Lethal Enforcers repair log #1

 PCB Repair Logs, Repair Logs  Comments Off on Lethal Enforcers repair log #1
Oct 132010
 

I decided to take a look at the Lethal Enforcers board I recently bought as it had no sound.
There are many accounts of people with this problem on the forums for this board and the X-Men board, they use the same IC.
I found an excellent post over on the KLOV forums here and decided to see what I could do.
I scraped away the resin around the capacitors and with my multimeter checked continuity following the diagram user tkrn had posted in the above thread.


Capacitor C6 had leaked a little and had corroded the track between the positive side and the first pin of the 3 pin IC next to it. I removed the capacitor with a set on small pliers, it came off very easily, and replaced it plus I bridged the corroded track too.


Fired the board up and full sound is back. I haven’t replaced any of the other capacitors yet as its working but when I take this board out and store it I will probably do so just for the sake of longevity.

Many thanks to tkrn over at the KLOV forums for his excellent post, without it I wouldn’t have attempted this fix.

Bubble Bobble repair log #2

 PCB Repair Logs, Repair Logs  Comments Off on Bubble Bobble repair log #2
Oct 032010
 

Symptom: No RGB output
Cure: Traced the Red signal back to pin 6 on an LS32 (IC57) on video board, it was dead. socketed and replaced the IC and everything is back

Note: This was a (Super) Bobble Bobble bootleg board but I think the majority of the layout etc is the same

CAPCOM Commando repair log #1

 PCB Repair Logs, Repair Logs  Comments Off on CAPCOM Commando repair log #1
Sep 252010
 

Had this original Commando board for a while now but never been bothered to make an adapter up for it. Even though it may look like the JAMMA pinout, it isnt.
The original fault was garbage on screen

It turns out that in the back on the manual (found on the net) are the schematics for this board and they are nicely split into relevant sections too. After a little while of following them through I started checking the relevant inputs and outputs of the associated TTL.
I found a 74LS74 with a couple of dead pins which I removed and tested again in the Chipmaster


Fired the game up again and the backgrounds were now clear but there was still some garbage. After a little more probing I found a 74LS138 with a dead output

Replaced this and tested, the game now works fine and it also ended up being the Japanese version of the game, Senjou no Ookami.

The screen is a little off centre but this is due to my CGA – VGA adapter not being setup properly for the game.

 Posted by at 1:49 pm

Funky Jet repair log

 PCB Repair Logs, Repair Logs  Comments Off on Funky Jet repair log
Sep 072010
 

The game had way too much yellow on screen, almost impossible to see anything other than yellow.
I Traced blue/green circuit back to palette RAMs K8 and K9. Both looked fine on the scope so had to desolder the pair of them. The RAM at K8 failed a test . Socketed and replaced the faulty RAM with a 2018 and tested.

All working fine

 Older Entries  Newer Entries