Bogey Manor repair log

Got always from Austria for repair a rare Bogey Manor PCB.It's an oscure game released by Technos in 1985 :

As said, the board was faulty as graphics was totally scrambled, sometimes you could only see some sprites:

Although released by Technos actually the game runs on Data East hardware which has similarities with other 8 bit games from same manufacturer as MAME source suggests:

Data East 8 bit games

This hardware uses some custom ICs:

The ones marked 'HMC20' (DIP28 package) and 'TC15G032AY' (PGA135 package) seem to be involved in clock dividing and sprites generation while the 'VSC30' (DIP40) appeared to be related in some way to the tilemap/backgrounds.After some check I found nothing abnormal on the rest of the board hence I was quite sure one of these custom IC was faulty.Since the issue concerned the background graphics I focused on the 'VSC30' :

I found its pinout on the Express Raider schematics :

Probing the outputs revealed they were mostly stuck HIGH :

I piggybacked a good chip and got all the graphics back (although not correctly displayed due to not perfect piggybacking) 

This lead me to remove the part and replace it with a spare taken from a donor board :

In this way graphics were completely restored.At this point, as always I do, I launched the game under MAME and did some comparison to see if everything was correct.I immediately noticed some music tracks were missing on my board :

Here how it should be from a MAME recording :

Sound is generated by a couple of AY-3-8910 :

Swapping them with good ones revealed one was bad.Replacing it restored full sound and fixed board completely.The two culprits in the dock :

Another repair successfully completed.

P.S.

It seems this board, along with other ones from Data East of same era, the image is upside down from factory and no dipswitch is present to flip the screen.

Rush & Crash repair log

Received from Austria some faulty PCBs for repair.I started my job from an original Rush & Crash (the japanese release of The Speed Rumbler), a shooting game released  by Capcom in 1986.

PCB is a two stack one with a top board (where main and sound CPU circuits lie) :

And a bottom one :

The fault concerned the graphics as backrounds were totally missing/wrong or disappearing :

All the graphics is generated on video bottom board so I focused on this one.Many Fujitsu TTLs drawn my attention hence I went through them with my HP10529A logic comparator.Quickly I found a 74LS74 @7D with two suspicious bad outputs :

 

I removed the IC .

Chip failed the out-of-circuit testing :

Fitted a good IC :

This restored the backgrounds but playing some games I noticed the sprites were slightly glitched by some tiny lines through them :

 

The sprites circuit lies on bottom board, data are stored in eight 27256 OTP ROMs and then sent to two custom ICs marked '86S100' (which is basically a shifter) 

I made a reproduction of this custom chip time ago (actually I made two versions because the original part can work in two different modes)

Capcom '86S100' reproduction

Hence I know how it works and where to check for its proper functionality.Probing the two '86S100' revealed a lack of data on an output of the one @13E, you can see how the signal of the below left picture has less transitions than the one on the right:

I removed the IC and installed a repro of mine :

This fixed the sprite issue :

Board 100% working and another repair accomplished.

Sega '315-5011' reproduction

Some time ago I have done a reproduction of the Sega '315-5012' custom IC, the sprite generator used on System1/2 and other unique Sega hardware :

Sega '315-5012' reproduction

Since this custom IC is always used in pair with its "companion" '315-5011' I thought it would have been good to have a reproduction of this too.And here we go!

The Sega '315-5011' comes in a 600 mil DIP40 package :

It accomplishes graphical functions being a sprites line comparator as we can read in some hardware overview found online.As I did for the '315-5012', I extrapolated the equivalent circuit from a piggyback board found on some bootlegs.Since I used thru-hole devices for this first prototype, the resulting board layout is not particularly neat and compact :

But I was mainly interested in functionality to be sure the drawn schematics were good because it's quite easy to do a mistake when you are tracing hundreds of connections.The final test proved that no mistakes had been made, the prototype worked fine :

Sega '315-5011' and '315-5012' now again together, both reproduced to preserve more and more boards!

Seibu 'SEI0050BU' reproduction

Reproductions, reproductions and always more reproductions!
You know, reproducing old hardware, especially custom one, is vital for preservation purpose and it doesn't really matter if the part taken into accout is not often seen on arcade PCBs.Perhaps it's the case of the 'SEI0050BU', a custom IC found on some Seibu PCBs like Toki, Cabal, Raiden (some hardware revisions) and few other.

The IC comes in a 600 mil SDIP40 package :

There is no official documentation or schematics/pinout about this custom IC (except for some mention in MAME source) hence for first I figured out the direction of each pin.Then, as always I do, I studied how its functions were reversed on bootleg boards with the use of simple logic gates.The resulting schematics drawn gave me the equivalent circuit that was then routed to a proper board.For a first "quick & dirty" prototype I chose simple thru-hole parts, there is no point using SMD or complex programmable logic devices if you first of all didn't validate the design :

Not the neatest and smallest layout perhaps but the prototype worked fine.Here is test on Toki and Cabal PCBs :

We now have a solution to replace faulty 'SEI0050BU' custom ICs and save more boards from uselessness.