The NEW Build Your Own Arcade Controls
Arcade Collecting => Miscellaneous Arcade Talk => Topic started by: Kateann on July 07, 2017, 01:16:51 pm
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Hi everybody,
This is my first post to here, so a quick "more about ourselves": we live in Belgium, Europe, born on the golden age of videogames and yes, I am a woman.
We have an old Dig Dug arcade with a PCB-issue: self test seems ok, but after that, the attract mode starts without the characters. So you can play the arcade game, but without the little fella.
Any thoughts what might cause the problem? Thank you!
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Do you have access to the schematics for the machine? I would carefully take out the EEPROMs, clean the legs, and reset them first.
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Rather that start tearing things apart, Jennifer (not just a woman, but a princess of some faraway land ::)) would set up a mirror so you can see the screen from the back, and then lightly tape on the chip with a freshly manicuered fingernail , a "dirty chip will momentarily flicker back to life isolating the problem on a working game.... More than likely my guess would be the sticker feel off the EEPROM window corrupting the data given the age of that machine.
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Thank you Yotsuya and Jennifer.
The advice of a princess of some faraway land cannot be denied. :D
Not sure what you mean by "lightly TAPE on the chip". Just a quick gently "tick" with a finger. Like CPR to the EEPROM? Bring it back to life like that?
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No schematics here with me at the moment, so I need to find the EEPROM that's messing with the gameplay.
I know I have a TYPE B PCB.
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I am all new to the tech stuff on arcade games, so please be gentle and patient with me. The online information is overwhelming. Thank you! :)
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No schematics here with me at the moment, so I need to find the EEPROM that's messing with the gameplay.
I know I have a TYPE B PCB.
An Owner's Manual with schematics is here (http://www.arcade-museum.com/manuals-videogames/D/DigDug.pdf).
Look on pg. 50 to see if the component layout is the same as your PCB.
That page also has the reference grid for finding components on the PCB.
For example:
- Upper right of page 87 you'll find a rectangle labeled "4D LS377"
- On page 50 where "4" and "D" cross, you'll find the LS377 IC just below the circle labeled "SW1 Reset".
- The notch on the IC (bottom edge, next to the L) shows the location of pin 1
-- If the notch is up, pin 1 is in the upper left (see pg 1 diagram upper right here (http://www.ti.com/lit/ds/symlink/sn74ls377.pdf))
-- The rest of the pin numbers run counter-clockwise around the IC
Not sure what you mean by "lightly TAPE on the chip". Just a quick gently "tick" with a finger. Like CPR to the EEPROM?
CPR to the EEPROM. :duckhunt
I'm sure Jennifer meant to write "TAP".
Scott
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Tape = tap.... (Sooo very embarrassed) :-\
Dirty little secret on boards is unless you have considerable experience and equipment making them worse is far easier than fixing them and at that point no one (with any level of credibility) will touch them .... Normally Jenn doesn't promote outsourcing , but these guys are really good http://eldoradogames.com/ (http://eldoradogames.com/) .... Might want to talk to them first before you touch anything.
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So no "tapping" then, Jennifer? :-)
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Thank you, Scott!
How do I know which of the EEPROM is corrupt?
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How do I know which of the EEPROM is corrupt?
Since you mention above that graphics sprites are missing it would probably be one of these graphics (gfx_) PROMs listed in an excerpt from the MAME XML (http://www.gamesdatabase.org/mame-rom/digdug) file:
Name Size
dd1.9 0002048 gfx1
dd1.15 0004096 gfx2
dd1.14 0004096 gfx2
dd1.13 0004096 gfx2
dd1.12 0004096 gfx2
dd1.11 0004096 gfx3
dd1.10b 0004096 gfx4
Hopefully you can directly relate these names to the socketed and labeled ICs on your board.
If not, you can use the info here (http://www.solvalou.com/subpage/arcade_roms/D/digdugb) to cross-reference to other names.
For example:
- On that page, "dd1.9" (gfx1) also crosses to "136007.108" (gfx1)
- You can find P/N "136007-108" halfway down page 52 of the Dig Dug manual (http://www.arcade-museum.com/manuals-videogames/D/DigDug.pdf)
- The location for P/N "136007-108" is the "(8R)" after the part description "Programmable Read-Only Memory"
- Look at grid coordinates 8R on the diagram on page 50 to find the related IC on your board.
Scott
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*Jennifer slowly eats popcorn all wide eyed* :o.... Dude you ARE fun! its quite refreshing to see someone who isn't afraid of the answers, that's only half the story however, after finding a problem like that fixing it becomes issue, practicing on none working boards and dumping the roms is how I started, But that's because I have never fully trusted the data on Mame roms.... Needless to say that requires a workbench that your average Utuber wouldn't invest in to fix one board.
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*Jennifer slowly eats popcorn all wide eyed* :o.... Dude you ARE fun!
You say that like there is someone that questions it. :P :lol
its quite refreshing to see someone who isn't afraid of the answers, that's only half the story however, after finding a problem like that fixing it becomes issue, practicing on none working boards and dumping the roms is how I started, But that's because I have never fully trusted the data on Mame roms.... Needless to say that requires a workbench that your average Utuber wouldn't invest in to fix one board.
Your earlier recommendation of outsourcing the repair is definitely a good suggestion, but it probably wouldn't hurt to figure out which PROMs are the likely culprits, inspect them closely for physical damage, gently tap on them, and maybe even *very carefully* reseat them if she feels comfortable doing that before taking the chance that the board gets damaged in shipping.
