amplifone vector time

Tr3vor42532

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Hi, I just picked up a star wars, this is the first amplifone I have my hands on so this is new territory for me. Did the very minimal to get it going, replaced the 2n3055 and verified voltages, tested drop across the harness and filter pcb, all that looking good. plays blind, hooked up a scope, no x or y, so I borrowed the AVG from my space duel and that fixed that issue. Since the thing had been powered on the past week so the seller could post a video of it playing blind and while I was there to pick it up, I figured I had nothing to lose to flip the switch on the monitor, whatever damage that was going to be done was probably already done. Checked fuses, connectors all that good stuff and fired it up. I did get a picture, but it was dim. considering the condition of the game's connectors and the fact that the AR2 isn't roasted or hasn't even been removed before today, it's probably not high hour. double checked tube health with my tester and it's all happy, so it's definitely a chassis issue. I'm gonna assume Red is not dead until it proves me otherwise. Glued the small gear together for the Y axis of the yoke controller and ran it through a death star explosion or two night driver mode for shits and giggles. So yeah, someone's home but not quite all the way.

I figure I'll get the basic maintenance stuff done before I go any further because the HV board's caps are probably roasted to hell and back by those resistors. Read up on the FAQ to order me some parts and whatnot. I noticed that the BU406D is not a BU406D, but a BU409. there's also a big diode tacked onto the backside of it. I saw in the faq that there are people who have had luck adding an external diode for damping, I'm guessing this is what it looks like? either way I'm gonna get the right part and be done with that.

20250414_032212[2].jpg

Anyway besides that I just have three questions for now.
1: do the crt sockets ever go bad on these? not a real big fan of how it looks like the thing is trying to come apart, but maybe that's normal.

2: what's the best fpga AVG replacement available now? I see that there are a few options. I remember trying the fpga avg in my gravitar on my space duel and it really didn't like it. I'm guessing not all of them are created equal?

3: what's a good thing to do with those big fat power resistors that are burning a hole through my pcb. I'm thinking a fan, but not sure if there's a more preferred way to do things

I guess if I have any other questions after this I'll post them here later.

Thanks.
 
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That's some pretty terrible solder rework. I see several cold joints and most of the others are questionable. You should reflow them all remove all of the old solder and resolder those joints while you have it on the bench to undo the mods.

For the power resistors...I can't see them so I don't know which ones, but typically you should mount them high off the board. Keep at least 1/2" of free space between the resistor body and the PCB. And other components. Don't let them cook your caps! For bigger heaters, use bigger spaces. A fan shouldn't be required but it can help as long as it works in concert with the cabinet's overall thermal management design.
 
Armored power resistors on the sink for the win. :)

amp-hv1.jpg
 
I noticed that the BU406D is not a BU406D, but a BU409. there's also a big diode tacked onto the backside of it. I saw in the faq that there are people who have had luck adding an external diode for damping, I'm guessing this is what it looks like? either way I'm gonna get the right part and be done with that.

I think people were doing that add-a-diode mod back in the day when then correct BU406D wasn't as readily available.

2: what's the best fpga AVG replacement available now? I see that there are a few options. I remember trying the fpga avg in my gravitar on my space duel and it really didn't like it. I'm guessing not all of them are created equal?

I placed an order yesterday and the only one I saw in stock was from Arcadeshop...?

3: what's a good thing to do with those big fat power resistors that are burning a hole through my pcb. I'm thinking a fan, but not sure if there's a more preferred way to do things

Watch the video I'm releasing today at 4pm ET (which you can already watch with early access as a channel member). I'm planning to add a second fan to the cabinet blowing directly onto the HV heatsink bar since this machine is intended for a public location.
 
That's some pretty terrible solder rework. I see several cold joints and most of the others are questionable. You should reflow them all remove all of the old solder and resolder those joints while you have it on the bench to undo the mods.

For the power resistors...I can't see them so I don't know which ones, but typically you should mount them high off the board. Keep at least 1/2" of free space between the resistor body and the PCB. And other components. Don't let them cook your caps! For bigger heaters, use bigger spaces. A fan shouldn't be required but it can help as long as it works in concert with the cabinet's overall thermal management design.
Yeah, I agree. The iron used was either set too low or was too small (low wattage.) That entire thing needs to be reworked with the right iron and fresh solder. Anything with that orange flux present.
 
I placed an order yesterday and the only one I saw in stock was from Arcadeshop...?

I see arcadeshop and alanone, there's also ttl versions floating around that can be made, don't know if there are any differences between the options available. I'll add pictures of the resistors for the fun of it, one of them has literally burned a hole through the PCB. I'll check out your video to see what kind of resistors you use.

20250414_121526[1].jpg20250414_121602[1].jpg

Besides the cruddy looking solder job due to the gunk I haven't washed off, I'm wondering if I should be concerned about this:
20250414_121946[1].jpg
 
I see arcadeshop and alanone, there's also ttl versions floating around that can be made, don't know if there are any differences between the options available. I'll add pictures of the resistors for the fun of it, one of them has literally burned a hole through the PCB. I'll check out your video to see what kind of resistors you use.

View attachment 813114View attachment 813115

Besides the cruddy looking solder job due to the gunk I haven't washed off, I'm wondering if I should be concerned about this:
View attachment 813116
Other than from a cleanliness perspective, unless the wires don't make contact with the pins (check the groud pin in particular), no worries about the neck connector.
 
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OMG! You changed it!!! :ROFLMAO:

But now I know which resistors are in question.

How did you attach them to the heat sink? Some kind of thermal epoxy? I don't see any mounting screws.

That's not my handiwork. But shows a typical "upgrade" to get the resistors away from the PCB and provide some better thermal management.
If I was to do that, I'd drill some holes and screw the armors into the sink fin. YMMV

As for the AVG, compare and contrast older options on Bill's archive page here ->
(It is concerning that perhaps newer AVG are getting difficult to find).

 
That's not my handiwork. But shows a typical "upgrade" to get the resistors away from the PCB and provide some better thermal management.
If I was to do that, I'd drill some holes and screw the armors into the sink fin. YMMV

As for the AVG, compare and contrast older options on Bill's archive page here ->
(It is concerning that perhaps newer AVG are getting difficult to find).


20240608_104511b.jpg




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Well it lives to display another explosion, or a few. I just ordered a bunch of shit from apar and shotgunned the heavy lifters. one of the big resistors was dead dead, 7924 was dead. the heat from the resistor killed c13. I replaced both regulators, replaced the bu409 (that was working, whatever) with the 406d, the diodes on the back got changed. I got the same resistors that charlie did, but I went the lazy way, instead of trying to land them through traces in the right spots, I mounted them up top and wired them through the holes the old resistors already burned through the board. I didn't have any screws on hand so I decided to use what I had on hand to mount them.

Red is not dead (yet)

20250426_013436.jpg20250426_030757.jpg20250426_030855.jpg

Thanks for helping clear up a few of my silly concerns.


On a side note, I've seen a lot of talk about replacement flybacks having the wrong anode to focus ratio while looking things up on klov, the focus can't get high enough to be sharp. I haven't seen this mentioned before, but does anyone think it could be a difference in voltage drop between the older anode rectifier diodes and the new ones in the repro flybacks? You think sticking another hv diode in line with the anode could rectify that? I don't know how much those diodes drop, but from what I understand, it's a lot more than a regular old diode.
 
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