Need my G05-801 repaired or replaced

What's wrong with your 801?

There really no harder to fix than an 802.. just have to worry a little more about the regulator board, and the picofuses are a bit of a pain in the ass...
 
I've been trying to fix for a while. Everything recapped, deflection headers re-flowed, transistors changed out, all fuses check out, but still spot killer and white dot on screen.

I believe it needs to be hooked up to an o-scope to verify it actually works, 'cause I can't figure it out.
 
It's playing blind, and in test mode I can hear all the right beeps for the buttons I'm pushing, but still the same screen-white dot.

While I'm trying to track down a monitor, I'll start over with this one from the beginning. It's totally possible I overlooked or forgot to check something.
 
Woa...just came across some posts about "neck chatter" and I found it in the cinamatronics vector monitor FAQ as well.

I have no neck chatter on power up. The neck is very bright, but no sound from it at all.

So, looks like I've something "new" to check out.

Any thoughts or hints anyone?
 
Test R100 & R101 to make sure that they are not open.

Well...looks like I've got good news (I knew I must have overlooked something). Both R100 and R101 on the monitor's regulator board tested open (I get a solid 1 when testing for continuity with my DMM, after desoldering and removing one of the legs).

They're both 10K 1/2 Watt 5% resistors. But can someone confirm that they're supposed to be mounted in opposite directions (I don't know if someone ever tried to repair this thing or not, so I just want to verify)? R100 has the banded side on the left, and R101 has the band on the right, correct?

Also, are they sensitive to heat and should I go slow and be careful while installing them?

Hopefully this moves me closer.

Thanks Dokert and everyone else for patience with the newbie :)
 
"R" stands for resistor. They can be installed in either direction. Pretty much any other part (caps, diodes, ect) needs to be checked for polarity. Resistors (as long as they are not a "resistor pack") are not polarity specific.
 
FYI - I think you can find these resistors at a Radio Shack, believe it or not. But if not, no need to replace them. Just remove them and solder a heavy piece of wire in place of each one. Yes this is a factory approved mod. Those resistors are prone to extreme heat and do tend to go bad from it. The factory later removed the in the later revisions.

DO NOT DO THIS. HE HAS NO FUCKING CLUE WHAT HE'S TALKING ABOUT.

This is a G05-801, not an 802/805. Pay some fucking attention before you post dangerous and stupid advice.

R100 and R101 are just there to discharge the filter caps on the far side of the bridge on the regulator board.... They're 10k -- should test "open" using a continuity tester. As long as they're not shorted out, they're completely irrelevant, and don't affect the operation of the circuit -- all they do is discharge the caps for 'safety' after the monitor is powered down.

If you replace them with a jumper wires as this dolt suggested, you'll be shorting 5A of current straight to ground... fortunately, the fuses should blow before the wires overheat and catch the board on fire.

For starters, unplug P101 and measure the +/- 25V there... if your regs are blown you won't get any action out of the deflection board.... If the voltages look good, measure agan with P101 plugged in, to make sure the deflection/HV aren't going overcurrent and dragging the voltages down.



On a GO5-802/805 R100 and R101 form low pass filters with C100 and C101, but if B+ or B- is shorted out (common with bad chassis transistors), they can suck up to 25W before the fuses blow, and they're only rated for 10W, so quite often they'd blow on dead monitors. Atari realized the low pass filter really wasn't doing much good, since the primary frequency was only 120Hz, and the resistors were blowing when deflection failed since they were under-designed, so they were replaced with jumpers on some late models and by ops doing repairs.

Of course, you really can't just blame orion for his dangerous suggestion... it was Dokert who made the utterly useless suggestion to test R100/101 that led him down that path.
 
FYI - I think you can find these resistors at a Radio Shack, believe it or not. But if not, no need to replace them. Just remove them and solder a heavy piece of wire in place of each one. Yes this is a factory approved mod. Those resistors are prone to extreme heat and do tend to go bad from it. The factory later removed the in the later revisions.

DO NOT follow the instructions listed above.

DO NOT replace those resistors with wire.

Looks like they tested out fine with what you have posted.
 
Wow! Thanks for the warnings guys!

The resistors are cheap as hell (.99 for 5), so I just replaced them for good measure anyway.

Won't be home for a couple of days. I'm going to re-check all voltages when I can, and take care of this once and for all!
 
For what its worth, I mis-read the model number, thats all.

"He has no fucking clue what he's talking about" seems a little extreme for an honest mistake. I'd like to think after fixing several of these I have at least a clue.
 
For what its worth, I mis-read the model number, thats all.

"He has no fucking clue what he's talking about" seems a little extreme for an honest mistake. I'd like to think after fixing several of these I have at least a clue.

I see that you mis-identified the model, no biggie. The nasty Troll like remark from the other poster is his norm, so don't take it personally.
 
Okay guys, I took some readings, and some are way off according to the G05-801 manual.

Into the monitor regulator board (P100):

Pin/ DMM reading

1/ 32.3
4/ 32.3
6/ 6.5

Out of the monitor regulator board (P101):

Pin DMM reading

1/ 54.4
2/ 54.4
5/ 0.0
7/ 0.1
8/ 0.1

Deflection PCB (P703):

Pin DMM reading

1/ 0.6-1.2
3/ 2.5-5.7
5/ 0.7-0.9

Again, the game is playing blind with the spot killer on, and a white dot on the screen (the white dot does fluctuate/change in intensity as the game is playing blind). All sounds work, so I didn't bother testing the Audio Regulator board.

P101 on the Monitor Reg. board looks way off to me. Probably need to replace C100 and C101 on the Mon. Reg board? I haven't heard of that being a reason for the spot killer though.

Thoughts?
 
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