By narrowing things down to the most likely PROMs, OP is less likely to mess with something unrelated to the current fault and accidently cause another problem.
Scott
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I've taken a closer look at the PCB and noticed the first edge connector pin (where it says A) is a bit crispy. Too much power going in? Can this affect the graphic sprites?
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(http://wp1020422.server-he.de/vintage/web-content/upload/open/Arcade/Atari%20Dig%20Dug/DSC00356.jpg)
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(http://wp1020422.server-he.de/vintage/web-content/upload/open/Arcade/Atari%20Dig%20Dug/DSC00025.jpg)
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(http://wp1020422.server-he.de/vintage/web-content/upload/open/Arcade/Atari%20Dig%20Dug/DSC00026.jpg)
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(http://wp1020422.server-he.de/vintage/web-content/upload/open/Arcade/Atari%20Dig%20Dug/DSC00027.jpg)
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The manual I linked to earlier is for a different version of the board. :embarassed:
This copy (http://www.arcade-museum.com/manuals-videogames/D/dig-dug-pcb-type-b.pdf) has the correct layout information for your Atari type B board.
I've taken a closer look at the PCB and noticed the first edge connector pin (where it says A) is a bit crispy. Too much power going in? Can this affect the graphic sprites?
On page 4, upper left of the schematic package (http://www.arcade-museum.com/manuals-videogames/D/digdugsp.pdf), you can see that pin A is a 5v return line on J20/P20. (Jack 20/Plug 20)
The crispyness appears to be a sign of too much current flow and/or a poor (higher than normal resistance) connection.
A higher resistance connection will convert more power to heat, that speeds corrosion, that increases resistance, that converts more power to heat, . . . until it ends up like this or worse.
(http://forum.arcadecontrols.com/index.php?action=dlattach;topic=136713.0;attach=302824;image)
To verify if you have a poor connection at pin A instead of just an ugly-looking but functional repair, you could use a multimeter to test the resistance between the top leg of R132 (slightly down and left from pin A in your pic) and P7 pin 1. (where the other end of the wire connects to the "Regulator Audio II" board)
As always, make sure no power is applied when measuring resistance -- unless you want an excuse to buy a new meter. >:D
A reading of less than 2 ohms should be good enough.
A higher resistance connection needs to be fixed by someone who can properly repair/replace the crispy trace on the PCB.
- Anyone who can do the trace repair can also chase down what is causing your missing sprites.
- You may also need to replace Pin A in the P20 connector if it was damaged/corroded by the heat.
Scott
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Thank you Scott!
I will not send the pcb out for repair just now. It might cost me a lot more than just buying a new one, so I want to try and learn about it as much as I can.
Unplug the game, remove the connector and take the pcb out for closer inspection seems like a good idea.
This might be a very dumb question, but can I just put in a TYPE A Dig Dug pcb? I cannot seem to find any info on that? This is a TYPE B. Thanks for the correct layout!
Any thoughts about the (long) red jumper wire?
Ann
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can I just put in a TYPE A Dig Dug pcb? I cannot seem to find any info on that? This is a TYPE B. Thanks for the correct layout!
On closer examination, all of the schematic links above are for a Type A board. (P/N A038156-01) :embarassed:
I can't find schematics for the Type B board (P/N A038575-21) -- closest I can find is this (http://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Dig_Dug/Dig_Dug_TM-203_4th_Printing.pdf) TM-203 Manual, 4th Printing that shows the Type B board. (3rd printing and earlier showed the Type A board)
This lack of Type B schematics hints that there is a pretty good chance that even though the layouts are different, the schematic/pinout might be the same.
To verify that, chase the individual wires of P20 from the Type A schematic on pg 62 here (http://www.arcade-museum.com/manuals-videogames/D/DigDug.pdf) and/or this (https://www.arcade-museum.com/pinouts-game/7581.html) pinout listing and see if they go to the same places in your Type B cab.
i.e. The "W/GN" (white/green) wire from pin 11 of P20 goes through pin 5 of P24 to pin 5 of J24 (wire color changes to "GN" green) and on to both of the "Pump" buttons)
Any thoughts about the (long) red jumper wire?
Other pics of Type B boards don't show it.
It isn't the "4 credits for 1 coin" mod mentioned on pg 4 of this (http://pinballpirate.com/wp-content/uploads/2014/07/Atari-Coin-Collection-newsletter-V6N7-SepOct1982.pdf) newsletter and in this (http://arcarc.xmission.com/PDF_Arcade_Atari_Kee/Dig_Dug/Dig_Dug_Bulletin_Credit_Problem_(July-30-1982).pdf) Field Service Bulletin.
It was probably installed in parallel with a damaged/broken trace by the same person who did the "ugly repair" on the trace leading to Pin A. :dunno
Scott
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I wouldn't over complicate things. I'm hundred precept sure that it is the same pinout. Otherwise, they'd have to issue a brand-new wiring harness if you changed the board, and nobody wants to do that.
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The jumper wire is between C65 and C42.
Not sure what is going on.
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Hi all, it has been a while, but I have been busy with our Cosmic Alien and Ms. Pac Man.
Today, I started to take another look at the Dig Dug. I located the PROMS and will check them out in the next couple of days.
But I was wondering: would it be a good idea to acquire another PCB on Ebay and if tapping or cleaning the legs doesn't work, just replace the GFX PROMS? Or is that asking for trouble?
I do not have a logic probe or work bench yet. So if you can help me set that up, that would be great. I do not find direct and good instructions. I'm familiar with digital logic, a bit. :-)
Thanks for you help and input!