Tempest Assistance needed

MC35

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OK, I've done alot of work, and I've referenced many threads and resources. here is where I'm at.
Spot Killer on, Players 1 and 2 leds flashing.

Monitor cap kit, LV2000, frame transistors replaced. I have not connected the HV cage yet, only the main boards, all other boards connected.

No ripple in the PS all test point voltages on the AR board seem good except the 36VAC is low, but all DC voltages are good. I did replace the 3055 for 5 volts to get the 5 volts back up.

6.8V on the main board is around 4.8, all other test points are good.

I found some cold solder joints connecting the main board with the AUX board. Fixed that, now it appears to play blind with the Spot killer on and static in the speaker.

X and Y out don't have ripple and are relatively low. DAC's at A10 and F10 have good signals.

I have limped this to the point of playing blind but I don't want to plug in the HV cage until I can isolate the spot killer. Any other tips, or places to check?
 
Playing blind does not mean you have X/Y OUTPUTS working correctly.
If you don't have DC and AC on XOUT and YOUT, then you have issues. Thus the spot killer is "on".

Best to use a scope, but can use DVM to validate too.
 
Playing blind does not mean you have X/Y OUTPUTS working correctly.
If you don't have DC and AC on XOUT and YOUT, then you have issues. Thus the spot killer is "on".

Best to use a scope, but can use DVM to validate too.

OK, I have a scope, but not sure what the signal should look like. I can eaisly test and send results. Please specify
 
alright, something just happened. I left the board turned on, Monitor not plugged in, and now the X out is 10.75 DC, Y out is -6.65.

DAC signals 3-11 (A10, F10) are now low, not pulsing. 2 is HI.

won't play blind either.
 
Well, now you have other issues ... once fixed then you can test the final output by doing the following ...

You have scope? Hallelujah. :)
What type? Analog or digital? Know how to use it? Need two probes - one for XOUT, one for YOUT.

Disconnect monitor plug. Put probes on XOUT and YOUT test points on logic board.

X or Y look similar to:

asty_scope_x.jpg



XY mode - you'll see the game (if working correctly). Don't be concerned with the trace lines.

maxresdefault.jpg


maxresdefault.jpg
 
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pulled the vector Generator Rom at R3 again, and now the X and Y don't have the DC as listed in my last post.

WTF?
 
Well, now you have other issues ... once fixed then you can test the final output by doing the following ...

You have scope? Hallelujah. :)
What type? Analog or digital? Know how to use it? Need two probes - one for XOUT, one for YOUT.

Disconnect monitor plug. Put probes on XOUT and YOUT test points on logic board.

X or Y look similar to:

asty_scope_x.jpg



XY mode - you'll see the game (if working correctly). Don't be concerned with the trace lines.

maxresdefault.jpg


maxresdefault.jpg


Connected and looking good on a scope.
Now what?
 

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it appears to be playing fine and going through the test modes. I think I have a bad or several bad rom sockets. I am getting intermittent issues in that area. The fire button also seems to be stuck

I will read through Andrew B's thread.
Thank you!
 
disregard, I have read through this and that is what has brought me to this point. I'm not sure his guide will help me much further.

What voltage settings is your o scope on to get the waveform for x and Y out in the image prior to seeing the game play
 
alright, something just happened. I left the board turned on, Monitor not plugged in, and now the X out is 10.75 DC, Y out is -6.65.

DAC signals 3-11 (A10, F10) are now low, not pulsing. 2 is HI.

won't play blind either.

Don't want to side track you but going back to this and reading 6100 FAQ and AndrewB's guide...aren't these level of voltages on your x and y out bad?

from 6100 FAQ. (not sure why it says measure at r600 and r700 instead of the j/p100 pin 7 & 8 with deflection board disconnected) Haven't looked at schematic but those are likely straight from x y output test points on pcb.

Important: It is possible for a failure on the game logic board to cause the monitor to fail. There is a simple test to find out if the game board caused the monitor to fail. To perform the test you will need a voltmeter. Set the voltmeter on the DC voltage scale and measure the voltage on the lead of R600 and R700 (fuses) of the deflection board. These are connected to the plug with wire colors yellow (R600) and orange (R700). The correct voltage should be in the +0.5 to -0.5 volt range (basically zero volts). The voltage will fluctuate because of changing deflection signals. If the measured voltage is between 5 and 15 volts (positive or negative), then check the X and Yamplifiers on the GAME board. Also check for broken potentiometers on the game board.
 
Don't want to side track you but going back to this and reading 6100 FAQ and AndrewB's guide...aren't these level of voltages on your x and y out bad?

from 6100 FAQ. (not sure why it says measure at r600 and r700 instead of the j/p100 pin 7 & 8 with deflection board disconnected) Haven't looked at schematic but those are likely straight from x y output test points on pcb.

Important: It is possible for a failure on the game logic board to cause the monitor to fail. There is a simple test to find out if the game board caused the monitor to fail. To perform the test you will need a voltmeter. Set the voltmeter on the DC voltage scale and measure the voltage on the lead of R600 and R700 (fuses) of the deflection board. These are connected to the plug with wire colors yellow (R600) and orange (R700). The correct voltage should be in the +0.5 to -0.5 volt range (basically zero volts). The voltage will fluctuate because of changing deflection signals. If the measured voltage is between 5 and 15 volts (positive or negative), then check the X and Yamplifiers on the GAME board. Also check for broken potentiometers on the game board.

Yes, those voltages are high and will cause damage. They weren't there the whole time. The x and y out are now back to close to 0. This was a problem with the vector generator ROM. I reseated it and it's back to normal. The question I have is, if I am able to see the game on my scope in x/y mode, does that mean the board is fine and I need to look more into the monitor. The board ROMs are sketchy. At a minimum I need to replace a few ROM sockets and possibly a few ROMS. It's hard for me to know if this is a monitor problem or ROM problem when I know the image on the scope is intermittent due to ROM sockets.
 
