Astro Blaster stuck in test pattern/jail bars.

jawhn

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Picked up a Sega/Gremlin Astro Blaster yesterday, was hoping it would be an easy fix, No back door, interlock switch wired up but obviously not letting it power up, the seller said it used to work, yadda yadda yadda.

Got it cheap, so... Get it home, pull the interlock out, nothing. No marquee lights, no monitor hum, zilch.

Started checking from the plug backwards, took the interlock switch box cover off, and lo and behold, no 2A fuse in the Buss fuse holder. (Sorry, pic is sideways)

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Woohoo! So I get a 2A fuse and wire it in, and now she boots! (Thanks Brien, for the link to a similar replacement Buss fuse holder!)

...to a monitor filled with this: :( (Sorry, pic is sideways)

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(Are these officially called "Jail Bars" or "Test Pattern," or what...?)

So... Not sure what to check next. It has 5 PCB boards in 6 slots, I am wondering if there are supposed to be 6, or if any of them are in the wrong location... Need to find the manual, I guess.

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Any suggestions appreciated like crazy. Thanks in advance.
 

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Ok, the manual says the motherboard is "cross-wired," so they can be plugged in in any order, so that's not it... :(

I did inspect all of the PCBs for obvious faulty parts, like blown capacitors, chips, etc... Appeared to be just fine. What other simple things am I forgetting?
 
There is a push on the MPU board...when you push it the LED on the board will blink out a code. Could be as simple a bad Ram chip.

Dumb question... Is the MPU board the same as the CPU board??? I looked through the manual, & saw that there was a test switch on the CPU board, but didn't know the LED gave codes, I will have to check that, thanks.
 
Well, after doing some cosmetic work to it tonight, (The only thing I really know how to do...) I booted her back up again, still jail bars, (although they looked different...?) went to backside, pushed CPU test button, nothing came up on either monitor or LED, found RESET and SERVICE buttons inside coin door area, neither of which did anything... :(

Next suggestion? :confused: Is there anywhere I should be testing voltages?
 
On the bottom of the cage you will see a ten pin connector, you can check the voltages there....if you look in the manual it will show you which pin is which.

Thank you, sir! Will do. :) Sorry I'm so moronic at this, I am trying to learn how to troubleshoot/fix these things, but am starting at the bottom, for sure.
 
Ok, just got lost in the manual. :( Do I need to be looking in the schematics or something? I ran through it, looking for a drawing/diagram of that connector, but no luck...

Should I just randomly check voltages of the pins, perhaps? I'm trying to not bug Brien with this game. :rolleyes:
 
STD VIDEO

J5
-------
1 -12V
2 +12V
3 AC
4 GND
5 GND
6 GND
7 -5V
8 +5V
9 +5V
10 +5V

If you look at the connector you will see 3 black wires, those are the ground wires...pins 4,5 and 6 you can figure out the other pins from there.
 
KV: nope. :(

OM: thamkyouthankyouthankyou! Will check that later today, and report back. Getting ready to hop on the Salt River to do some tubing! :)
 
bumping this with my own Astro Blaster problem rather than making a new thread:

So the sound and speech on my AB don't work. The first thing I check was of course the volume control, and while all the wires out of the back of the knob seemed to be in place, the knob itself might be broken? Basically i can continue to turn it left or right indefinitely, like maybe something in the knob broke and it isnt actually turning the volume control?

The other thing I noticed when I opened up the back was this:

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I looked in the manual and this (J2) is the one that goes to the sound and speech boards. How should I tackle testing and/or repairing this wire?
 

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So for the picture above, where do I use the multimeter to check if that wire is actually doing what it's supposed to? I know this is a stupid question. I get stuck on the simple stuff.
 
Yes, those terms a generally used interchangably. MicroProcessor Unit, Central Processing Unit... potatoe, potahtow...

Gotcha, thanks.

I'm actually trading this game today, so don't be too surprised if another KLOVer carries the relay for me on this thread... :)
 
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