tech: BALLY AS-2518-22 NEED RESISTOR HELP!!

[30 million (scarily said)]

R50 on this board is toast on thsi board i just got. i could not
locate it on the schematics to see what its value and wattage is. i
did however look at this resistor on another board, and the color band
is red red gold gold (2.2 ohm). still unsure of the wattage thow.
looks to be 1/4 or 1/2 watt.

i have a 2.8 ohm (red,red,gold,silver) 2 watt resistor that actually
measures 2.6 ohm. is this ok to use this at R50? ?

[GPE]

Post by 30 million (scarily said)
R50 on this board is toast on thsi board i just got. i could not
locate it on the schematics to see what its value and wattage is. i
did however look at this resistor on another board, and the color band
is red red gold gold (2.2 ohm). still unsure of the wattage thow.
looks to be 1/4 or 1/2 watt.
i have a 2.8 ohm (red,red,gold,silver) 2 watt resistor that actually
measures 2.6 ohm. is this ok to use this at R50? ?

Quarter watt, 2.2 ohm, 5% tolerance (2.1 to 2.3 ohms).
This resistor sets your +5V at a value slightly higher than 5 volts. You
want this resistor to be pretty close to the original.

-- Ed

[GPE]

Post by GPE

Post by 30 million (scarily said)
R50 on this board is toast on thsi board i just got. i could not
locate it on the schematics to see what its value and wattage is. i
did however look at this resistor on another board, and the color band
is red red gold gold (2.2 ohm). still unsure of the wattage thow.
looks to be 1/4 or 1/2 watt.
i have a 2.8 ohm (red,red,gold,silver) 2 watt resistor that actually
measures 2.6 ohm. is this ok to use this at R50? ?

Quarter watt, 2.2 ohm, 5% tolerance (2.1 to 2.3 ohms).
This resistor sets your +5V at a value slightly higher than 5 volts. You
want this resistor to be pretty close to the original.
-- Ed

Did some looking at this. The resistor in series with the LM323K's ground
pin raises the output of the LM323K by a factor of the devices quiescent
(operating) current times value of the resistor.

Based on typical quiescent current of the LM323K at 12mA:
A 2.2 ohm resistor will raise output voltage by (2.2)(0.012) or 0.026 volts
A 2.6 ohm resistor will raise output voltage by (2.6)(0.012) or 0.031 volts
Based on worst case quiescent current of the LM323K at 20mA:
A 2.2 ohm resistor will raise output voltage by (2.2)(0.020) or 0.048 volts
A 2.6 ohm resistor will raise output voltage by (2.6)(0.020) or 0.052 volts

All of these values are small enough where either resistor will work.

-- Ed

[Ron Strom]

Post by 30 million (scarily said)
R50 on this board is toast on thsi board i just got. i could not
locate it on the schematics to see what its value and wattage is. i
did however look at this resistor on another board, and the color band
is red red gold gold (2.2 ohm). still unsure of the wattage thow.
looks to be 1/4 or 1/2 watt.
i have a 2.8 ohm (red,red,gold,silver) 2 watt resistor that actually
measures 2.6 ohm. is this ok to use this at R50? ?

Probably ok on the ohms unless it's in a critical circuit. The greater
wattage is always ok as long as you have room to fit in in there.

[Shazzam]

Post by 30 million (scarily said)
R50 on this board is toast on thsi board i just got. i could not
locate it on the schematics to see what its value and wattage is. i
did however look at this resistor on another board, and the color band
is red red gold gold (2.2 ohm). still unsure of the wattage thow.
looks to be 1/4 or 1/2 watt.
i have a 2.8 ohm (red,red,gold,silver) 2 watt resistor that actually
measures 2.6 ohm. is this ok to use this at R50? ?

R50 - 2.2 Ohm, ¼ Watt - Red/Red/Gold - Use a 2.2 Ohm (IMO) - The 2.6
Ohm is almost 20% more and will lower voltage on one the 5 Volt
output. Its like you will be adding load to the 5 volt regulator
without any work accomplished... If the 5 volt section is already
weak, it will just make it more so... If it dips below 5 volts you may
not get the MPU enough voltage for stability... I would go with spec.

Steve

[30 million (scarily said)]

thx guys, will make it right:)

[30 million (scarily said)]

thx guys, will make it right:)

[Steve Kulpa]

Post by 30 million (scarily said)
thx guys, will make it right:)

might be a good idea to rebuild the entire regulator - not too hard
and only a few parts involved.

steve
---
Steve Kulpa (cargpb10)
Hermitage, TN
http://www.geocities.com/stevekulpa/pinball.htm - Pinball
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