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Manufacturer: Atari
Year Released: 1982
PCB Function: CPU
Part Number: A038575-21
Stack Type: Single Board
Stack Part Number:
Dimensions: Unknown
Contributed by: ieure
Description:
The are two versions from Atari and one version from Namco.  The two pictures here are the Atari Versions.  Each board has a distinctive layout.
 
When looking on http://arcarc.xmission.com/ for the RAM and ROM failures you'll need to figure out which PCB you have and match it either to Type "A" or Type "B".  This will give you the physical location of the RAM/ROM chip that is reported as bad.
 
For example, a bad RAM of 3L is physically located at 9H/J on a Type "A" board and 7L on a Type "B" board.
Type "B"
PCB Connectors:
Connector Number 
Connector Label 
Pin Count 
Connector Position 
Primary Connector 
 
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PCB Parts:
# 
Part Name 
Part Description 
Part Number 
Mfg Part Number 
Location 
Group 
Section 
Socketed 
  
xv
 
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PCBs for this game:
Part Number 
Description 
Stack Part Number 
Pcb Function 
Contributor 
A038575-21
The are two versions from Atari and one version from Namco.  The two pictures here are the Atari Versions.  Each board has a distinctive layout.
 
When looking on http://arcarc.xmission.com/ for the RAM and ROM failures you'll need to figure out which PCB you have and match it either to Type "A" or Type "B".  This will give you the physical location of the RAM/ROM chip that is reported as bad.
 
For example, a bad RAM of 3L is physically located at 9H/J on a Type "A" board and 7L on a Type "B" board.
 CPUieure
A035435   PowerSupplyArcadenut
This PCB can also be used with the following Games:
Game 
Manufacturer 
Year Released 
Notes 
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Repair logs for this PCB:
Title 
Symptom 
Solution 
Status 
Scrambled video, ROM issues Powers up to scrambled video and watchdogs.
Game appears to be booting, but video output is non-functional. Probing /CSYNC shows it stuck low. Tracing sync back from the test lug, found a broken leg on R86. Fixed, but still no video.
 
/CSYNC originates at LS368 @4E, with /CMPSYNC output on pin 3 and input coming from pin 2. Continuity from the sync pin to 4E's output was good, so started probing with a scope. Signal on /VSYNC and /HSYNC test lugs looked good, but output on 4E was not correct — H sync was present, but there was no V sync added.
 
Per the schematic, input to 4E comes from a LS00 @6H, LS74 @6C, and LS86 @4A. 4A is not populated on this PCB, and 6C's outputs connect directly to 4E's inputs. 4A is driven by /VSYNC and the 4V line from the 07xx custom @4C. Both these inputs appear good, but output lacks V sync, so the LS74 is suspect. Comparing in-circuit against known good part with a logic comparitor confirms a fault. Socketed and replaced the part, and video is now present.
 
While there is video, the board is watchdogging. It gets through most of the power-on tests, prints "RAM OK," and resets, which is a good indication that there is a ROM problem. Put it on the Fluke and ran ROM tests, which returned the correct signatures, but at the wrong locations. Visual comparison against another board showed that the -205 and -206 ROMs had been installed in the wrong sockets. Swapped them into the correct locations, and the board boots and plays.
Fixed
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