Star Wars Upright Amplifone Help Needed

These are all great suggestions.

So far, I have previously measured the neck pins for both continuity and ohms. Continuity is present, and about 1.5 ohms there. I wired the 6v AC from the power supply near the transformer directly to the WHT HTR connection on the HV board. I tested for 6v at the WHT HTR solder point on the board, and it's there. I've also tested from continuity from the HV board heater wires to the yolk, and it checks out there. I've even opened up the yolk and tested for continuity inside - all good. I've looked at the neck in near darkness, and can't find a single glow in it.

Also, when I went through the discharge procedure, there was no pop, no sizzle, nothing. The anode came right out of the tube with a simple twist of the screwdriver.

The current flyback is not providing the 6v, but tests good with continuity throughout. It seems to be that the backwards installed capacitor may have destroyed the flyback due to its proximity to the capacitor.

I just can't figure out why there's no neck glow when the 6v AC is applied to it. It would seem to be a completely separate issue from the 19.5k HV going through the anode to the tube. I haven't bought the new flyback yet, but I'm getting closer and closer to suspecting it as the culprit. If the voltages are there at the bottom (24v), there's no reason for it not to wind up the 19.5k.

I'm still resolved to get it going, just scratching my head a bit at this point. I should at least have neck glow.
 
Uh, wait a minute... I tested for continuity AFTER the resistor, not before it. Good call! Man, I do some dumb stuff sometimes.

Sure enough, no continuity. I'll check my bin of resistors to see if I can find a suitable replacement and will solder it all back in and fire it up.

By the way, does everyone else agree that the resistor is brown, grey, silver and gold, meaning 0.18 ohms @ +/- 5%?

Thanks!

omegaman said:
Needs 6v AC, check the resistor that is inline with the white wire, its a very simple setup ....it can only be an open circuit resistor stopping it from kicking out the correct voltage. You can hook up a car 12v lamp across it for testing, should see it glow.

Without the heater lit you won't have a picture......you're nearly there now :)
Click to expand...
 
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Yeah, trying to be absolutely sure about this resistor being the right one. Looks like a 1/2 watt, but the 0.18 ohm thing is throwing me a bit.

Here's the picture of the resistor:

attachment.php


Please take a look at it and make sure you agree on the color labels. I wanna get this thing right.

Thanks!
 
It's Working!!! Well, sort of.

I finally found out why I didn't have the neck glow. One of the brown heater wires had broken loose from the HV board due to a bad solder connection. Fixed it up, soldered the flyback to the game, turned it on, and...

... signs of life! However, here's what I ended up with:



Basically, what you see here is that only the top half of the screen has a picture, and it's the attract mode showing. There's nothing on the bottom half. There's also a highly concentrated beam in the center of the screen in a circle. There's also no great deal of color here, and the focus is out of whack (will fix/adjust later).

I should also mention that I've already rebuilt the deflection PCB with the Arcadeshop cap/transistor kit. I'll be rebuilding the ARII power supply while I wait eagerly for the next post to get this thing going.

I'm thrilled at this point to just see the first real signs of life in this thing. What's the next step to take? I'm soooooo looking forward to blowing up some Death Stars!

Thanks,
Blaine
 
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Getting there, don't run it for too long like that, you will burn the screen. Looks like you have another wire off somewhere causing the grid bias to be out....that or the focus wire has come off.
The half screen issue is down to the deflection board....you know that though :)

I guess you could have the HV turned up way too high...have you got a HV probe?
 
Looks like a deflection issue, mine had that exact problem when I bought it.

I had a known working deflection board (From M_McGovern ;) ) and that fixed it.

Maybe, double check you used the right deflection transistors etc.
 
Two out of three ain't bad...

Almost there! Almost there!

But I don't quite have the "It's Away!". I'm still just impacting on the surface. (Nice references, eh?)

OK, so I rebuilt the ARII with the Arcadeshop rebuilt kit. I also removed the main board set and cleaned the edge connectors with an eraser and iso alcohol.

