Repair Logs – Page 80 – JAMMArcade.net

Blood Warrior repair log

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Dec 192015

Another board from my friend Marco and another quick fix.Got from him this original Kaneko Blood Warrior PCB:

Blood_Warrior_PCB

On power up the board showed the “RAM CHECK OK” message but instead of going into game it was resetting in a endless loop:

missing_boot

Boardset is made of a CPU board and ROM board.Having a Great 1000 Mile Rally which runs on same hardware I could verify that the CPU board was good so the fault was located on the ROM board:

ROM_board

So, I wen to dump the program ROMs and compare them against MAME files.When I tried to read the one @U124 (a 27C010), my programmer reported a bad contact on PIN32 (VCC) and gave me an empty dump:

27C010@U124__

Device was internally damaged so I reprogrammed another one.Once fitted it, the board successfully booted into game without any further issues and I could declare also this board 100% fixed.

fixed

Cybattler repair log

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Dec 182015

My friend Marco sent me this Jaleco Cybattler PCB for a repair:

Cybattler_PCB

PCB was really in mint condition but when I powered it up I got this:

A blank screen and then the dark.First thing to do in this case is to analyze the main CPU, a 68000 on this board.The CPU was resetting properly but after few second /RESET pin was going from high to stay low, at same time also /HALT line was stuck in this logical state.This was a clearly sign of troubles with main code execution so I went to dump the two program ROMs (27C2001 devices) :

program_ROMs

When I tried to read the one marked ‘2’ @IC53 my programmer warned me about a problem on PIN32 (VCC), ignoring this obviously resulted in an empty dump :

ROM2_27C001@IC53

I programmed a new 27C2001 device and board booted properly but all the background graphics was missing or blocky:

bad_BG

Background graphics data are stored in two 4Mbit MASK ROMs (27C040 compatible) so I went to dump them and resulting files were good.But this didn’t convinced me so I analyzed them with my logic probe and I found that the one @IC67 had all data lines silent :

4Mbit_MASK_ROM@IC67

When I put my finger on the solderside of this MASK ROM I could restore the graphics :

restored_BG

I programmed the 27C040 EPROM as replacement of this bad MASK ROM using the MAME ROM set file and this fixed the board completely.End of job.

Out Zone repair log #2

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Dec 162015

I got this Toaplan Out Zone PCB for a repair:

Out_Zone_PCB

When I powered it up I was greeted by this screen:

object_RAM_error

This kind of error doesn’t necessarily imply that a RAM chip is faulty but also that it can’t be “reached” from the device which wants to read/write it.In this particular hardware the device in question is a custom ASIC sprites generator marked “FCU-2” also used in other Toaplan games:

FCU-2_ASIC

I went to inspect it and found some lifted pins:

FCU-2_lifted_pins

Blocking the PCB with a vise, I did a reflow of the involved pins FCU-2_reworking

100% fixed!

fixed

Street Fighter II – The World Warrior repair log

PCB Repair Logs 2 Responses »

Dec 152015

I got this Street Fighter II – The World Warrior PCB from my friend Joachim for a repair :

SFII_PCB

Gameplay was fine (strange thing since CPS1 hardware is higly unreliable) but sound samples were missing or played randomly :

Samples are played by an OKI MSM6295 chip located on A-BOARD which take data from a ROM on the B-BOARD, looking at it I noticed some sign of reworking with a jumper wire too:

MSM6295@14D

Continuity of traces was good so I opted for replacing the chip :

MSM6295@14D_replacing_

This restored the sound samples, end of job.

Gryzor repair log #1

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Dec 142015

First I would like to thank hezkezl and channelmanic on the KLOV forum for their help when I started diagnosing this Gryzor PCB last Year.

I finally got it repaired…

1) I got first stuck at this screen on boot:

gryzor0

Dumping the program ROMs at 17A and 18A and comparing them with the ones from MAME revealed the checksum for the one labeled 633J2 at 17A was bad so I burned the rom from MAME on a 27C512 EPROM and put it in place but no changes.

While checking the PCB with a scope, I traced a suspiciously weak signal from a couple of TTLs (which seemed ok) to a Fujitsu MB8464A RAM. Pins #7, 8 and 9 on this RAM were not pulsing (signal was stuck at 1,7 V).

These pins are address lines. They are connected to:
– Pins 7, 8, 9 on 18A and 17A (program ROMS)
– Pins 9, 10, 11 on 22A (63C09 CPU)
– Pins 114, 115, 57 on 10E (custom chip)
– Pins 114, 115, 57 on 18E (custom chip)
– Pins 1, 2, 3 on 14D (LS138 – Address decoder for I/O ports)

Replacing the LS138 at 14D didn’t change anything, not really surprising as it was related to I/O (but I didn’t really know that back in the time when I did it) so next I decided to replace the 63C09 CPU at 22A… And the game booted ! …with big graphical issues and no sound:

gryzor2

2) Graphics roms are the 4x 40 pins mask roms located at 7D, 7F, 16D and 16F. I’ve read online some people having problems with these chips and needed to replace them. The content of these roms is 256kb but I only had 512kb 27C400 EPROMs (equivalent pinout to mask roms) so I needed to double the size of each original 256kb roms to fit my 512kb EPROMs. A few tries revealed I had 3 bad roms (the ones at 7F, 16D and 16F) among the 4. All the graphics were now fine:

gryzor3

3) Good progress, but still no sound…

There are 2 chips in the sound part (located at 11A and 11B) that have their reference writings scrubbed, probably in factory to avoid bootleggers reproducing it. I’ve looked online to see if I could find pictures of other PCBs that could still have these labels visible, but all the ones I found had their writings scrubbed.

Anyway, it looked like these 2 chips were the sound generating chips. Looking in the MAME driver and on datasheets revealed it was a YM2151 coupled with a YM3012 D/A converter.

Looking at the pins of the YM2151 with a scope, I noticed there was no output signal on it (pin #21) while most of the other pins on the chip had pulsing signals. I desoldered it to put a new YM2151 in place and got a pulsing signal on the output pin… But still no sound.

I then started looking at the pins of the 63B09 sound CPU at 15A and found 2 dead signals at pins #16 and 18. These are address lines so I suspected the CPU and changed it. The sound was finally back. Everything is working fine now !

Here is a picture of my PCB with all the bad chips I replaced in red:

gryzor4b

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