(Topic ID: 315867)

High voltage on 5v rail on Pinbot

By bcg1976

1 year ago



Topic Stats

  • 4 posts
  • 2 Pinsiders participating
  • Latest reply 1 year ago by Tuukka
  • No one calls this topic a favorite

You

Linked Games

#1 1 year ago

Pinbot doesn't boot. Looks like 12v rail is slightly under. -12v rail at -14v and the 5v rail on TP2 on the cpu board at 9v! Can hear an ac hum on the speakers.

Bridge rectifiers shot? What would cause a high 5v rail? Dead resistor?

Thanks,
Brad

#2 1 year ago

Most likely, shorted main transistor Q5 or bad regulator chip IC1 on power supply board.

I'm afraid the 9V has done some damage on the 5V logic

#3 1 year ago
Quoted from Tuukka:

Most likely, shorted main transistor Q5 or bad regulator chip IC1 on power supply board.
I'm afraid the 9V has done some damage on the 5V logic

Yeah, was fearing that. Just have to work through it.

Any tips on testing IC1? Or is it a common.part so just replace?

#4 1 year ago

It is a common part, so replace.

To prevent further damage, test the power supply with output connector removed, measure voltages at the board.

Promoted items from the Pinside Marketplace
$ 54.99
Cabinet - Shooter Rods
Lighted Pinball Mods
Shooter rods
$ 54.99
Cabinet - Shooter Rods
Lighted Pinball Mods
Shooter rods

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/high-voltage-on-5v-rail-on-pinbot 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.