Caius

Aug 112014
 

I got this board always from Ebay sold as faulty:

Superman_PCB

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:

work_RAM_error

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

62256_testing

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:

Superman_title

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!

 

 Posted by at 6:38 pm

Metamorphic Force PAL dump added

 PAL Updates  Comments Off on Metamorphic Force PAL dump added
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.

 Posted by at 3:41 pm

Puzznic PAL dump added

 PAL Updates  Comments Off on Puzznic PAL dump added
Aug 072014
 

Today I dumped the only PAL on a original Taito Puzznic PCB.Dump was reversed by Porchy into a GAL20V8 and  it’s tested and working.Equation can fit also into a GAL22V10 so you can request it if needed.

Just a curiosity: this PCB is no far the smallest one I ever seen, it’s really tiny!

 Posted by at 8:02 pm

Cadash PAL dumps added

 PAL Updates  Comments Off on Cadash PAL dumps added
Aug 062014
 

I’ve just dumped all the PLDs (four in total) on the Cadash PCB I succesfully repaired.All dumps are working and tested in a GAL16V8 except one which Porchy reversed into a GAL20V8 but its equations can be complied also in a GAL22V10  targeting device.Old PAL archive from unknown source was deleted from database as well.

 Posted by at 11:06 pm

Cadash repair log #1

 PCB Repair Logs, Repair Logs  Comments Off on Cadash repair log #1
Aug 062014
 

This one came from the same lot of faulty PCBs (seven in total) as the previously repaired Growl.For the uninitiated, Cadash is an action game with some RPG elements.

Board was in good shape (it has also additional hardware for multi-link game) .

Cadash_PCB

 

When powered on I got this screen:

Cadash_issue

There was a clear problem with main code execution so I dumped the four program ROMs and none of them matched the ones in MAME.I ran these dumped ROMs in MAME and I got a similar error (different memory address due not perfect emulation of 68000 core, I guess):

MAME_cadash_error

This was enough to lead me to reprogram the four program ROMs from cadash World set into 27C010 devices.And this was the winning move which fixed the board.

Cadash_fixed

 

 

 

 

 Posted by at 3:56 pm