Zaccaria Repair Guides

Zaccaria was an Italian pinball manufacture that built machines from 1974 to 1987.

A list of Zaccaria machines is available using the advanced search function on IPDB.

Information on Zaccaria machines, including repair information, is available at www.zaccaria-pinball.com.

A review of replacement LED displays is available on Pinside.

1 Repair Guides

Leon's Zaccaria repair guides can be found here:

2 Zaccaria Websites/Blogs

Websites and blogs containing Zaccaria-related information and tips

Site	Description
Zaccaria Pinball	David G's site dedicated to the Italian made pinball company, Zaccaria

3 Repair Logs

3.1 Modifying the power supply to accept modern capacitors

The power supplies in Zaccaria machines contain two hard working capacitors (typically golden in color), which are collectively marked as C6 on the schematics (even though it's two parts). After forty years these capacitors are almost always exhausted and fail to filter the way the original design intended. This failure can result in a lot of noise on the +5.6VDC and +12VDC lines, spurious noise in the sound section, or in extreme cases can cause game instability. Replacement is the only option.

The original capacitors are four-post design that's difficult to source. The modern equivalent is a two-post "snap" capacitor. The original values for both pieces of C6 are 10kuF at 20V. However the power supply circuit is very forgiving so larger values for both the working voltage and capacitance amount are OK. I routinely use two 15kuF 35V capacitors as replacements and the games run just fine. Technically it adds a bit of stress to the bridge rectifier when power is first applied, so don't go crazy upsizing them. (No 1F caps!)

In order to use modern snap capacitors, a 1/16" hole must be drilled for the new location of the negative post. (We'll re-use the existing positive hole.) The easiest way to do this is to mark the position by putting the positive lug in the positive hole and scraping the green resist away with the negative lug, then drilling the hole.

Power supply, solder side, with negative holes drilled.

After the hole is drilled, scrape off the green resist around the new hole to create a new solder pad. Flux around the pad, add the new capacitor, and solder it in place.

Power supply after repair, solder side, showing used, unused, and new holes.

Power supply after repair, top, showing two new blue capacitors.

3.2 Displays show wrong numbers

Problem: On Robot, when cycling through the numbers in test, the sequence is 0-1-0-1-4-5-4-5-8-9 instead of the expected 0-1-2-3-4-5-6-7-8-9.

Cause: Dataline D1 to the displays is stuck.

Repair: After replacing U26, U30 and U34 it ended up with the 2101 RAM chip at U23 being bad. Replaced with a 5101 and displays work again.

3.3 Cabinet buttons do not work on Robot

Problem

None of the cabinet/door buttons work.

Cause

Switch matrix row 0 was not polled.

Discussion

TR3 was bad, replaced with a new BC548 and buttons work again.