Short on Q14,15,19 AND 20

Ask questions about DIY board assembly issues, fault finding and testing. (Covers all Megasquirt versions and board.)

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ALONZO
MS/Extra Newbie
Posts: 2
Joined: Fri Jul 31, 2015 3:28 am

Short on Q14,15,19 AND 20

Post by ALONZO »

Hey Guys


I'm getting a short across two pins on Q14,15,19 AND 20 Transistors....

Has anyone else had this problem?

Ive taken Q19 and 20 off the board and still shorting out some where, Q14 and 15 look absolutely fine, should I de solder them and see if the problem is still there?

Can anyone help me out?


Thanks Jay
billr
Super MS/Extra'er
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Joined: Sun May 15, 2011 11:41 am
Location: Walnut Creek, Calif. USA

Re: Short on Q14,15,19 AND 20

Post by billr »

Post some pictures of both sides of the board, let's start with some visual inspection. In the meanwhile, I'll peek at the schematics; I confess I haven't done that yet...

Also, which two pins of each device seem shorted?
Matt Cramer
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Joined: Thu Apr 16, 2009 8:08 pm

Re: Short on Q14,15,19 AND 20

Post by Matt Cramer »

All these transistors have a very low value resistor - from 1 ohm to 0.05 ohm - across them. This can easily be mistaken for a dead short on most multimeters.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
ALONZO
MS/Extra Newbie
Posts: 2
Joined: Fri Jul 31, 2015 3:28 am

Re: Short on Q14,15,19 AND 20

Post by ALONZO »

Thank You for your help guys!

Matt you're right! there is not a short its my multi meter thats making me think there was. seems to be working fine.

Jay
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