You can try this.

1. keep scope connected to confirm good X/Y outputs
2. connect the monitor
3. confirm no spot killer

If you still get spot killer when scope is showing vectors, then you know the deflection board has issues.

Ideally, if you suspect the sockets are bad on the logic board, you need to resolve that. (I assume you've also resoldered the interconnect cable)

Do you own a HV probe?
 
If the game board is playing blind, test your AC and DC voltages on the X/Y OUT test points on the game board without the monitor connected, to make sure they are safe.

However if you had your monitor connected with the DC voltages mentioned above, your monitor is likely fried. Start by testing the frame transistors per my guide. You may have multiple interconnected issues.
 
The monitor was not connected when I measured those voltages. What I need to know now is, if the game plays fine on my scope, then is it absolutely safe to say I have a monitor problem.
 
I did reflowed the solder on the interconnect and ROM sockets are good now.

No, I don't have a high voltage probe.
 
One thing that has bitten me a couple times with using a scope for Atari vectors is that a scope is by nature much more tolerant of offset voltages than a 6100. Which is to say, you can adjust the XY size and position pots on the board such that they're generating an image which the scope will show just fine, but the 6100 will not. Simply having maladjusted size/position pots can produce the exact effect you're experiencing. I'n not saying this is or is not your problem, but you should rule it out before going deeper, because it's simple and not always obvious.

Power up your PCB in test mode, so you get the crosshatch screen. With your scope in YT mode, connect your channel one ground clip AND PROBE to the X test point. Adjust your scope so the flat line is exactly in the center of the graticule. Leaving the ground clip alone, hook the probe to the X OUT test point, and adjust the X CTR pot so the waveform is centered on the center line of the graticule. Then adjust X SIZE so the peak-peak voltage is no more than +-8v.

Repeat with the Y axis, except max P-P is +-6v, and using Y CTR / Y SIZE pots (obviously).

If all that looks good, hook it up to the 6100 and see what happens. If you can't adjust to stay within the peak-peak voltages, you have an analog video output issue on your PCB. Check the +15 / -15 regulation and swap TL082s, these are the most common issues.

A lot of golden age boards have terrible sockets. The worst are the ones with the upward angle on the outside of the long edges, and the white plastic strip on the underside. I recommend replacing those with 3M open-frame dual-wipe sockets whenever you encounter them.
 
You probably have multiple overlapping issues. Most Tempests do. And especially if your monitor is original, I can almost guarantee you have issues there, in addition to what's going on with your game board.

You don't really need a scope in this case, as that's really only needed if you're troubleshooting the analog section of the game board. You can determine if the output voltages are ok with a DMM most of the time, at least enough to tell if it's safe to connect your monitor, and you can tell if the game is playing blind without the monitor, to know if the CPU is working or not.

Measure the XY out voltages per the values given in my guide, to make sure both the AC and DC levels are in the safe ranges, and if so, you can connect your monitor without fear of damage.

However, the above doesn't apply if your game board is misbehaving intermittently, as the voltages can be ok, and then the game board freaks out, and sends excessive DC on the XY outs to the monitor, and poof, your deflection board and/or frame transistors are toast. So it's very important to make sure your game board is solid and reliable before connecting your monitor.

Also, it's usually not so much the sockets that are the issue with Tempest and other vector boards, as it is the ROM legs themselves. The sockets are gold plated, so they actually don't corrode much. What does corrode is the spot on the ROM leg where it contacts the socket, in addition to the dust and dirt that gets inside the socket, and the lead and tin oxides that build up on the ROM legs. The dirt and oxides are what typically cause intermittent issues, and replacing the sockets is actually overkill in most cases.

I blast the inside and outside faces of all of the ROMs with my Dremel wire wheel brush, then hit them and the sockets with DeOxit, reseat each ROM a couple of times, and that takes care of 99% of socket-related issues, while still keeping the sockets original.

Once you are sure that your XY voltages are good and solid, and the game plays blind without resetting, you should tackle the monitor separately.

Color vector systems are VERY interdependent, meaning an issue on one board will often cause other boards to blow. For example, a misbehaving game board can easily fry your deflection board, and when the power supply section of the deflection board blows, it can easily take out your HV board. So it's important to go over everything fully before firing up, and not try to swap boards in and out of color vectors to try to troubleshoot issues, as you will often just end up with more blown boards.

If you follow the step-by-step procedure in my 6100 guide, it may help you find issues with your monitor without causing extra damage. But the important part is fixing all issues before firing it up, else you run the risk of chasing your tail.
 
^^ dude, post #7 he shows tempest playing on his scope. Really, scope not useful? LOL :rolleyes:

Fix the bad connections, cross your fingers, and power up the K6100. Go for it.
 
^^ dude, post #7 he shows tempest playing on his scope. Really, scope not useful? LOL :rolleyes:


The scope is a 'nice to have', but leading people to believe they need one to work on these is misleading, as A) most 'average user' folks don't have them, and B) most of the time you don't really need one for these, as a DMM tells you everything you need to know in terms of knowing if it's safe to connect a monitor or not.

A scope also won't tell you if your DC levels are in the danger zone, if you are viewing the signals in AC-coupled mode (which is what you should be doing anyway, just to be safest for the scope).

You can have your X/Y centering pots maxed out, and have the DC levels well in the danger zone, and the scope display will still look fine when you are AC coupled. So I always measure the DC and adjust it with a DMM before connecting the monitor, even when I use my scope as a display.
 
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