Star Wars monitor (amplifone) faded to black

JC Arcade

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I know the title is not very descriptive. I just installed a new Amplifone tube in my Star Wars today (neck snapped on the old one :(). Did the convergence as best I could, and things seemed to look pretty good. I was playing for a bit tonight when the colors started to get darker and darker and then nothing. It's been pretty humid all weekend, so I don't know if that had anything to do with it. Any thoughts?
 
I don't think the focus went. It's a new flyback (Chad bulletproofed the boards for me awhile back).
 
Can you adjust the screen setting on the focus assembly and the pic will come back? Or is it just faded out and gone permanently?

Do you know if the following components have been replaced?:
VR1(7824), VR2(7924), Q3(BU406D),Q1(2N3904), Q2(MPS-U07)

Hopefully its not MC1, however I'm not sure I know how it would behave if MC1 was bad... it just is in the path of the HVT.

Also be sure to check the anode cup is secured properly... sometimes they feel like they are on right but only one of the legs is barely in the tube...
 
Also be sure to check the anode cup is secured properly... sometimes they feel like they are on right but only one of the legs is barely in the tube...

Yeah, I noticed this when putting it on. Wouldn't there be some kind of spark or arcing if the prongs weren't in, or would that only happen if the cup wasn't sealed?
 
Yeah, I noticed this when putting it on. Wouldn't there be some kind of spark or arcing if the prongs weren't in, or would that only happen if the cup wasn't sealed?

You may hear something but maybe not. It can look perfectly "sealed" but only have one leg in the hole.

I'm just assuming you have a drop in HV, either something driving the HVT or the HVT itself... doubt its the HVT since it has been replaced.
 
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I would bet the flyback crapped out. I had an original red that did the exact same thing. Usually when a fly goes bad it also takes out the BU406D Always use my philosophy "Man made bound to fail".
Start by ensuring you have proper voltages coming out of the deflection board. I believe ground on pin 7 and use red on pin 8 and 9. Next measure the voltages on the HV board. there's like 4 test points for +/- VDC. IIRC it's come where around +/-32VDC (check Amplifone FAQ to check my quoted voltages and pic will show you test spots.)
Also - if you don't have a HV probe you really should get one.
 
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Ya, new definitely doesn't mean 100% that it cannot be the issue.. Do you hear any static when you start the game up? If you run your fingers over the crt can you feel a static charge?
 
Well, a quick update of sorts. Just got home (long day at work) and turned the game on and it fired right up. Played a game, saw that there was a bit of neck glow, and went to get a drink. Went back down to the basement and the picture was dimming and then...black. Took a peek at the neck and there was no longer the little orange glow.

.
 
Check the 6.3 or so volts at the connection to the tube. If it's there, your problems lies in the the tube, If not follow it back to the problem...

mh
 
Check the 6.3 or so volts at the connection to the tube. If it's there, your problems lies in the the tube, If not follow it back to the problem...

What would be the problem with the tube? Please tell me not something like a crack. :(
 
I have been searching high and low and my search f00 just sucks today. You can do a quick dirty check on a tube by using a DMM on certain pins.

You could run it down to a local TV repair place and have them test it for you as well.
Have you checked the voltages on the boards as I previously mentioned?
 
I had KLOV'er Jetusenet come over with his HV probe and other equipment to see what was going on. Tube tested fine. Checked the wires and found that the focus wire on the HV board was hanging on by a thread, so that got fixed. But the biggest issue was/is the neck socket coming from the HV board. Jeff said the connection was WAY too loose on the tube neck. Did the best we could with it and with the focus wire fixed ,we fired it up. Voila! It was up and running again.

Still need to upgrade the socket if I can. Are there any other options besides cannibalizing one from an old, busted Amp HV board?
 
If you can get a hold of a dental pick, sometimes you can carefully re-arch those contacts for more tension.

The key is *carefully* because too much arch and they'll come out of the retainer slot, and then be crushed when you put the neck socket back on the tube.

Otherwise, you're stuck getting another socket off an old board. From what I've heard, finding those sockets is impossible and was the main hold up in reproducing a modern plug in replacement.
 
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