CHICKEN RESTORE LIKE A ROBOT (Berzerk) *IT LIVES*

[ChadTower]

Damn, just hours after swapping those connectors, I finally find the right one thanks to KeyLayton.

For future reference, Stern used the Commercial AMP Mate N Locks:



Mouser part # 571-14802750, manufacturer part # 1-480275-0

[ChadTower]

W00t!

Wired up a matching 15" harness for the CP... connected that to the IPAC4... works exactly as it should.  I'll get some pics up shortly.  I only wish I had the right color wires to match the CP harness, all I had was a lot of black, but this will have to do.  I'm taking the CP apart now to clean everything up.  The buttons may have to be replaced just because they're so beaten up.

The cool part about this configuration is that when I get the boards fixed I can just take the Ipac out and reconnect the main cab harness without hassle.   

Ipac to CP wire harness - the black wires

[ChadTower]

Last night and this morning took the CP apart and gave it a good cleaning.  Buttons scrubbed, joystick dismantled and cleaned, carriage bolts got the Dremel wire wheel.  The CP appears to have been clearcoated at some point in the past - not sure if it came from the factory like that or if someone did that to try and save cracking paint.  The clearcoat is now cracked since I don't think it was supposed to be used on metal.  Overall it is probably better off for having had the clearcoat than it otherwise would have been.  Buttons came out a little better than expected.  I'll still replace them eventually but it's no hurry.  The right fire switch was pretty grungy and had not been working until cleaned.

Dirty CP w/buttons removed

Clean CP - full working setup on bench

[ChadTower]

I had been experiencing intermittent boot failures... it would get to a certain point, showing a MAME splash screen, and then just freeze.  A ctrl-alt-del brought me back to the cmdline with what appeared to be a C floating point error.  No way that should be happening intermittently.  Then I noticed that the OS wasn't keeping the time.  It was always 1980 in this machine.  That usually means a dead motherboard battery.   This mobo takes a CR2032 which miraculously I had a couple on hand because the Sega Saturn also uses them.

Replaced that and it appears that about 5 odd errors I had occasionally been getting went away.  Let's hope it stays that way.   

[ChadTower]

Installed arcmon.sys, hooked it up to the cab monitor via the VGA cable I hacked... no dice.  Scrambled screen even after full boot.  No adjustments bring it into sync.  Maybe my cable hack is wrong but I'm not sure at this point how to verify that.

[ChadTower]

So... I made my breakout cable based on this:

1 - Red
2 - Green
3 - Blue
4 - Monitor ID *
5 - Ground
6 - Red Ground
7 - Green Ground
8 - Blue Ground
9 - Keyway (No pin)
10 - Sync Ground
11 - Monitor ID *
12 - Monitor ID *
13 - Horizontal Sync
14 - Verical Sync
15 - Monitor ID *

You can ignore all the pins marked *, as we won't be using them. Don't forget to wire in all the grounds, wire the first one to Video Ground on the JAMMA fingerboard, then solder a short wire from this across to one of the Ground pins on the fingerboard. This just makes sure all your grounds are common.

As for getting composite sync from separate horizontal and vertical sync (which is what VGA puts out), you should run them through and XOR gate (7486) but I cheat - and just twist the wires together.

Now that I see it's not working for me, I think it may be that this JAMMA scheme isn't going to work for me in this case.

Looking at the monitor schematic I see this from the input connector:



My problem appears to be incorrect sync.  The instructions I followed say to combine sync lines... but the monitor schematic has separate inputs for negative vert, negative hori, positive hori, and positive verti.  Nothing for composite sync.  What I have to do, I guess, is figure out which are coming from this video card and then make a new cable. 

[ChadTower]

Also, the joystick has a ton of play in it.  Makes precise control difficult at times.  It's a Wico 8 way... the fix for that is what, a new grommet?

[SirPeale]

Also, the joystick has a ton of play in it.  Makes precise control difficult at times.  It's a Wico 8 way... the fix for that is what, a new grommet?

Yes.

What monitor do you have again?

[ChadTower]

What monitor do you have again?

