g07 blue screen

tron guy

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Well slackmoe has been helping me through this via pm and I've come pretty close to getting this going.

I am working on a dead chassis that I bought that was missing the hot and vr. I capped it with the arcadepcup rebuild kit, new flyback, new width coil, new hot, new vr, I reflowed solder all over the place.

I was getting nothing on video and discovered a couple of small cracks near #10 of the flyback. Anyway got that "fixed" and I get video now, only it's none of the game. Just a blue screen with a few lines through it. (wacko by the way)

Put my other chassis back on, perfect. Put this one back on, blue screen. I would say that the blue screen is very close if not perfectly the blue that wacko has anyway.

bottom line, I'm not getting any game play to show up on the screen.
 
Turn the blue all the way down. Anything?

Disconnect the video connector. Still blue? Remove the blue drive transistor and retest...
 
ok I tested it with the video inputs disconnected, virtually the same screen, it may have been scrolling a touch, but I did mess with some pots last night so that could be the cause of that.

Which of the 3 transistors should I remove? I can't easily tell which one is for the blue.



One other question:
As I compare the neck board of this 'faulty' chassis to the working one I am looking at I see some of the big resistors that are upside down compared to the working one. Meaning a specific colored stripe is inserted the opposite direction of the working one. Any chance this matters? I didn't think so, but I can't remember.
 
Resistor polarity doesn't matter.

Next, unplug the 5-pin connector from the chassis to the neckboard.

A) If it stays blue, then remove X101 on the neckboard and try again. If so, swap that transistor you pulled with X102 and put the transistor from X102 into the X101 spot. If it changes to all red, then the transistor is bad, and replace the transistor now at X102.

B) If the blue goes away, then your problem may be on the main chassis. Check X105 and X106 for shorts, possibly swapping them with X101 or X102 (on the main chassis). If it changes to red again, then one of those two transistors was the issue.

If none of those transistors help, then you may have another issue...
 
removed the 5 pin from the neckboard, it was still blue, though lighter blue

swapped the 2 transistors and it was still blue
 
Finished working on this the other day.

Symptoms:

1. Had a whiteish pic with retrace lines, turned brightness down pic would brighten up. Brightness knob did nothing.

2. No signal getting to neckboard

Solution

1. 2 hairline cracks around pin 9 of flyback (jumpered)

2. X303, X304 replaced bad, then missing red

3. Found solder bridge between r101&r102

Hope that helps somebody

Andrew
 
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