TECH: Frenzy ZPU questions

Archived from groups: rec.games.video.arcade.collecting (More info?)

Swap the CPU chip itself with a known good, and check the reset line
and clock. Thats a good start for a locked screen with garbage.

- Matt

Archived from groups: rec.games.video.arcade.collecting (More info?)

*AHEM* before I get hopped on, that is AFTER you perform the obvious
checks on the PS voltages, etc, as you plan to do already.

- Matt

Archived from groups: rec.games.video.arcade.collecting (More info?)

I'm in the same boat as you. I spend 5 hours on my Berzerk to play it 5
minutes. Did I mention they really named these games right? Anyway, the
ribbon cables are notoriously bad. It wouldn't hurt to get a new set. I've
found that the header pins tend to get corroded too. Sometimes it isn't too
obvious until you get it under a magnifier. Also, did you check all the
voltages on the boards? The power supplies are a weak point as well. It
doesn't sound like your processor is running since the LED isn't giving any
diagnostic flashes on bootup. Beyond that I'm not a lot of help. Good luck
with it and post us some tips if you make progress.

Mark Hooks

"JDM" <cannonDONTWANTSPAMball240@netscape.net> wrote in message
news:70_Be.302$xe3.144@trndny09...
> OK, since I've fixed my Qbert I just had to get another project, this time
> 2 Frenzys to make one. The ZPU is missing in the one cab, and the other
> one has the normal battery acid damage, although light compared to some of
> the boards I've seen.
>
> When I go them home, I clipped off the NiCad and washed the board down
> with the vinegar/water mix, and scrubbed it down with an old toothbrush,
> followed by a water rinse. The corrosion is fairly minimal, but after
> drying really well and plugging the board back in, I checked everything
> else (fuses, etc.), crossed my fingers and turned it on. The LED lights,
> but there is no blinking and no tones, but I hear the amp hiss in the
> speaker. The screen is filled with multi-colored bits. The only thing I
> have done so far is removed the reset button, since the corrosion ruined
> it and had it permanantly turned on. This is really the only part that was
> badly damaged by the NiCad, but I re-soldered all the connections in the
> area below just to be sure. I'm getting all the right voltages from the PS
> and no ripple. Also, the other boards look great...no corrosive gas
> damage.
>
> Has anyone out there have any experience with these boardsets, and can
> they tell me basically what direction to start, or if this symptom is a
> problem from elsewhere? Is there any repair logs out there that I can tap
> into? I've looked the past 3 evenings online, in the group archives,
> google searching for both frenzy and berzerk and have turned up very
> little. Seems like there is not much on Stern games, or I'm just not
> looking in the right place...I have a full Frenzy manual and schematics
> sheets,
>
> Please help! and thanks in advance!
>
> Jeff
>

Archived from groups: rec.games.video.arcade.collecting (More info?)

I worked on a _Berzerk_ boardset a couple of years ago and it had a bad
transistor on the power supply that kept the processor from resetting.

Archived from groups: rec.games.video.arcade.collecting (More info?)

I had a Berzerk do the same thing a few years back. It was the LS244
addy. buffer at B6.

Good luck.
Tim in Va.

JDM wrote:

> OK, since I've fixed my Qbert I just had to get another project, this
> time 2 Frenzys to make one. The ZPU is missing in the one cab, and the
> other one has the normal battery acid damage, although light compared to
> some of the boards I've seen.
>
> When I go them home, I clipped off the NiCad and washed the board down
> with the vinegar/water mix, and scrubbed it down with an old toothbrush,
> followed by a water rinse. The corrosion is fairly minimal, but after
> drying really well and plugging the board back in, I checked everything
> else (fuses, etc.), crossed my fingers and turned it on. The LED lights,
> but there is no blinking and no tones, but I hear the amp hiss in the
> speaker. The screen is filled with multi-colored bits. The only thing I
> have done so far is removed the reset button, since the corrosion ruined
> it and had it permanantly turned on. This is really the only part that
> was badly damaged by the NiCad, but I re-soldered all the connections in
> the area below just to be sure. I'm getting all the right voltages from
> the PS and no ripple. Also, the other boards look great...no corrosive
> gas damage.
>
> Has anyone out there have any experience with these boardsets, and can
> they tell me basically what direction to start, or if this symptom is a
> problem from elsewhere? Is there any repair logs out there that I can
> tap into? I've looked the past 3 evenings online, in the group archives,
> google searching for both frenzy and berzerk and have turned up very
> little. Seems like there is not much on Stern games, or I'm just not
> looking in the right place...I have a full Frenzy manual and schematics
> sheets,
>
> Please help! and thanks in advance!
>
> Jeff
>