Repair Logs – Page 84 – JAMMArcade.net

Haunted Castle repair log #1

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Nov 042015

Got this Konami Haunted Castle PCB for a repair:

When I powered it up for first time, two were the faults I noticed : sound and sprites were missing.So I started to troubleshoot first issue.The sound circuitry of this hardware is made of an Z80 CPU,a 6116 SRAM, a 27256 ROM and YM3812 DAC plus a couple of custom for PCM samples and music generation (K007232 and ‘K051649’).When I went to probe the Z80, I found that most of data lines were stuck LOW or HIGH.The ROM containing sound code was good as well as the relative RAM.With the help of schematics I figured out that sound code data were latched by a 74LS374 @G11 :

Probing its outpus revealed they were stuck and piggybacking it caused playing some random samples.So I decided to remove the IC :

It failed when tested in my programmer:

Sound was fine but, as I said, sprites were missing (except for some):

Since I already repaired in the past a couple of Haunted Castle boards with identical issue, I knew where to look at.Hardware uses for sprites and tiles some 4464 DRAMs in ZIP package.In particular the two related to sprites are the ones @H3 and @H4:

So I ordered some spare parts from China.When they finally arrived , I could successfully finish my job by replacing them:

Another great game preserved!

Capcom CPS-B-01 C-BOARD repair log

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Nov 032015

Just a quick (but quite important) fix.Got from my friend Josef this spare Capcom C-BOARD with CPS-B-01 ASIC on it:

Whatever game I tried with it, I got sprites issues.Strider for example:

I was pretty sure the CPS-B-01 ASIC was bad, it’s very prone to failure IC but I decided to have a look at it.Doing a continuity test with my multimeter on solderside of the C-BOARD I found two broken traces:

I promptly patched them with some AWG30 wire:

This restored correct sprites:

SEGA Mega Play repair log

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Nov 022015

My friend Joachim sent me this Mega Play system for a repair:

The Mega Play is the name of a JAMMA-based arcade boardwith the ability to run Sega Mega Drive games. It was the second attempt by Sega to bring the home console to the arcades, following the Mega-Tech arcade system.Games come in form of cartridges:

At power up the system booted but got stuck on the welcoming screen not loading cart in whatever slot was inserted:

As I said, this system operates on the same core components that the Sega Genesis uses (plus some additional hardware, such as an additional Z80 and Master System VDP for driving an optional second monitor that displays a list of games installed).In particular there are two VDP (Video Display Processor) custom chips marked ‘315-5433’ and ‘315-5313’.When I went to inspect them, I found some lifted pins on the latter :

In particular lifted pins were some from 55 to 70 which are directly connected to the 68000 main CPU data bus :

I reflowed these pin and this was enough to fix the board:

Out Run repair log #2

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Oct 282015

My friend Alexander sent me this original Sega Out Run PCB for a repair:

After adapting it to JAMMA I powered it up and I could noticed the defect :

There were some dots on the screen in which I could recognize parts of sprites (lile a ghost images, I’d say).Since video board is the lower one, I could not reach with my logic probe or scope the involved circuitry made of the 315-5211 custom Sprite Generator plus sixteen 62256 SRAMs chips :

RAM test was successfully performed but didn’t cover all the chips :

So I went to piggyback each RAM chip and when i did it for the one @IC71, the issue was cleared:

Time to remove the chip and install socket:

Obviously the desoldered chip didn’t pass the test on my programmer:

End of job.

Tube Panic repair log #2

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Oct 282015

Another double Tube Panic PCB repair, with this so far fourth are the PCBs I repaired for my friend ‘robotype’ (you can find here the first log).Let’s start with first one :

As label said, sprites were totally missing:

Sprites generation circuitry is located on the video board.ROMs were all good so, due lacks of schematics, I went to test components with my HP10529A logic comparator.When I clipped a 74LS161 counter @E8, comparator reported troubles on all its output pins:

It failed the out-of-circuit test:

With a good IC fitted, sprites came back :

First board 100% fixed, let’s pass to the second one which was labeled with “BAD SPRITES” (it seems sprite issue is a common failure on all the Tube Panic PCBs) :