JAMMArcade.net – Page 180

Superman repair log #1

Aug 112014

I got this board always from Ebay sold as faulty:

When I first powered up it I got a solid black screen.Probing the CPU I noticed some strange activity on 68000 address/data lines and watchdog was indeed active.So I piggybacked the two 62256 work RAMs @U1 and U4 and I got this:

Despite the message error,this was a good sign of life so I desoldered the two RAMs and I found them really bad:

Replaced them but still black screen and watchdog active.So, I noticed there were other two RAMs connected to 68000 CPU but not directly but through two 74LS245 and enable pin of these were stuck high.I traced back it to an output of a 74HC4075 so I started to test it with logic probe and while I was probing it suddendly the PCB succesfully booted to title screen:

I can’t really explain this but now the PCB is now working perfectly every time I power it on and this is the most important thing.See you next repair!

8086 PAL dump added

PAL Updates Comments Off

Aug 112014

Dumped and added the PAL chip from my Fluke 8086 POD.
The original is a PAL10L8 and has been converted and tested for a GAL16V8 device.

Dumping a NES cartridge

General Comments Off

Aug 112014

Recently I offered to help out someone wanting his Super Adventure Quests NES cartridge dumped.
I was quite surprised at first as I thought all NES carts had already been dumped but apparently not.

Here is the cartridge in question.

This is the same as the already dumped cartridge of Quattro Adventures. This was the NTSC release where as Super Adventure Quests was the PAL release.
The whole reason this dump in particular was wanted is because the NTSC release doesn’t work on a real PAL console using the Everdrive cartridge.

I got hold of this cart and decided the best and quickest way of dumping it was to desolder the ROM chip and read it out.

I looked online and the very small amount of information I could find suggested it was most likely a 23C2001 MASKROM pinout. As my programmer has support for this device it should have been good to go.
Well it didn’t work so after mapping out the connections on the PCB it looks like the pinout is the same as a 27C020.
This worked just fine.

Copying the iNES header from Quattro Adventures and prepending it onto my ROM allowed me to load it up in emulators to check it.

Job done. This has now been added to MESS.

X Multiply repair log #3

PCB Repair Logs, Repair Logs Comments Off

Aug 112014

Yes, again.
During some playing of this recently repaired board the game froze up.
On reset I was greeted with this static screen.

Non booting boards are generally quite easy to fault find but due to the V30 I was having problems. This is when I came across a post on KLOV from some time ago with someone asking if an 8086 Fluke POD could be used to test a V30 based system. The general thinking was that it could but no one ever tried it, until now!
Im pleased to say it does work (excluding the RUN UUT function).

Very quickly I found that the main ROM’s could not be read properly. The correct signature was 6A03 and I was getting 6935.
Following my schematics I found that there is a 74LS373 at location IC51 that is used as the latch to address the ROM’s.

This input was confirmed good but there was a stuck bit on the output.
I replaced this and the game was back once again. Ive left this soak testing and hopefully it will be rock solid now.

So just to confirm. The 8086 pod for a Fluke 9010/9100 can be used to check V30 based systems.

Metamorphic Force PAL dump added

PAL Updates Comments Off

Aug 102014

Today we have the complete set of PALs from Metamorphic Force since I dumped the second and last one.Equations has been compiled by Porchy into a GAL22V10 target device, dump is tested an working.We are cataloging all the Konami PLDs.Currently we are looking for dumps or chips from the following original PCBs:

Gryzor

Super Contra

Final Round

Gangbusters

Thunder Cross

So please let us know if you can provide them.Thanks.

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