Need my G05-801 repaired or replaced

[Reddogg]

More readings

I noticed some pins missing in my harness, and was wondering if everyone else has the same ones missing. Going by this pinout:

http://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=pinout&page=Asteroids.txt

I am missing pins J,K,W,7,19

Also, with the power on and the harness off (no load condition), my readings on the harness pins are:

pins B,and 2 (+5V)...reads 6.12
pin X, and 20 (36 VAC)...reads 17.5
pin Y (+5V)...reads 5.55

On the Audio Regulator board:

Test loop 10.3VDC...reads 9.8
Test loop +5VDC...reads 5.0

On the Asteroids PCB:

Test loop +5VDC...reads 4.77

I am unsure about testing voltages going into the EHT cage (P900). I haven't yet found the pinout and expected voltages for P900.

 

[HudsonArcade]

Funny how people make wrong suggestions, call names, and run away without giving any actual help, isn't it?

How are you measuring the voltages?
P100 only makes sense as AC with respect to ground.

If you're getting 54VDC on 1/2 with respect to ground (3/4), you've probably got blown zeners, so you're getting full bleed through the power transistors.

If that 54V is on 1/2 with respect to 5/6 then you're probably actually getting +/-27VDC which is fine since the regulators are unloaded w/ the deflection board unplugged.

Are the P703s AC or DC? Too low for a working game if AC... Y seems a little high if DC....

 

[HudsonArcade]

Also, with the power on and the harness off (no load condition), my readings on the harness pins are:

pins B,and 2 (+5V)...reads 6.12
pin Y (+5V)...reads 5.55

Meaningless w/o the board hooked up.

pin X, and 20 (36 VAC)...reads 17.5

36VAC is from X to 20... should be ~18VAC to gnd from both X and 20.

On the Asteroids PCB:

Test loop +5VDC...reads 4.77

If the +5 measurement on the ARII is significantly different from the +5 at the board, you should repin the harness... (actually if you've got brass solid pins instead of split pins, you should replace them all anyway). 4.77 is a little low, but should still work... you can tweak it up with the pot on the ARII.

 

[Reddogg]

Pins 1 and 2 on P101 of the Mon. Reg. board now read 43 VDC with respect to GND pins 3/4 of P101.

Only pins 3/4 are GND from what I can tell, and pin 5 says -25 and/to -35, pin 6 is a key slot, and pins 7 and 8 should measure 6.3 VAC.

For P703 on the deflection board, the manual says:

pin...description...impedance...Voltage

1...X...1K ohms...+/-10v (0v center)
2...GND
3...Y...1K Ohms...+/-7.5v (0v Center)
4...GND
5...Z...220 Ohms/min....0.5v blanking
1.0v off
4.0v full on
6...Key
7...GND

Doesn't seem like the readings I took for P703 really mean anything.

Meaningless w/o the board hooked up.

36VAC is from X to 20... should be ~18VAC to gnd from both X and 20.

If the +5 measurement on the ARII is significantly different from the +5 at the board, you should repin the harness... (actually if you've got brass solid pins instead of split pins, you should replace them all anyway). 4.77 is a little low, but should still work... you can tweak it up with the pot on the ARII.

Both pins X and 20 each measure 17.5 VDC to GND.

I tried to adjust the +5v on the Audio Reg. board, but with it as high as 5.20, I still only got as high as 4.98 on the +5v test loop on the Asteroids pcb.

Thanks for the help by the way!

 

[HudsonArcade]

If you're getting 43 on 1/2 w.r.t. 3/4, you've got a blown zener or a shorted transistor... check 'em both....

worth checking the voltages across R100 and R101 with the game powered up to make sure the bridges are good... they should be about the same (DC), but opposite polarity.

The input specs on the deflection board won't tell you much... that's all determined by what's being driven from the game board.

 

[Reddogg]

Well, I've replaced the zener diodes (ZD100, ZD101) on the mon. reg. pcb., and all 4 on the deflection pcb. I also replaced D100, and D101 on the mon. reg. pcb.

I put in a new connector and header pins at the deflection pcb P703.

I still had no change.

So, I began checking all of my transistors on the deflection pcb and found several to be bad.

Q503, Q601, Q630, Q730---all TIS98 transistors. Unfortunately however, I can't find a suitable replacement anywhere. NTE cross-references with their part NTE123AP, but it's not at all the same. Is it a suitable replacement? I need 4 of them.

Also, Q604, Q605, Q704, Q705---all MPSU57 transistors that cross-reference as NTE189.

And Q606, and Q706---both MPSU07 transistors that cross-reference as NTE49.

WOW! That's a lot of bad transistors considering it supposedly sat in storage for 10 years, and worked prior to going in.

Does anyone know if NTE123AP can be used as a suitable replacement for TIS98?

 

[HudsonArcade]

Q503, Q601, Q630, Q730---all TIS98 transistors. Unfortunately however, I can't find a suitable replacement anywhere. NTE cross-references with their part NTE123AP, but it's not at all the same. Is it a suitable replacement? I need 4 of them.

2n3094 or 2n4401 are fine

Also, Q604, Q605, Q704, Q705---all MPSU57 transistors that cross-reference as NTE189.

And Q606, and Q706---both MPSU07 transistors that cross-reference as NTE49.

Central still makes CENU07/U57... bob carries them...

Avoid NTE wherever possible...

Did you check the picofuses?

 

[Reddogg]

Did you check the picofuses?

No, but I just put them in so they "should" be good.

Can all these transistors be the reason for my spot killer? Everyone says the input signal, but I've tried that. I know the voltage needs to be correct also, so am I right that it makes sense that these transistors not properly "handling" the power could cause the spot killer?

I've got things going on here that I haven't read from anyone else.

If I can get this working 100%, then this thread might serve useful.

I just put an order in with Bob, so the transistors are on the way.

Anything else I can check in the meantime?

 

[Reddogg]

Well I replaced the transistors, but I had to modify all of the u57s and u07s to fit, because the only ones I could afford from Bob (the heavy duty ones) are too big. So, I had to drill new holes in them, but after doing this, I couldn't get the screws on on 2 of them. I applied solder to the metal tab and the screw that sticks thru it thinking that would be good enough, but upon powering the game up, I had not only smoke, but FIRE on R10 and R11 (on deflection pcb)!

Just before that happened, I had the same symptoms I've been having.

I am completely frustrated by this thing! Apparently I have the "toughest to bring back to life" Asteroids machine on the planet!

Does anyone have any more ideas on anything that I could try or what to test (and how to test)?

I am literally at my wits end, and I've spent $150 in parts just trying to repair the machine ($100 on the monitor alone)!

Obviously, I don't completely know what I'm doing here.

If anyone in so. cal. is willing to help in person, that would be amazing! And of course the beer is on me!