JAMMArcade.net – Page 90

Avenging Spirit Repair log

Oct 312016

Received this game for a repair.

The game had messed background images

avenging2

Shorting some data pins rams I found the one responsible for the tiles arrangement.

I replaced the one marked in red below and it was infact faulty but it didn’t fix completely the problem.

I noticed that the 74ls745 above it was pressed down badly like if it was hit but something.

I decided to unsolder it and test the continuity of all the pads and infact I found three of them (marked in red) that visually were OK but they had no continuity

with the other chips.

That meant that the internal pad was broken so bad it detached internally

avenging1

Making some ugly flying wiring with something I had at hand I tested the game which was fully restored

avenging4

avenging3

Double Dragon repair log #9

PCB Repair Logs Comments Off

Oct 292016

Yes, yet another Double Dragon PCB on the bench.

The board was in good shape:

100_8956

but it didn’t pass the self-test sitting on a ‘63701 ERROR:

100_8959

The /HALT line of the HD63701 MCU was asserted, this was sign of some trouble in its busses.I swapped a good chip with no change so I went to look at schematics.All was good until I found no continuity between the address line ‘A0’ (pin 50) of the MCU with pin 3 of the 74F157 @IC8:

hd63701_bus

Tracing back the address line I could figure out where connection was interrupted, exactly under the 74F157 @IC7 so I removed it.Inspecting the involved area with a USB microscope revealed a corroded trace :

bad_trace

I patched it with some AWG30 wire:

100_8979

With this fix finally the board passed the self-test but two issues were present in game : sound was missing and backgrounds had jailbars :

The first issue was due a missing 10Kohm potentiometer in the sound section:

100_8981

The backgrounds GFX data are stored into four 27512 OTP devices on video board :

bg_romsjpg

When I went to dump the ones @IC108 ans IC109 my programmer warned me about a bad contact on pin 19 (data line ‘D7’) of both :

27512ic109

Obviously the resulting dumps didn’t match the ones from MAME ROM sets so I programmed two 27C512 EPROMs as replacement.This restored graphics completely.Yes, yet another Double Dragon PCB fixed!

Van-Van Car PAL dump added

PAL Updates Comments Off

Oct 292016

I dumped a PLD from a working Van-Van Car PCB (manufactured by Sanritsu or Karateco).Device was a unprotected PAL16L2 labeled ‘VAN-83’ @IC79, there are other three PALs on PCB but they are registered and secured.Dump is tested as working in a GAL16V8 targeting device.

Sky Wolf PAL dumps added

PAL Updates Comments Off

Oct 232016

Today I dumped the PALs (three secured PAL16L8) from a Sky Wolf PCB (bootleg of Airwolf).Devices are located on CPU board.Dumps have been successfully tested on GAL16V8 targeting devices.

Kaneko Super Nova ROM board PAL dumps added

PAL Updates Comments Off

Oct 232016

Found two ATF16V8 PLD’s in a Super Nova ROM cartridge. Both were unlocked but have not been verified as my PCB has a fault. The equations look good.
The ROM board is marked ROM-2.

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