Sorry, but it's another Asteroids playing blind thread

whitefox

Well-known member

Donor 5 years: 2016-2019, 2024
Joined
Jan 5, 2016
Messages
3,674
Reaction score
330
Location
Hockessin, Delaware
Sorry, but it's another Asteroids playing blind thread

For starters I apologize for this, I have been searching the forums for info on this. Problem is, I'm seeing results where the final fix was something that isn't broken on mine, or the thread ends up unresolved with whatever repair work got it working.

I have an Asteroids Revision 5 with an Electrohome G05-802 Issue 3. The game plays blind, spot checker is not on, no static or chatter on the tube. Neck glow. I placed my Asteroids Deluxe board in the game and no picture either, played blind.

I actually had this problem earlier, after testing the 12 pin molex up at the monitor I previously had a low voltage. This ended up being because of a short from the coin door connection. Unplugged that and it worked.

Now, the voltage up at that molex is fine. I pulled the deflection board and reflowed point on all the connectors, tested all the fuses.

So what do I test now. Do I open up the hi-voltage cage and test things in there? I've seen R900 & R901 be problems as well as the diode in the anode cable. Should I remove & test the diode?

Looking for other things I should look at here. This chassis was repaired by Chad, and it was working great until now with this problem. Could the problem be elsewhere?

Thanks for any help and assistance here.
 
Does the spot killer light go on briefly if you hit the reset button on the game board?

Also, you may be missing HV. Check by holding your hand against the front of the tube. You should feel some static electricity with the monitor on. No static, no HV, no picture.
 
Does the spot killer light go on briefly if you hit the reset button on the game board?

Also, you may be missing HV. Check by holding your hand against the front of the tube. You should feel some static electricity with the monitor on. No static, no HV, no picture.

No the light doesn't come on, I did see that in an older post and tried that.

No static electricity on the front of the tube.

I am thinking it's an HV issue I just am having the problem of where.
 
So, this is definitely a monitor problem. Right?

Did you do the basics?
- capkit
- check all semiconductors (diodes, transistors etc)
- check for cold-solder on components and headers
- look for broken traces
- check the wiring and connectors

In particular, you should rebuild the HV board.

Have you studied the FAQ? :)
 
So, this is definitely a monitor problem. Right?

Did you do the basics?
- capkit
- check all semiconductors (diodes, transistors etc)
- check for cold-solder on components and headers
- look for broken traces
- check the wiring and connectors

In particular, you should rebuild the HV board.

Have you studied the FAQ? :)

The faq doesn't have all the answers, sadly :)

Chad @ arcade cup repaired and did the initial work to the chassis (I sent him the entire metal structure + boards) so I would like to assume he went over a lot of things.

Voltages at the 12 pin molex are currently checking out. No, I have only cracked open the HV board once when initially troubleshooting this problem previously, things checked out good there but I did not remove the diode on the anode cable. Voltages coming out of the power block are solid.

Could there be something else preventing the HV from doing its thing? I don't mean a bad connection directly with it, but another circuit that is failing?
 
No the light doesn't come on, I did see that in an older post and tried that.

No static electricity on the front of the tube.

I am thinking it's an HV issue I just am having the problem of where.



If the spot killer LED isn't coming on when you press reset (or just unplug the game board), and you're hearing no chatter, that's a clue that there could be a power issue on the deflection board (which feeds the HV board).

Check to see if you have B+ on the deflection board. You should have around +34VDC and -34VDC on the + and - legs of the bridge rectifier on the deflection board. If those are good, see if you have 40VDC on pin 10 of P500, which feeds the HV.
 
If the spot killer LED isn't coming on when you press reset (or just unplug the game board), and you're hearing no chatter, that's a clue that there could be a power issue on the deflection board (which feeds the HV board).

Check to see if you have B+ on the deflection board. You should have around +34VDC and -34VDC on the + and - legs of the bridge rectifier on the deflection board. If those are good, see if you have 40VDC on pin 10 of P500, which feeds the HV.

What pin do I use for ground when checking this separately, 11?

Thanks for your help.
 
Pins 7 and 8 of P500 show ground.

Also, I may have been wrong above, as the text in the TM-151 Issue 3 G05-802 manual says HV supply is P500 pin 10, but the schematics show it as pin 6. 7 and 8 should be tied together to chassis ground though.
 
Pins 7 and 8 of P500 show ground.

Also, I may have been wrong above, as the text in the TM-151 Issue 3 G05-802 manual says HV supply is P500 pin 10, but the schematics show it as pin 6. 7 and 8 should be tied together to chassis ground though.

6&7 read 38.92, and I was wrong-spot killer light DOES in fact come on when you hold down the reset button on the board. No static build on the front of the screen.
 
Last edited:
I don't replace the grease, and I haven't had any issues. If you want to, you want to use silicone grease (aka spark plug boot grease), which you can get at any auto parts store. (Note this stuff is also excellent for lubing joysticks).

I actually remove all of the old grease, which has gone stale and turned waxy. You can dissolve it with Goof Off and some Q-tips. It will take a few rounds to get it all off.

You want to be careful when taking the old one apart, as there should be two small springs inside the boots that go on the HV diode. You want to get them out, and clean everything of the old grease.

Then when you put everything back together, if your boots are ok, they should hold snug. Though they often are stiff and dried out, and sometimes don't hold well, and you just need to make sure they are snug enough to make contact on both ends. If you don't have contact, you will get arcing, and they will heat up and smell of ozone, in which case you want to check the connections.
 
I don't replace the grease, and I haven't had any issues. If you want to, you want to use silicone grease (aka spark plug boot grease), which you can get at any auto parts store. (Note this stuff is also excellent for lubing joysticks).

I have plenty of silicone grease from all the cars I own, so that's good to hear. Thanks!
 
Got to put the new diode in today. Unfortunately, it tested bad (Big old fat 0 on the meter), as did the old diode. I put it in anyway, but as you guess, it didn't work. I did test the other two diode on the HV board since I Had it open, and they were just dandy.

I'll start looking around for these but if anyone knows of another source for a replacement, I'd appreciate it.

I did fine one at Arcade shop, should be good to grab it form them?

The diode I pulled out of it is labeled Varo H1809.
 
Last edited:
How were you testing the diode? You shouldn't be measuring 0 on any meter, particularly for an HV diode.
Here you go. No movement.

5c6612feb9fa0ea93d9231eaf2dfaf05.jpg
 
Oh, ok. 'OL' means overload (i.e., over-range), not zero.

That's normal, as you can't test a HV diode with a DMM, as you would a regular diode. However in your case it's moot, as the diode is obviously not the problem. (Or not the only problem, though there's a good chance your old diode may be ok.) The diode from ebay is functionally equivalent to the H1809 for these purposes (I use them regularly), so if that didn't fix it, it's something else.

Cap it, if you haven't already done so, and test all of the transistors. If it has the original Elna brand caps, they're likely bad.
 
Ran through the voltages this morning and everything still checked out. Pulled the deflection board and checked the transistors, two failed on testing, the other two are solid. On the two that failed you can see some visible charring or something on them.

Q607 & Q707 are the bad ones.

And yeah, not sure why chad didn't just replace those two caps. I'll do those as well.

On a good note, my Battlezone game has gotten better, finally figured out how to creep up an bounce the simple tanks. Those super tanks, though.
 

Attachments

  • 20170319_100057.jpg
    20170319_100057.jpg
    939.1 KB · Views: 39
  • 20170319_100118.jpg
    20170319_100118.jpg
    664.6 KB · Views: 28
Back
Top Bottom