Caius

Toaplan (Vimana – Out Zone) double repair log

PCB Repair Logs Comments Off

Jul 222018

I’ve been sent from Portugal a box of faulty PCBs for repair with some Toaplan stuff inside like Vimana and Out Zone (both japanese revision)

Vimana :

Board was booting and played fine except for some little glitches on background:

Backgrounds data are stored in four 28 pin 1Mbit MASK ROMs:

Devices were dumped fine except the one @ROM3 which gave inconsistent readings.Loading the file into MAME emulator reproduced the issue exactly:

I replaced the faulty MASK rom with a 32 pin 1Mbit non-JEDEC EPROM (adding the missing sockets)

Board 100% fixed:

Out Zone :

Board booted but sprites were garbled :

Probing a row of RAMs revealed /CE pins on three of them (the two 6264 @13A-14A and the 6116 @16A) were receiving no signals :

At a closer inspection I found a burnt trace going under them:

I removed two of the three involved RAMs:

Tracing back the burnt trace I figured out it was a GROUND signal that should have been daisy-chained to the /CE lines (grounding also address lines A10-A9-A8 of the 6116) of the three RAMs enabling the chips.A couple of jumper wires did the job:

Konami ‘054574’ reproduction

Reproductions Comments Off

Jul 202018

The ‘Konami 054574’ can be found on some PCBs from this japanese manufacturer always along with the three RGB DACs ‘054573’ (see past article for this ) so this reproduction is the natural follow up.

It shares the same SIL package and pin counting :

As well as most of the internal circuitry with open collector buffers, R/2R and transistors:

Its functions are not really clear though, for sure it’s connected to the above mentioned ‘054573’ and the ‘054338’ (which is a color mixer for special effects) so possibly it’s a RGB mixer/filter.

I simply reproduced it at ‘low-level’ identifying all the parts with their values and figured out the circuit schematics.Here’s the result .

Testing was successfully carried out on a Wild West C.O.W.Boys of Moo Mesa PCB :

Konami ‘007593’ & ‘007327’ reproduction

Reproductions Comments Off

Jul 142018

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

‘007593’ on :

Black Panther
Fast Lane
Contra / Gryzor
Hyper Crash
Salamander/Life Force
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
Ajax
MX5000

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.

Taito ‘PC030CM’ reproduction

Reproductions 2 Responses »

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, Tokio/Scramble Formation, Legend of Kage 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.

Devastators repair log

PCB Repair Logs 3 Responses »

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:

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