have no HV coming out of the flyback, you have a problem in either the horizontal output, horizontal driver, or horizontal oscillator stages.

[Firebird]

I have HV. Put in new horizontal output transistor. What do i look at next?