Surface Mount Resistor blows-

[[email protected]]

Hello- let me thank anyone in advance for helping me with my problem-
My electronics knowledge, is very limted, so I apologize in advance. I
have a circuit board which has a surface mount resistor mounted
between the +12v and a small capacitor. The resistor burns out after
about 15 minutes of use. The board goes into a video game/redemption
machine that has several (7) DC motors as well as display LEd's and
other lights, etc.

When I started repairing this game- I noticed the resistor appeared
burnt. I sent the board of for repair from one of our distributors.
(BTW the resistor is not marked, so I don't know the rating-nor do I
have schematics) The board was returned, and game play was fine for
about 15 minutes. Then the game went dead again.

I'm currently metering the power supply, with no load it shows a steady
11.54 VDC, when I put a small motor on it , the power drops to around
11.41 VDC.

Is it possible the power supply is causing this resistor to burn? If
not, what should I look for?

If anyone cares to help, please do!

I would appreciate a response to my Email @ [email protected], or I will
check back here occasionally.

I will gladly send someone a few bucks if they help me fix this
problem!

Thanks-
~Ron

 

[NSM]

Is it possible the power supply is causing this resistor to burn? If
not, what should I look for?

Did you measure the resistor value when the board was returned? How many
volts did it drop?

N

 

[Wes.]

Hello- let me thank anyone in advance for helping me with my problem-
My electronics knowledge, is very limted, so I apologize in advance. I
have a circuit board which has a surface mount resistor mounted
between the +12v and a small capacitor. The resistor burns out after
about 15 minutes of use. The board goes into a video game/redemption
machine that has several (7) DC motors as well as display LEd's and
other lights, etc.

<snip>

Hi Ron,

Just out of professional curiosity, What game is this?

Wes.
www.laigames.com

 

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The game is called "El Dorado" by Eolith, it's pretty obscure, and ours
came all the way from the UK.
http://www.coinopexpress.com/products/machines/redemption_machines/Eldorado_2546.html

Regarding measuring the resistor- Duh..NO, I guess I was so excited to
get the game back up that I didn't think of that.

 

[[email protected]]

OK- *UPDATE* I found a few bare waires on an opto sensor that counts
coins as they come out of the coin hopper- My theory, and you can help
confirm or deny, is that as the tokens are coming out of the hopper,
they *may* have shorthed these bare wires on the sensor. IF this is
true, (The sensor is +5v), could it cause the resistor to burn?

 

[[email protected]]

OK- How about this, any idea what rating fuse I could put on the power
input to protect the resistor while I troubleshoot?