Sorry, but it's another Asteroids playing blind thread

The large Elna filter caps on the deflection board are almost certainly ok. (I was referring to the ones in the HV cage.) Those large caps don't naturally go bad like the small ones do (and they can be a little pricey), so we typically don't replace them during a recap, unless they're physically damaged.

If two of the heatsinked transistors are testing bad, you may have other issues (possibly, but not guaranteed). You should test all of the diodes also in that area, as a shorted one with sometimes take out the transistors.

The MPSU-07 and -57 transistors can be replaced with more modern substitutes. See Bill's page for details:

http://www.biltronix.com/transistor_subs_01.html

I use the ZTX653/753's, but they take a little work to install. You have to get the correct heatsinks for them (also on the page above), and drill holes in the heatsinks, to bolt them to the larger sinks. Also, the orientation of those transistors is opposite of the original ones (see the datasheets and the PCB markings to align B, C, and E). But once you take care of these things, they work well, and are super cheap compared to the original parts.
 
You should test all of the diodes also in that area, as a shorted one with sometimes take out the transistors.

Wow there are a lot of little diodes on this board. Nothing came up problematic on those.

Yeah, I was wondering if something else may be a culprit causing these two transistors to fail. Thanks again for your help on this.

Security90210 has the original transistors in stock, I'm going to go with those since it'll be easier for me to install. I have a slew of other doodads I need to get from him as it is, once he gets a custom kit together for me I'll place the order.
 
Security90210 has the original transistors in stock, I'm going to go with those since it'll be easier for me to install. I have a slew of other doodads I need to get from him as it is, once he gets a custom kit together for me I'll place the order.



Order extras, in case the new ones blow right away due to something else being wrong. (And it never hurts to have spares anyway.)

Those transistors are used on most vector monitors, so they're good to have, if you have other games.
 
Order extras, in case the new ones blow right away due to something else being wrong. (And it never hurts to have spares anyway.)

Those transistors are used on most vector monitors, so they're good to have, if you have other games.

thats my philosophy when I do monitor repair, I order stuff I dont need :p
 
Light Show

I was finally able to install the new transistors tonight. The game initially came up great. Adjusted the contrast/brightness pots let it run for a while, everything seemed solid.

Perfect time for a cigar celebration! That was about 45 minutes. Came back in to put the game back together and install a new HighScoreSave kit that Joe sent to me after the previous one produced a problem that Andrew discovered. I was running a non-online kit in the meantime. Turned the game on and while it was in the HSS Intro screen, I started seeing flashing. I will break down the timeline.
  • Replaced Transistors
  • Powered up with HSS Offline save Kit, no video but screen static, turned off
  • Cranked up Brightness / Contrast pots
  • Powered up, saw video, ran for 10 minutes adjusting screen brightness / contrast pots
  • Turned off to take a cigar break, 45 minutes
  • Pulled board, replaced offline kit with online kit, powered up, after 30 seconds in intro screen started seeing slow flashing of video. Turned off. Slow flashing while it was powered down. About 5 seconds after shutdown and screen was dark, I saw the center dot appear brightly and fade out.
  • Pulled board, removed HSS kit and put CPU in, tuned on, saw light show almost immediately, got a quick video
Here's a short video, didn't want to leave it on for long:
https://www.instagram.com/p/BSR9oKugMcE/

That rules out the one variable (the kit) that I changed out from it's initial power on that ran fine, to the latter runs that are showing a problem. Time to hit the FAQ again.
 
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Looks like a monitor problem. To confirm, power up the game with the monitor unplugged. Does it play blind?

It looks like the deflection board was jacking the brightness all the way. Could be numerous things. Test all of the diodes and transistors on the deflection board, and look for any damaged/burned components.

I wouldn't rule out something in the HV cage either, but I'd suspect deflection first. It's very common to have things fail within an hour of rebuilding any one part of them, in a system that hasn't worked right for a long time, after decades of use.

This is why it's important to rebuild (or at least test) all parts of the system, else it may take you a few rounds to get all of the bugs worked out. Even then, many of the parts are old, and you can't always predict what's going to blow. So you can fix one thing, and a day later, something else goes.

Bottom line - check the work you did, and suspect the stuff you haven't replaced yet.
 
Bottom line - check the work you did, and suspect the stuff you haven't replaced yet.
First thing will be putting the old diode back in the anode. I did not see or hear arcing, but... I also bought caps for that board as well, didn't remember if chad replaced them or not.
 
Put the old diode back in. Didn't get any video. I am pretty sure I saw a bit of arcing or something while it was on in the cage, it was faint and quick, not a dramatic lightshow that I've seen videos of.

