JAMMArcade.net – Page 185

Fujitsu FM-TOWNS Marty PSU repair log

Jun 172014

I got from a German customer this nice Fujitsu FM-TOWNS Marty console.

For the uninitiated FM-TOWNS Marty a Japanese console whose hardware is derived from its “big brother” FM-TOWNS computer.It has some of the coolest perfect arcade ports ever published like Splatterhouse, Bubble Bobble, The New Zealand Story, Tatsujin Oh and others.

As every Japanese device it has to be powered by 100V/110V so European people must use a step-down converter capable to reduce our 220V/240V to proper voltage .

This is what the owner of this console forgot to do by mistake..:)

So, after some seconds the “magic smoke” came out from the console.

Obviously the console did not power at all so i opened it and I immediately noticed some blown components.In particular the main 2A fuse was blown and a 100uF 200V capacitor was literally exploded on its top.The blown fuse was a good sign since it means he made his duty blocking the excessive current flowing in the circuit but the big 100uf 200V exploded capacitor meant that this overcurrent reached also other components before the main fuse blown up.So, I decided to further investigate.Usually the first component after main fuse and filter capacitor is the bridge rectifier (which, indeed, rectifies the sinusoidal current in continuous one).In my case there was a 600V 1A bridge rectifier marked ‘S1WB S60’, here the datasheet:

https://pdf.datasheetcatalog.com/datasheet/Shindengen/mXqwrsx.pdf

Infact, as I suspected, I tested it with a multimeter and it was shorted.

So, I desoldered these three bad components:

and replaced them with equivalent ones:

Reassembled the console, powered it and got this:

Mission accomplished.

Juno First repair log #2

Jun 152014

So here is the second repair log.
Pretty simple this one but I never took any pictures of the actual fault so Ive taken a snapshot of the event in MAME to show it.

The game plays as normal but when the blue ball enemies spawn into the game the froze up on screen and did nothing as circled in red in the picture below.

On my visual inspection I noticed a 1K pull up resistor array next to the bank of 4116 RAM chips what cracked in half.

Replacing this fixed the fault.

I did initially think there was another fault as the ship movement in attract mode seemed a bit strange but after checking in MAME this is a characteristic of the non Gottlieb version. In the Gottlieb version this behavior is not present.

Martial Champion PAL dump added

PAL Updates Comments Off

Jun 152014

Well, after one month of pause (real life like sucked me..) finally I’ve found a little bit of spare time to do some updates.

So, here is the PAL dump from an original Martial Champion PCB.I can’t test it since the PCB is faulty but there should not been any problem.Please, note that there is also another PAL on the PCB but it’s a 24 pin device (a PAL20L10) so out of my dumping abilities.ASAP I will send the chip to my colleague Porchy in order to dump it.

Konami 007644 custom chip

General, Technical Info Comments Off

Jun 132014

Ive got a board that needs a new 007644 custom chip.
While im waiting to find a new one I thought I would investigate how this chip actually works.

Pin 1 = SEL – changes whether the Q outputs require a rising edge clock or not.
Pin 2 = OEY – Output enable for the Y outputs else they are inputs. Active LOW
Pin 21 = OEQ – Output enable for the Q (clocked) outputs else they are inputs. Active LOW
Pin 12 = CLK – Clock input

Pins 3-10 = Y outputs – normal outputs. If OEY is LOW these pins become outputs mirroring the state of the Q input pins. SEL and CLK pins are not used in this mode.

Pins 13-20 = Q outputs – clocked outputs. If OEQ is LOW these pins become outputs. If SEL is HIGH and CLK is HIGH these outputs will mirror the state of the Y inputs. If SEL is LOW then the outputs will only change state on a rising edge CLK.

Pretty simple and should be easy to implement in a small CPLD if ever required (next project???)

Turtles in Time & Quiz Gakumon No Susume PALs added

PAL Updates Comments Off

Jun 072014

coolmod sent me a couple of PAL chips he wanted dumped.
They are both 24 pin devices but as my PAL dumper supports them it wasnt too much effort.

This means we have both PAL dumps from Turtles in Time now.
Ive never heard of the Quiz game before but its nice to have dumped too.

Credits: coolmod

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