Tempest Power-Off/On Help. Damage?

tybrad

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Hi all,
I have installed a switch on the extension cord feeding my Tempest machine because I do not want the machine running 24/7. The problem is that upon powering on, I must wait for some sort of self-check with the screen elongated and on a diagonal from the screen center to the upper-right corner of the monitor. And the wait until a readable/playable normal screen has increased dramatically in recent times so that now, it is on the order of 3hrs before I can play.

My questions are...
1. Am I doing short- or long-term damage by repetitively turning the unit off at its AC source?
2. Is there a "soft" power off switch somewhere that keeps power to central circuitry but "sleeps" the machine?
3. If the answer is "no" to #2, what is/are the option(s)?

Thanks all,
Tyler
 
1. Am I doing short- or long-term damage by repetitively turning the unit off at its AC source?
Assuming you power it up for each gaming session (like once a day) then no. From your description, I envision that you basically have a power strip with a switch on it. The main power switch does about the same thing by cutting the AC.

2. Is there a "soft" power off switch somewhere that keeps power to central circuitry but "sleeps" the machine?
No. Even if you could modify it do this, keeping any circuitry running constantly would be unnecessary excess stress. This would be a bad idea.

3. If the answer is "no" to #2, what is/are the option(s)?
Chances are pretty good that you have a failing game board, power supply, or something. You should investigate and fix it. Obviously in proper working order the game doesn't need to "warm up" as badly as you describe.
 
My first guess would be power supply. Are you able to check the voltages at the board?

If your 10.3 is low then so is your +5 and chances are good that the clock isnt running (I think its powered by the 10.3 on that game). Once the 10.3 gets good enough the game kicks on.
 
Thanks guys- this is helpful! This unit had restorative work done prior to my purchase but aside from a new flyback and a general checkup, I'm not sure what else had been done.

'fixer: I do have a DMM and can check. Although I am not an electronics novice and have done minor resto work on vintage audio equip, I will need a walkthrough with you. SO far, I have only fiddled with the N DIPs for gameplay and made minor monitor adjustments from the board pots.

Where do I begin?
 
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Thanks guys- this is helpful! This unit had restorative work done prior to my purchase but aside from a new flyback and a general checkup, I'm not sure what else had been done.

'fixer: I do have a DMM and can check. Although I am not an electronics novice and have done minor resto work on vintage audio equip, I will need a walkthrough with you. SO far, I have only fiddled with the N chips for gameplay and made minor monitor adjustments from the board pots.

Where do I begin?

There is a power circuit that will power a unit down when there is no activity and I want to build about 3 of them for powering down my monitors to prevent screen burn in.

http://forums.arcade-museum.com/showthread.php?t=225280

This is the circuit I was going to use for this. It is simple and will work.
 
OK, I am in the unit as I write this. All of the audio board voltages look fine- the 10.3 you spoke of is at 10.6v. All of the others are within 3-4% of spec. The frontmost of the two game boards shows 5.05v.

In looking around, I see that the entire unit has been recapped, what I believe are six new "can" trannys around the video board mounted on the metal plates- these end up very hot to the touch... except for a bottom-mounted one closest to the front of the monitor (warm).

The monitor is making what I would consider a louder than normal squeally sound that changes pitch slightly as graphics change.

Nudie pics of the interior are forthcoming.
Any ideas?

Thanks!
Tyler
 
There is a power circuit that will power a unit down when there is no activity and I want to build about 3 of them for powering down my monitors to prevent screen burn in.

http://forums.arcade-museum.com/showthread.php?t=225280

This is the circuit I was going to use for this. It is simple and will work.

Thanks for this. Is screen burn-in a problem with these since the graphics are in continuous change? Or are you thinking more along the lines of power savings?
 
Thanks for this. Is screen burn-in a problem with these since the graphics are in continuous change? Or are you thinking more along the lines of power savings?

This is for screen burn in for my two games, Operation Wolf and Heavy Barrel. The sound should tell them it is on but the screen will be off until a button is depressed or pushed down.
 
OK, I am in the unit as I write this. All of the audio board voltages look fine- the 10.3 you spoke of is at 10.6v. All of the others are within 3-4% of spec. The frontmost of the two game boards shows 5.05v.

