Jun 252016
 

Dug this board out today with the view of selling it.
I put it on to test and also fired up MAME for a comparison and noticed that the digital samples weren’t playing at all. It first noticeable on the attract sequence when the lightning strike and you should be able to hear thunder.
This game uses an M6295 chip in order to deal with the samples so it was really easy to make a start trouble shooting. Using the scope I could see all the inputs and outputs were toggling when I would expect and could see one of the enable lines going active when the thunder sample was meant to play but the DAO pin (pin 36) was just dead. I did try to reflow this just in case but it made no difference.
I replaced this with one from a scrap PCB
20160625_190328
20160625_193803

Sounds are all back now

 Posted by at 8:00 pm
Jun 232016
 

Got Muddymusic’s Helifire (not to be confused with Hellfire by Toaplan) to look at.
He bought the original cocktail cab and on first power up was met with nothing but a “loud noise”.
His initial checks were that his +5v line was reading +2.5v and sent me the PSU to work on.
Now due to the various AC voltages required to actually use the PSU I was unable to do any real testing so instead he sent me the transformer and PCB too.
Now I could start checking the PSU I found that the +5v line was indeed around +2.5v. While I had the PSU powered up I suddenly got a +5v voltage output and it was pretty solid.
I couldn’t check to see if the game was running at this point as I had no way to connect the game to a monitor so I probed the video out pins with the scope and everything appeared to be at least what I expected.
While I had the PCB hooked up to load the PSU I momentarily saw the voltage on the +5v line would drop to +2.5v and then to my horror rose up to +8v!
I immediately powered it down and it has not been back on since.

I opted to hook it up to a switcher but when I did I noticed the video sync output was missing. I guess the PSU took it out. I also noticed the 8080 CPU wasn’t running either and was getting quite hot.
I’ve got access to a thermal camera right now so checking the PCB with that revealed the 8080 in the top right corner was way too hot.
flir_20160609T191950

I had no spare 8080 CPU’s so placed an order for a couple and moved onto the missing SYNC signal.

Working backwards from the SYNC output and using the schematics available I quickly found the 74LS109 at location 3B had stuck outputs despite having good inputs and a healthy clock signal.
helifire-clock
hf_109

20160611_114541

Replacing this chip gave me back my signals.

A week later my 8080 CPU’s arrived and I managed to get the video output hooked up to my Commodore 1084D monitor to test.
At the time I didn’t even realise that the game was black and white and uses a colour overlay so I was initially confused by the colour in the game but Muddymusic soon put me right on that.
IMG-20160622-WA0009

 Posted by at 7:45 pm
Jun 182016
 

Got another Konami game with the usual jail bars defect that is so common on these games

bucky3

 

I ran again the maskrom test and it reported bad maskrom 8B.

After desoldering it and testing as 27c160, the programmer complained about missing contacts on several pins.

bucky

After replacing the markrom with a 27c160, the game was 100% fixed

bucky2

 

bucky4

Jun 182016
 

I got this pcb for a repair.

Gameplay was fine but graphics had black lines and music had a lot of white noise.

ssrider

 

I ran the maskrom check and it reported two roms as bad, one of which was infact the rom with the sound data.

 

ssrider2

 

It doesn’t mean necessarily that the maskroms are bad, can be also that the custom chips have some pins not soldered correctly or the chips themselves being faulty.

The only way is to desolder the maskroms and check on a programmer if it reports pins not connected which means that the chip internally is broken.

After a check with the romset, I decided to dump rom 16k as 27c400 (4mbit eprom with maskrom pinout) and rom 1d as a 27c800 (8mbit 16bit eprom).

Both were reported as having pins non connected properly.

ssrider3

So I replaced maskrom 16k with a 27c400 and the markrom at 1d with a 27c160 eprom (16mbit 16bit eprom) after having doubled the original file in order to prevent the game to access the empty space in case the additional addrr line is not connected to GND or 5V.

This fixed 100% the game

ssrider4

ssrider5

Jun 142016
 

I had since ages this untested Phoenix PCB (manufactured by Logitec Co.,Ltd so not the Taito/Centuri version but same layout of it)

DSCN3402

Time to build the needed adapter and I powered the board up with this scenario:

DSCN3406_

All the screen was filled with a pattern of lines and dots.For first I went to dump all the ROMs on the logic board.Doing a comparison with the MAME dumps I got this result:

001.ic45: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed phoenix.46

002.ic46: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed phoenix.46

003.ic47: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed phoenix.47

004.ic48: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed 01.ic48

005.ic49: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed phoenixc.49

006.ic39: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed h6-ic50.6a

007.ic51: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed h7-ic51.7a

008.ic52: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed phoenixc.52

009.ic50: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed phoenixc.39

010.ic40: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed phoenixc.40

11.ic23: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed ic23.3d

12.ic24: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed ic24.4d

All my ROMs matched this MAME set but the two highlighted in the above list were swapped in their sockets, you can clearly notice it in the following picture :

wrong_locationPutting the two ROMs in right location restored the graphics but colors were wrong, here’s a comparison with a MAME screenshot on the right:

colors_comparison

According to MAME source, low and high bits of the palette come from two bipolar ROMs @IC40 and IC41 :

DSCN3467

I dumped them and, like the two EPROMs, they were put by someone in wrong socket:

ic40: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed mmi6301.ic41

ic41: used in Phoenix (Irecsa / G.G.I Corp, set 2) renamed mmi6301.ic40

Repositioned the BPROMs, colors came back to normal but, when I was playing the game, I noticed two further issues : shield (button two) of player 1 and 2 was not working, tracing back the involved pins from JAMMA connector I promptly found the cause:

RSCN3432

Traces were severed, perhaps from some operator to make the game harder ( and earn more money..).I patched them with a bit of AWG30 wire:

RSCN3434

The other issue concerned the audio, some effects (like shots and explosions) were missing replaced  by some whistling sounds:

With the help of schematics I could figure out that these sounds were generated by a 4006 shift register @IC45:

4006

CD4006

Clock were present on pin 3 when sounds were triggered but all its outputs were stuck high or low  (and totally missing on pin 10).

Since device was already socketed I tested it out-of-circuit in my BK560A where it failed:

4006_testing_

With a good IC all the sounds were restored but, before closing this repair, I noticed that the board was randomly missing the boot staying stuck on this garbage screen :

DSCN3436

Doing a visual inspection I noticed a missing resistor @R13 and capacitor @C2 near the 8085 main CPU :

missing__C2__R13

Checking the schematics these were involved in RESET circuitry:

missing_C2_R13

The service manual reported them as a 10uF tantalum capacitor and a 100Ohm resistor.:

R13

C2

so I promtly installed these parts :

DSCN3463

No more missing boot and fully working board!

 

 Posted by at 7:54 pm