K7000, if I have it right from the chassic pic archive.  19".

[ChadTower]

Here is a very useful page on troubleshooting VGA to RGB connection problems.

[ChadTower]

Okay I just tried pretty much all combinations of sync with jumpers and nothing worked.  This is ticking me off.

[ChadTower]

A useful VGA - arcade monitor tutorial pointed to me by Peale.

[ChadTower]

So I tried it again tonight... and with some adjustment got to a scrolling double screen with DOS on it.  That sounds much like what Peale described to me as not booting to 15khz... so on a whim I swapped at the video card connector to a PC monitor and boom it looks good.  So somehow I'm not loading properly to 15khz.  Progress, I suppose.

For some reason, not 15khz

[ChadTower]

Oh, funky.  I just loaded mame on the PC monitor... then exited, and the screen went wacky.  So I plugged in the arcade monitor and now I get a dos prompt.  A weak signal, but it's a dos prompt clearly on the Berzerk.  I have no idea why it only went to 15khz after I loaded and then exited mame.

Then, I load Frenzy, and it goes back to 60khz... I exit to the prompt, back to 15khz.  And if I load Berzerk it's just a black screen.  Isn't arcmon.sys supposed to keep the whole session in 15khz?

[ChadTower]

This is definitely a freakin' dos issue now.  First line of config.sys:

DEVICE=c:\dos\arcmon.sys

For some reason, it doesn't load that on boot.  It boots regularly, then I go to c:\mame and start MAME.  It runs MAME in 60khz, as it should... then if I exit back to the prompt it goes to 15khz.  A restart of MAME from 15khz starts mame in 60khz... and exiting back to the prompt gets it to 15khz again.

 

I wonder if this has anything to do with the MAME boot screen that spystyle's CD installed.  I don't know exactly where that is gettin called so I'll have to figure that out.

[ChadTower]

So, I stuck a couple pause commands in autoexec.bat so I could get a better look at the boot sequence.  Near the beginning of the dos driver loads I see:

Code: [Select]

============================
  Arcade Monitor Driver v1.0 Loaded
------------------------------------
     Horizontal Total     : 105
     Vertical Total        : 4
     Center X              : 8
     Center Y              : 8
============================

So, for whatever reason, it seems to be loading and then unloading?  And then reloading when I exit MAME back to the command prompt... only to exit again when I launch MAME.  WTF...

[SirPeale]

post both your autoexec.bat and config.sys files.

arcmon.sys is a TSR, it *should* stay in memory. 

When you load Mame, did you turn the arcade monitor flag on?

[ChadTower]

post both your autoexec.bat and config.sys files.

arcmon.sys is a TSR, it *should* stay in memory.

I'll do that tonight.
 

When you load Mame, did you turn the arcade monitor flag on?

Possibly not.  I'll check the readme for which key that is in mame.cfg.  Thanks for the tip.

[ChadTower]

Well, here's one part of the likely solution.  DOSMame config item:

Code: [Select]

-monitor NNNN (default: standard)
              Selects the monitor type:
              standard: standard PC monitor
              ntsc:     NTSC monitor
              pal:      PAL monitor
              arcade:   arcade monitor
I haven't changed that from the default.  So that would explain why Mame is not running in 15khz.  It doesn't explain, though, why the TSR is not staying resident at initial boot.  I'm not booting straight to the front end yet, just to the DOS prompt.

[ChadTower]

Setting -monitor to arcade does the trick nicely... except that now Berzerk won't run at all.  Frenzy pops up on the screen nicely in 15khz... monitor needs some adjusting but it's fairly close as is.  When I try to run Berzerk, though, I get the "press any key" screen, then the expected screen flashes as Berzerk "boots"... and then nothing.  The screen stays black.  I tried re-copying in the rom zip, I deleted the .cfg and the nvram files... no difference. 

 

[ChadTower]

Deleted all berzerk derived objects, got the roms from mame 0.37, copied in the samples again, and now berzerk works.  Not sure why before.  Front end still not booting to 15khz... will try arcadeOS.

