Tempest AR II burnt resistors

tomtime

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I just picked up a dead Tempest for next to nothing. The first thing I notice is R29 and R7 are burnt to a crisp. What value are they? It is an a035435.
 

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bad==black===0
boys=brown==1
rape=red====2
our=orange==3
young=yellow=4
girls==green==5
but==blue===6
violet=violet==7
gives==grey==8
willingly=white=9

then the %
This is the only way I can remember the resistor color code.
The resistor in the pic you provided looks like a
brown black black gold
brown is 1
black is 0
and black (multiply) 0
Gold = +/- 5%
So it is a 10 ohm resistor at 5% tolerance..

Probably a 1/4 watt and you may want to up the wattage on that resistor but I don't really know.
use the calculator to see what you have/need.
http://www.hobby-hour.com/electronics/resistorcalculator.php
 
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Thanks for the responses. I cant really see the resistors color bands since im legally color blind.
 
Thanks for the responses. I cant really see the resistors color bands since im legally color blind.

The question is not... What are the values of the resistors? The question is... What causes this to happen?

R29 & R30 are notorious for burning up due to poor connection at the edge connector causing the sense circuit to ramp up the power. R7 is burnt because the power was left on when R29 cooked.

The values for these resistors can be found in the Service Manual and the Drawing Package.

R29 = 10 ohm 1/4w
R30 = 10 ohm 1/4w
R7 = 7.5k ohm 1/4w
 
Best to elevate R29 off the board so if it burns up again the heat will not cook the PCB.


Bill
 
The question is not... What are the values of the resistors? The question is... What causes this to happen?

R29 & R30 are notorious for burning up due to poor connection at the edge connector causing the sense circuit to ramp up the power. R7 is burnt because the power was left on when R29 cooked.

The values for these resistors can be found in the Service Manual and the Drawing Package.

R29 = 10 ohm 1/4w
R30 = 10 ohm 1/4w
R7 = 7.5k ohm 1/4w

+1

You really need to look at the cause of the problem, the edge connector.
 
I can see colors, I just have a hard time telling what some are. For instance, blue/green red/purple.
 
It looks to me like the original was replaced and a new one was installed. If it was mine
I would shot gun the board. There is posts on this site on how to do this.
The edge connector is usually the cause of this particular burnt up resistor location.
By shotgunning the board, it would allow you to set the main voltage to +5.
Then you don't have to worry about burning up the AR/2 board more,
or burning up the edge connector on that valuable Tempest PCB.
 
It looks to me like the original was replaced and a new one was installed. If it was mine
I would shot gun the board. There is posts on this site on how to do this.
The edge connector is usually the cause of this particular burnt up resistor location.
By shotgunning the board, it would allow you to set the main voltage to +5.
Then you don't have to worry about burning up the AR/2 board more,
or burning up the edge connector on that valuable Tempest PCB.

I concur, R29 does not need to be replaced. If it caused the burn you see on the board, it would be a cinder. It has been replaced already. Looks like R7 got some damage when R29 burnt up.

You say it's dead — what, specifically, is it doing?
 
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