Jul 142018
 

The ‘007593’ and ‘007327’ are two custom ICs found on many PCBs manufactured by Konami in end 80s.This should be a complete list:

‘007593’ on :

  • Black Panther
  • Contra / Gryzor
  • Hyper Crash
  • City Bomber
  • Kitten Kaboodle / Nyan Nyan Panic
  • Labyrinth Runner/Trick Trap
  • Vulcan Venture / Gradius 2

‘007327’ on :

  • Combat School /Boot Camp
  • Rock ‘n Rage
  • Jackal/Top gunner
  • Flak Attack
  • Devil World / Dark Adventure
  • Double Dribble
  • Rack ‘Em Up/The Hustler
  • Haunted Castle
  • Super Contra
  • Battlantis
  • Blades of Steel

Both ICs have strong similarities starting with how they appear:

Analogous package apart, they have same function as we can see from schematics:

But the ‘007593’ and ‘007327’ are not simple RGB DAC as  you can think of at first glance but they embed a complete palette color circuitry on a single chip.So not only RAMs but, as you can see, many other ICs in form of bare dies covered by coating as well passive parts :

Therefore, for this reproduction project I used a different approach.I studied previous Konami hardware figuring out how the color palette circuit was engineered without the use of the customs.After drawed my schematics I reproduced the ‘007593’ for first:

Once successful tested,  it was the turn of the similar ‘007327’ :

Testing on their respective boards:

The layout of both reproductions could be surely optimized (with consequent reduction of the size of the board) using moderm complex programmable logics but I’m happy enough with them since my primary goal was to study a working replacement for these two custom ICs which seems quite prone to failure making our beloved PCBs unusable.

 Posted by at 12:11 pm
Jul 132018
 

Recently I decided to take a look at another custom IC, the Taito ‘PC030CM’:

It’s a 20 pin chip in a brown-ish SIL package used on some PCBs like Arkanoid, Bubble Bobble, Big Event Golf and few other.Like schematics shows, the ‘PC030CM’ handles coin inputs as well counters/lockouts:

If the part fails (most of times it breaks due its fragile nature), the board will no longer boot, an ‘I.O ERROR.’ is all you will get:

For this reproduction project I had no need to inspect or analyze the part but I simply re-engineered,using SMT devices, a replacement board that can be found on some Arkanoid bootlegs:

Then I compared my schematics to work previously done by ‘JROK’ on KLOV forums and, once verified everything, I  designed a proper PCB.Here’s the reproduction how looks fully assembled (I ordered it with red soldermask but manufacturer wrongly made it blue)

For the testing the user ‘manimani’ on Neo-Arcadia forum kindly sold me an original Arkanoid PCB :

The board was missing the ‘PC030CM’ custom :

Some workaround was made in such a way that the board could coin up the same using the SERVICE button instead :

So, this was a perfect platform test for my reproduction which worked fine:

Thanks again to ‘manimani’ and ‘JROK’.See you at my next reproduction project.

 Posted by at 10:07 am
Jul 122018
 

Received from Austria this Devastators PCB (manufactured by Konami in the distant 1988)

The board was constantly watchdogging sign that no valid code was executed :

Probing the HD63C09E main CPU revelead some address lines were dead:

I removed it :

Trying the CPU in another board confirmed it was really bad so I replaced it.The board booted up but it was failing the POST showing two bad devices which at fist glance I could not recognize due the complete lack of graphics :

Thanks to MAME I figured out they were the ones @C11 and C14 :

On PCB they are the two 2k x 8-bit static RAMs (Motorola MCM2016 used) which are part of the palette colors circuit

Probing the one @C14 revealed stuck data signals:

RAM chip failed the out-of-circuit testing:

Now the board booted into game but with severe graphics issue : the backgrounds had wrong colors and sprites were missing.Sound was absent too:

I dumped the four OTP MASK ROMs that store tiles data and found three bad ones :

But this made no real improvements.Board is almost fully populated with Fuitsu TTLs so I went to test them in-circuit with a logic comparator starting from this part of circuit which is involved in color generation  :

I found five bad mutiplexers with floating outputs:

This restored correct backgrounds:

I decided to troubleshoot for first the lack of sound.Found in rapid succession these bad ICs:

  • YM2151 (with serial data output pin stuck high)
  • sound RAM and ROM
  • two 74LS74 @G5-F10

And a 74LS273 @B7 with some floating outputs:

Sound was back :

Now the lack of sprites.MASK ROMs check reported two bad devices @H4-K4 which are the ones  storing sprites data:

This particular PCB uses a bottom ROM board with sprites and audio samples ROMs :

But the top board can also host three 4Mbit devices for the same data so you can get rid of the ROM board :

This is what I opted instead of troubleshooting it since all the splitted ROMs were soldered in.I programmed three 27C400 EPROMs with MAME dumps:

The last issue I had to fix was releated to inputs, P1 UP was not working.Using schematics I quickly found and replaced a 74LS253 @E13 with a bad ouput :

Board finally 100% fixed and another battle won against Evil Konami and Fujitsu with this big booty:

 

 Posted by at 6:14 pm
Jul 112018
 

This game had been in my collection for about 14 years. I decided to make a play but the game displayed a RAM NG text and didn’t boot

 

After checking the schematics I decided to prove rams and some devices but the signals were healthy

Thanks to Kale from mame team, I discovered that the game does a simple check but decrementing some values in ram and read them back.

Therefore I decided to desolder the program srams to check if they were good. The game has only 2x 2016 toshiba rams.

This brand is known to be not really reliable in comparison to others

After checking the first one I got confirmation that it was bad

I resoldered it and this time the game booted with RAM NG briefly shown and behaved strangely. You couldn’t shoot and parts of the scrolling was repeating.

I decided to desolder also the second one since the game still complained about the ram.

Also the second one was bad!

After changing also this one, the game was 100% fixed

 

Jul 112018
 

Got this game for a repair.

At boot it displayed the following:

Using Mame source code with the memory map I could narrow down that RAM0044Eo20 was the colour BLUE ram

Desoldering it I could confirm it was bad

After replacing it I still got:

30TIP, 31TIP and 33TIP error

After discussing with Charles MacDonald he pointed me to the DUAL PORT RAM.

It checks if the last entry in RAM (460FFF) is zero, if so that’s an error (should be non-zero)
Then it checks if 460FF contains byte 6B, if it doesn’t that’s an error too

I started to probe around the dual port ram

Until I found a stuck bit on the Left side of the Dual port ram which came from a 74HC175.

After changing it, the game booted but still with TIP33 error which could be erased by pushing the start button.

TIP33 is the error related to the EEPROM which is not inizialized correctly or contain some corrupted data. Normally you inizialize it only one time but everytime

started the pcb, I got this error and offcourse all the dipswitch settings couldn’t be saved correctly.

To cut a long story short, some smart guy changed the original EEPROM with a normal 8k SRAM!

I took a spare from a faulty final lap 3  and I could finally fix 100% the game