[ChadTower]

With some tweaking and a couple tips from Peale, got ArcadeOS running in 15khz too.  Now to tweak it for max performance, give it a little customization, and then get the sound working with the cab speaker.  I'm going to poke around and see if I have any spare speakers of this size to swap in, too, since this one is a 30 year old paper thin cone.

Also ordered a couple Wico stick grommets and some new shafts, though those shafts will probably end up on other games.

[SirPeale]

You can use some wire taps to get sound working pretty easily.  Just wire a 1/8" jack with your wires, and use the taps to splice it in.  When you fix the berzerk you can just remove the taps.

[ChadTower]

I'll probably just solder onto the speaker tabs.  Takes two seconds and won't cause conflict because I don't know that I'll ever run both the game PCBs and the MAME PC at the same time.

Man, I googled wire taps because I don't know exactly what they look like, and I think now I'm on the Homeland Security watch list.

[seinologist]

How's this project going? Did you get the boards repaired?

I sold 2 sets of Berzerk boards on ebay this past summer and they went rather quick @ $175.

Any acid damage on the zpu?

[ChadTower]

Very minor acid corrosion... nothing worth worrying about, though.  All traces intact and no PCB enamel loss.  Worst case is a few components need replacing because the battery outgassing got to the legs.

I've been trying to find someone to do the boards but it seems all of the local repair people don't answer emails now.  It's a bit odd.

Got sidetracked with remodeling part of my bathroom, but now that that is nearly finished, I can get back to this project soon.

[ChadTower]

Had some long overdue time off last week so I got back to this a bit.  I decided to push the MAME config aside for the time being and get back to the boardset.

With a little guidance from a friend I managed to get the likely problem narrowed down.  Did some reflow work and got the voltages back to proper ranges on all boards.  Still no test flashes and garbage on the screen.    Was advised to pull power from everything except the ZPU and a good ZPU alone should get the first three test flashes.  Still nothing.  Then was advised that the typical battery acid fallout zone is the z80's reset circuit.  It did have some damage, not a ton, but whoever had it before me that took out the battery did leave some there.  Cleaned up the rest of that, scraped off some residue, spent a lot of time with alcohol and Q tips, reflowing/cleaning, and still no change.  At this point I was advised to check the reset pin on the z80 - which should be persistently high (around 4.5-5v).  It's near zero so there is the problem.  Next up is to trace the reset circuit back and find the problem, either an acid tweaked component or a bad trace.  I don't see any likely bad traces so my guess is a pad that still needs to be redone or a dead transistor.

Of course, part of the way in, my old Weller station developed a major fault.  I pulled the iron from the stand and it was glowing red from the tip to halfway down the iron shaft.  My backup station is a 20/40 watt $20 model... 20 watts isn't hot enough and 40 is too close to trace lifting.  So I need to pick up a new station when some money frees up.

[javeryh]

I just watched Chasing Ghosts last night and the two guys couldn't get their Berzerk working - hopefully you have better luck than they did!

[froggerman]

Of course, part of the way in, my old Weller station developed a major fault.  I pulled the iron from the stand and it was glowing red from the tip to halfway down the iron shaft.  My backup station is a 20/40 watt $20 model... 20 watts isn't hot enough and 40 is too close to trace lifting.  So I need to pick up a new station when some money frees up.

Is this a WTCPN type of Weller station? If that is the case, it is probably the element that is bad. This can be fixed inexpensively. What happens is that the tip stilcks to the heating element and the heat stays on 100% of the time. I have changed mine twice over the last 20 years...it is still working great.

Anyway, have a look.

[ChadTower]

WTCPS, actually... so you're saying it could be a bad element even though it's still heating?  How could I tell a bad one?  I did take it apart and saw nothing failed looking.

[menace]

Very neat! another fav of mine as well (even though I mamed the last one  )  Anyways, there is a guy on www.cgcc.ca named wyswig that is great with board repairs--if you run into dead ends I'm sure he could help you. 

Also regarding the bezel--there does not exist a decent one yet that I know of.  Someone was going to vector from a scan and got sidetracked then sidetracked again and here we are years later with no bezel repro done (and no scan cause it wasn't released either).  If nothing else, scan yours into rough and dump it to the artwork site so others can vector it if they want.

just a thought...