In looking around, I see that the entire unit has been recapped, what I believe are six new "can" trannys around the video board mounted on the metal plates- these end up very hot to the touch... except for a bottom-mounted one closest to the front of the monitor (warm).

The monitor is making what I would consider a louder than normal squeally sound that changes pitch slightly as graphics change.

Nudie pics of the interior are forthcoming.
Any ideas?

Thanks!
Tyler

If it is a switcher type supply, I would just replace it.
 
Here are the nudies.

Top video board- what does that central pot regulate?
_DSC9505_zps81e5cf70.jpg


Bottom vid board
_DSC9506_zpsdec521c7.jpg


Audio
_DSC9507_zps90b1080a.jpg


Power board
_DSC9508_zps29c929cc.jpg


Game boards.
_DSC9509_zps38869e16.jpg


My screen
_DSC9510_zps583cabe0.jpg


_DSC9513_zpsbd2f59fe.jpg


Anyone see anything suspicious or see some adjustment that is required? On first glance, I see nothing indicating overheating or worse- anyone see a failure that I've missed?

kb0jjn: I am not familiar with what you're speaking about (switcher supply)? Where is it in these pics, and can you ID it as switcher or not? Thanks for staying with me here!
 
Top video board- what does that central pot regulate?
It adjusts the high voltage. If you tamper with that pot without the proper adjustment procedure your CRT may emit xrays and irradiate you. Do not twist knobs without knowing what you are doing, especially around a monitor.
 
It adjusts the high voltage. If you tamper with that pot without the proper adjustment procedure your CRT may emit xrays and irradiate you. Do not twist knobs without knowing what you are doing, especially around a monitor.

That's a-why I was a checkin' first
thumb_goofy-smiley-01.gif
 
Here are the nudies.

Top video board- what does that central pot regulate?
_DSC9505_zps81e5cf70.jpg


Bottom vid board
_DSC9506_zpsdec521c7.jpg


Audio
_DSC9507_zps90b1080a.jpg


Power board
_DSC9508_zps29c929cc.jpg


Game boards.
_DSC9509_zps38869e16.jpg


My screen
_DSC9510_zps583cabe0.jpg


_DSC9513_zpsbd2f59fe.jpg


Anyone see anything suspicious or see some adjustment that is required? On first glance, I see nothing indicating overheating or worse- anyone see a failure that I've missed?

kb0jjn: I am not familiar with what you're speaking about (switcher supply)? Where is it in these pics, and can you ID it as switcher or not? Thanks for staying with me here!

Your power supply is in the 3rd pic you posted and is usually a very good supply and will last some time.

The last few pics you posted looked like the sync is not right. That is something of an adjustment or a configuration. A monitor guy would have to weigh in here but if you see the colors change and can hear the game sounds then your trouble is not the cp but a video issue.
 
When you have weird images like that, I think it is the result of cold solder joints on the transistor connectors on the deflection board. On the 2nd photo, there are three red connectors with 6 wires going into them. With somebody else present, put your index finger on the top of one of the connectors and give it a gentle....I said gentle...push in one direction and then the other. Ask your helper to let you know if the image changes. Move on to the next one and try it as well. The two that will probably cause the image to change are the one beneath the big white resistor at the bottom of the photo next to the blue cap laying on its side. The other one is hidden by the wiring and it is next to the black square thingy (technical term) at the top of the photo. These are your x and y transistor feeds for neophyte terminology. If the picture gets better, you will have to pull the deflection board and resolder the pins at the bottom of the board where those connectors are. Whoever capped the board should have done that in the first place but it is often overlooked.

The 3rd red connector feeds the low voltage section and is probably not your issue.

Report back
 
When you have weird images like that, I think it is the result of cold solder joints on the transistor connectors on the deflection board. On the 2nd photo, there are three red connectors with 6 wires going into them. With somebody else present, put your index finger on the top of one of the connectors and give it a gentle....I said gentle...push in one direction and then the other. Ask your helper to let you know if the image changes. Move on to the next one and try it as well. The two that will probably cause the image to change are the one beneath the big white resistor at the bottom of the photo next to the blue cap laying on its side. The other one is hidden by the wiring and it is next to the black square thingy (technical term) at the top of the photo. These are your x and y transistor feeds for neophyte terminology. If the picture gets better, you will have to pull the deflection board and resolder the pins at the bottom of the board where those connectors are. Whoever capped the board should have done that in the first place but it is often overlooked.

