(Topic ID: 289741)

Williams System 4 MPU missing 1N4148 diode, can I use 1N4004?

By johnboy1313

3 years ago



Topic Stats

  • 6 posts
  • 5 Pinsiders participating
  • Latest reply 3 years ago by slochar
  • No one calls this topic a favorite

You

Linked Games

Topic Gallery

View topic image gallery

C23F28F1-8ECA-46B9-A081-4745E98C7F4B (resized).png
20E483CB-A150-4B71-9E69-8FF9016FF7C2 (resized).jpeg
3E7849D9-78FB-4181-A3CC-78D016F2810A (resized).png

#1 3 years ago

I’m in the process of bench testing the mpu from my recently acquired Flash machine. This is an earlier system 4 machine. I just noticed that I’m missing D3 that runs to the data switches. It’s completely gone. The BOM shows it to be a 1N4148. I have some 1N4004s here. Can I replace it with one of those? Should I replace them all with the same rating? Should I order the correct one?

20E483CB-A150-4B71-9E69-8FF9016FF7C2 (resized).jpeg20E483CB-A150-4B71-9E69-8FF9016FF7C2 (resized).jpeg3E7849D9-78FB-4181-A3CC-78D016F2810A (resized).png3E7849D9-78FB-4181-A3CC-78D016F2810A (resized).pngC23F28F1-8ECA-46B9-A081-4745E98C7F4B (resized).pngC23F28F1-8ECA-46B9-A081-4745E98C7F4B (resized).png

#2 3 years ago

Search Google for their respective data sheets.

Then order the right one.

LTG : )

#3 3 years ago

I think I'd just order the right one, get a handful as well as some caps for the power and sound board.

If it's available, get it.

#4 3 years ago

The difference between both diodes is that 1n4148 is a signal diode and 1n4004 a rectifying diode.

1n4148 will be able to operate much faster but can handle low currents only. This is used when transferring data, where current is low but lots of information goes by.

1n4004 will not operate as fast, but allows for much higher current, which is used in power supplies for example.

If, the diode doesn't need to switch fast, then it will work.

As a temporary or testing solution, yes it will work. For prolonged use, you'd best get your hands on a stack of 1n4148, as they are very cheap, and used almost everywhere.

#5 3 years ago
Quoted from Roamin:

The difference between both diodes is that 1n4148 is a signal diode and 1n4004 a rectifying diode.
1n4148 will be able to operate much faster but can handle low currents only. This is used when transferring data, where current is low but lots of information goes by.
1n4004 will not operate as fast, but allows for much higher current, which is used in power supplies for example.
If, the diode doesn't need to switch fast, then it will work.
As a temporary or testing solution, yes it will work. For prolonged use, you'd best get your hands on a stack of 1n4148, as they are very cheap, and used almost everywhere.

Thanks @roamin. I got a handful from one of the Electrical Engineers at work yesterday. He said the 4004 probably would’ve worked fine.

#6 3 years ago

They are used interchangeably on Bally and Stern switch matricies on the 76-84 machines.

Promoted items from the Pinside Marketplace
From: $ 90.00
Tools
Pincoder Store
Tools
$ 150.00
Displays
Digipinball Shop
Displays
1,300
Machine - For Sale
Allentown, PA
800 (Firm)
Machine - For Sale
Lehigh Valley, PA
$ 20.00
Electronics
Yorktown Arcade Supply
Electronics
$ 27.95
Eproms
Pinballrom
Eproms
$ 11.00
Electronics
Yorktown Arcade Supply
Electronics
From: $ 11.00
Playfields
Troxel Repair
Playfields
$ 130.00
Electronics
KAHR.US Circuits
Electronics
From: $ 9.00
Boards
KAHR.US Circuits
Boards
$ 12.50
Lighting - Led
RoyGBev Pinball
Led
$ 44.99
Cabinet - Shooter Rods
Pinball Shark
Shooter rods
$ 9.95
Eproms
Pinballrom
Eproms
From: $ 5.00
Cabinet - Other
UpKick Pinball
Other

Reply

Wanna join the discussion? Please sign in to reply to this topic.

Hey there! Welcome to Pinside!

Donate to Pinside

Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!


This page was printed from https://pinside.com/pinball/forum/topic/williams-system-4-mpu-missing-1n4148-diode-can-i-use-1n4004?hl=alexmogil and we tried optimising it for printing. Some page elements may have been deliberately hidden.

Scan the QR code on the left to jump to the URL this document was printed from.