When I opened the cage to do the replacement, it's apparent that it was arcing previously with the new diode. Some charring on the cage itself and surrounding components.

My question is, did I install the diode incorrectly? Maybe the grease I am using is conductive? Where and what exactly should I be greasing? I am not seeing a good explanation of this last part. Page 13 of the FAQ doesn't detail it either.

I'll dig back into it tonight and retest everything in there.
 

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I wouldn't (and don't) use grease. But if you do, pure silicone dielectric grease should be ok, and is the only thing I'm aware of that I would use. (That's not to say there isn't anything else, but I just don't know about it.)

The thing about the grease is that it sort of requires the boots to be airtight, so they grab the diode snugly, and you are sure you're getting solid contact between the leads on the diode, and the springs (and also between the springs and the metal caps on the ends of the wires).

But in many/most cases I've seen with these HV units, the boots are old and either charred and/or just dried out, so they don't grab tightly enough to get suction on the diode. So if you add grease to that, it just makes it easier for them to push themselves off, and create gaps, which results in arcing.

I've tried soldering the diode leads to the tips of the springs, to try to combat this. It's a little tricky, as you need to dremel wire wheel the springs to expose bare metal, in order to get the solder to stick. But it has worked.


Also, direction-wise, the white band goes away from the flyback (i.e., towards the tube).
 
Also, direction-wise, the white band goes away from the flyback (i.e., towards the tube).

Thanks. I guess my concern on installation was with contact points and the grease. Got the direction part down, and of course triple checked before closing it up. :)

I'll give the boots a good cleanup as well.
 
Cleaned everything up, put the ebay'd diode back in, tested some things. Got the pulsing picture again.

I'll do one final test and put the game board in asteroids deluxe. Who knows.

So, Andrewb, do you repair chassis? :)
 
Looked over the problems I'm having at lunch today, it appears the game is resetting itself in a boot loop, nothing is moving in the video. It's hard to see from the quick pulsing. I figured it was a monitor issue doing this. Alright, that gives me a better plan of testing tonight.
 
Check and reseat your ROMs first. If you have a logic probe, checking pin 40 of the CPU will tell you if it's resetting (if it's toggling). You can also try booting with the test mode switch on (vs flipping it on after power up), and see if that makes any difference, just to get more info.
 
Oh I've got a good one now.

Asteroids Deluxe boots fine in Asteroids.
Asteroids boots fine in Asteroids Deluxe.

Hahaa. Yay!

So Asteroids in it's cabinet is still resetting or something, now the buttons & spot killer LED are both flashing, so I'm guessing it's still resetting. But why would AD work in it just fine?

I'll do the board checks later this weekend and also the voltages off the brick and A/R.
 
It's really the +5 voltage on the boards that matter. Measure each one, on the board, with respect the ground on the board, in each cabinet. Then adjust so they are the same, and see if the behavior changes. You might have one board that is sensitive to voltage, and it may be higher in one cab than the other.

Each board may not be drawing the same current either (and/or the edge connectors may be dirty), so the delivered voltage on each PCB is what matters most.
 
Had to adjust the +5Volt so that the board is now getting 5.07, it was 5.2 before. Not sure why that changed.

Game is now playing to a point. Only thing that shows up on screen is the player ship and ufo and bullets. Same thing happens when I put Asteroids Deluxe in here now, Asteroids in Asteroids Deluxe displays fine.

Time to go over some connectors.

Edit: I am an idiot.

Had to adjust the brightness & contrast. That's what caused the other graphics to not display.

Now to wait 45 minutes (and enjoy a cigar on the deck) and hope it still works. :D

So for the sake of proper adjustment, is that what that small box thing is for in test mode? Or is there a screen shot / video I can use to set proper brightness & contrast?

https://www.instagram.com/p/BSuVlfTgzFG/
 
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Here's the process I use to adjust b/w vectors:

- Turn brightness and contrast up all the way. (You will see retrace lines, and that's ok).
- Dial back brightness until the retrace lines and dots can no longer be seen.
- (Optional) Dial back contrast to taste.

Personally I like to leave the contrast up all the way on my games, as I personally like the way it looks, and my games are not on 24/7. If you do leave your games on for long hours, you may want to dial back a bit.
 
Here's the process I use to adjust b/w vectors:

- Turn brightness and contrast up all the way. (You will see retrace lines, and that's ok).
- Dial back brightness until the retrace lines and dots can no longer be seen.
- (Optional) Dial back contrast to taste.

Ah good. I may bring it down on mine, the persistence/trails of things moving around the screen gets to me, but this is helpful.

Thanks again for your help on this!
 
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