The 3rd red connector feeds the low voltage section and is probably not your issue.

Report back
Thanks for the chime-in. I gently wiggled all of the red connectors (there were 4) and no change in the video. I also tried for other potential broken joints on other units on that board- nothing made a difference.
 
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Your power supply is in the 3rd pic you posted and is usually a very good supply and will last some time.

The last few pics you posted looked like the sync is not right. That is something of an adjustment or a configuration. A monitor guy would have to weigh in here but if you see the colors change and can hear the game sounds then your trouble is not the cp but a video issue.

Vector monitors don't have sync like rasters do. There is no adjustment that will correct this.

I'm about 60% sure this is a problem with the LV section of the monitor's deflection board. I've seen similar issues on B&W vector monitors; bad transistors or diodes in the preamp circuits prevent the deflection voltage from swinging, and you end up with X and/or Y axes smushed up into a corner of the display.
 
Vector monitors don't have sync like rasters do. There is no adjustment that will correct this.

I'm about 60% sure this is a problem with the LV section of the monitor's deflection board. I've seen similar issues on B&W vector monitors; bad transistors or diodes in the preamp circuits prevent the deflection voltage from swinging, and you end up with X and/or Y axes smushed up into a corner of the display.

Thanks ieure,
So what are my next steps? I do not have a roadmap for this kind of thing. Is the board in question the first or second pic?
 
I'm leaning towards the game board myself. The monitors power supply is easy to check.

Ground your meter to the metal chassis of the monitor and put the meter on DC voltages (if its not auto adjusting use the 200 volt scale). On the connector thats plugged into your high voltage cage the purple wire should read in the -27 area and the two red wires should read in the +27 area. Be carful not to touch the metal transistors with your hands or any metal tools. Also, if you were missing one side of the low voltage you wouldn't get high voltage so you wouldn't have a picture. I guess one of them could be low but I doubt it.

The game board is that big one in the 5th picture. There are lots of things on that board that can cause these sorta issues. The easiest thing to do though is to reseat the interconnecting harness between the two boards and reseat any sockets IC's on both board. DO THIS WITH THE POWER OFF! Instead of reseting IC's just push them into the sockets firmly to make sure they are in place.

Also, that interconnect harness is well known to have cold solder on the pins.
 
I'm leaning towards the game board myself. The monitors power supply is easy to check.

Ground your meter to the metal chassis of the monitor and put the meter on DC voltages (if its not auto adjusting use the 200 volt scale). On the connector thats plugged into your high voltage cage the purple wire should read in the -27 area and the two red wires should read in the +27 area. Be carful not to touch the metal transistors with your hands or any metal tools. Also, if you were missing one side of the low voltage you wouldn't get high voltage so you wouldn't have a picture. I guess one of them could be low but I doubt it.

The game board is that big one in the 5th picture. There are lots of things on that board that can cause these sorta issues. The easiest thing to do though is to reseat the interconnecting harness between the two boards and reseat any sockets IC's on both board. DO THIS WITH THE POWER OFF! Instead of reseting IC's just push them into the sockets firmly to make sure they are in place.

Also, that interconnect harness is well known to have cold solder on the pins.

Thanks 'fixer. I pulled the two game boards and wiggled/reset any IC's that were socketed, and wiggled/looked over the harnesses... with no change in the screen.

I pulled the LV harness and checked the voltages on red, red and purple- 0V. In fact, zero volts on all those pins! Screen is dead when harness is disconnected and on with the same problem with harness connected. I'm not understanding the 0v readings!
 
I pulled the LV harness and checked the voltages on red, red and purple- 0V. In fact, zero volts on all those pins! Screen is dead when harness is disconnected and on with the same problem with harness connected. I'm not understanding the 0v readings!

Did you pull just the connector off of the high voltage cage and test that or all of the connectors off of the monitor boards?

Make sure that your probe is making contact with the metal in the pin. Theres no way that your getting a picture and having 0 volts there.
 
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