[froggerman]

WTCPS, actually... so you're saying it could be a bad element even though it's still heating?  How could I tell a bad one?  I did take it apart and saw nothing failed looking.

Hi Chad,

I just had a look at the exploded parts diagram and it would be more likely that it is the switch inside that has failed. This makes sense if your problem is that the iron is too hot. Have a look at this illustration and the instructions for replacing switch SW60. 

http://www.action-electronics.com/pdf/wtcpstechsheet.pdf

Those Weller irons are made for a lifetime of use and parts are pretty easy to find. You can even buy a whole new pencil if you want, and that is much less expensive than the whole station.

I know that the WTCPS is quieter than my WTCPN but you should still be able to hear the switch click on and off while the iron is in operation. I would assume that yours is not making this sound at the moment.

[ChadTower]

Thanks for the advice... I found a couple web pages on this and you're right, it's likely the switch. I'll check that soon.  In the meantime I found someone selling a temp controlled WES that has barely any use on it for a very low price.  So that should be here in a couple of days.  Worst case scenario here is that I end up with a working WTCPS and a new WES.  What a crime that would be!   

I have never actually heard the old one click.  I definitely understand the concept of the Curie Point style iron now but it's odd that this one has been so silent. 

[ChadTower]

Took it apart again last night and found the spring... definitely old and a bit rusty.  I cleaned it all up a bit and turned the iron on for about 15 minutes.  It seemed to hold temp properly (though really how can you tell visually other than the tip).  So maybe the switch was just jammed.  I didn't get a visual on the switch because I'd have had to start clipping wires to get that far into it.  Once the new one shows up I'll end up with three stations - I definitely won't want the 20/40 station so maybe I'll give that sucker away as a contest prize or something.

[slasherman]

I just watched Chasing Ghosts last night and the two guys couldn't get their Berzerk working - hopefully you have better luck than they did!

 

[ChadTower]

Duh!  It won't work because that's a Track and Field PCB!

[froggerman]

Thanks for the advice... I found a couple web pages on this and you're right, it's likely the switch. I'll check that soon.  In the meantime I found someone selling a temp controlled WES that has barely any use on it for a very low price.  So that should be here in a couple of days.  Worst case scenario here is that I end up with a working WTCPS and a new WES.  What a crime that would be!   

I have never actually heard the old one click.  I definitely understand the concept of the Curie Point style iron now but it's odd that this one has been so silent. 

That sounds like a great deal. I have both a WTCPN and a WTCPS and the WTCPN is very easy to hear, the WTCPS is very quiet.

[ChadTower]

So far, the new station is great, but the tip it came with needs replacing.  I've cleaned it 20 times and it's just not staying tinned.  The end of the tip doesn't melt solder for a good 8-10 seconds even at 725.  I'll have to order a couple different types while I'm doing it.

Started tracing the reset circuit.  Replaced the first cap, checked a few of the resistors.  Other than being really dirty they all checked out and were cleaned.  I'm having trouble getting the transistors out because of all the oxidation so I may have to make up a list and just start swapping them with new ones.

[ChadTower]

Saturday made up a list of all the diodes and transistors in the reset circuit.  Went over to You Do It and picked up 30 2N3904s and a massive diode variety pack that had 50 of the zener type I need.  Seems as though unit price is like $1.80 for a single or $5 for 30... sorta frustrating for parts that don't have a bulk pack.  Also picked up a variety of tips for the WES50. 

Tonight cut out Q1 and Q2.  Clipped Q2 too short to test but Q1 tested strange.  Put in new ones that tested good, plugged the board back in because of Q1 bad test, and BAM three beeps!  That's exactly what I should expect from a ZPU alone.  Plugged everything else back in and four beeps.  So I'll look that up tomorrow and see where to look from there.

[ChadTower]

Oops!  RAM board was still unplugged... which is the fourth self test.  Plugged that sucker back and it's in attract mode now.

 

I still have to adjust the monitor back from MAME land and do some burn testing but for now Berzerk is back!