May 012014
 

Another new day, another PCB repair. An easy and lucky one with a strange epilogue though.Got this original Bionic Commando PCB from Ebay as non working:

IMAG0236

When I received the board I noticed a piece of tape on it saying “WON’T BOOT” so I was ready to a static garbage screen or worse, a nice black one.So I powered up the board and I got this instead:

IMAG0239

Video had jailbairs all over the screen, gameplay and sounds were OK.So, as usual, before starting my troubleshooting, I made a visual inspection that revealed :

One 74LS367 was missing, another one was cracked and, the icing on the cake, solderside of the video board had a lot of scratches but at the end I found only one broken track that I jumpered with a bit of solder.

So, fitted a new 74LS367 and replaced the cracked one, I was confident about but I was wrong, there was no change at all, jailbars were always present.

So, with the help of the schematics, I started to check everything related to the issue .I dumped the ROMs containing the tiles and they were fine against MAME,  did some in-circuit testing with my B&K 560A IC tester but nothing was wrong in the presumed involved parts of circuit.After some hours of investigations I was giving up when I decided to check the voltages on PCB.I measured +5.1V on a IC so I lowered it a bit but without immediate success.A little frustrated I powered off the board and then after some minutes on again and I got:

IMAG0238

 

I don’t know if this is really related to the voltages (I raised to +5.1 again and jailbars didn’t appear), the fact is I finished the game and no issue occurred again.Oh, I love the soundtrack of 1st level, it reminds me the happy days playing this game on my Commodore 64.Another day spent, another great classic added to my collection…

 Posted by at 9:25 pm