In the mean time, I also had to repair a broken focus pin on the neck. That is no fun. I did come up with a temporary (probably permanent) solution by attaching a wire to the pin stump and soldering the other end to the focus control on the flyback.

I fired it back up, and I got this:



It's in red and blue, but no green, so I know I've at least got to figure out why the green ain't working. I also made some adjustments to the brightness and focus, and the image cleared up quite a bit and reduced the intensity of the bright spot in the center.

Also, at some point, the game decided to start doing the 1/2 half screen again. The top shows the picture, the bottom does not.

Big progress here though. I can at least see it now, and I know the flyback is good.

What are the last steps to get the green going and to make sure the screen shows both halves? Sounds like deflection board stuff, but where on the board?

Thanks everyone. You've all been very kind to keep helping me, and I'm swelling with pride every time we make progress with this.

Blaine
 
Yes yes!

Turn that brightness down- WAY DOWN- Once you burn off the phosphor in the center of the screen, there's no putting it back. You can still play like that and it may not be to noticeable at times, but other times it WILL.

Many things could be contributing to the missing half image. There could be broken traces on part of the deflection board. Wiggle around some of the pots while the game is on- you can even prod the transistors a little.

With a voltmeter (ohmmeter), and the game OFF, you can test the base-emitter and collector-emitter junctions on some of the deflection transistors. Some meters have a diode setting and you should see a .4V or so drop across the base-emitter with the leads in one direction and an open circuit the other direction.

See if there's a ground or something missing from the tube to the neck board. That brightness SCARES me.

Good job so far.

Kerry
 
You are so lucky repairing that neck pin. Are you talking about the tube?

Wow, I lost a 25" Amplifone tube that way, the gas leaked out

Looks to me like all the pots are out of wack

Do you have a HV probe to measure HV?

:)
 
Progress!

Ok, I feel quite confident that all three colors are being sent to the tube and are being displayed. If I can read text, see scores and see TIEs and the trench, all three colors are there.

The 1/2 screen issue was due to poor solder points at the J105 pins. Funny thing (not really) is that I reflowed them when I rebuilt the board. Another lesson learned (remembered): use the damn magnifying glass when reflowing pins.

Weird though - the #2 and #3 pins show continuity with my DMM, as do any components as they branch away from these pins. I've checked and checked and checked the solder pads for bridged connections, but nothing there. The schematic shows that the #1 and #2 pins go to Y and the #3 and #5 pins go to X. BUT... it doesn't show that they are interconnected anywhere. I don't have anything at J105 bridged, and I can't find anything bridged along the parts (top) side of the board. Should the X and Y (#2 and #3 pins) have this continuity together?

So, I actually played through level one and also put the game in test. Everything is working as expected, but still have the screwed up looking picture. Here's where I'm at now:



So I think the big ass bright spot in the near middle of the picture may be the last issue to knock out. IMPORTANT NOTE: I removed the connector from J105, and the bright spot remained. It doesn't seem like it can be a deflection issue if it exists when J105 is disconnected and there's no chatter.

Oh yeah - as much as I would like to own one, I don't have a HV probe. I'll either have to set the HV from the B+ or make gentle adjustments until it's right. That is, unless there's a cheap way to get one. The Fluke probe is $180, and I ain't dumping that kind of money into a one-time use item.

Thanks everyone! Almost there!
 
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Jees, I hope you didn't burn a hole in the phosphor having it run SO bright for SO long !!!

Whenever you see a bright center spot like that either turn brightness WAAAAAYYY down until you can JUST see the spot OR TURN OFF and do either right away !
 
The high voltage is probably OK.

All those retrace lines are burning my eyes- Is your Xwing fighter heading for the Death Star or the center of the SUN?

GOOD GOD HAVE MERCY

Turn it DOWN-

Does the brightness pot have ANY effect? Is that one or the other resistor in the circuit shorted? You may actually be able to measure that G2 voltage with a cheap voltmeter. It may be out of range though-

Kerry
 
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