4,96 - 5,32V at J4

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Glufsa
 
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4,96 - 5,32V at J4

Post by Glufsa »

Hi, i bought a x0xb0x-kit from x0x Concept a while ago, and i have just startet soldering it together, but i cant seem to get the right values at J4. on the 5v i only get between 4,96V and 5,32V. My measures on the diodes are this:

d44 0,53 - 0,00 drop:0,53
d45 1,06 - 0,53 drop:0,53
d46 4,78 - 4,25 drop:0,53
d47 5,23 - 4,78 drop:0,45

The Voltage across C3 and C5 is 32V

IC 20 is 4,88V

12V at J4 is 11,88
Any help with figuring this out?

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substyler
 
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Re: 4,96 - 5,32V at J4

Post by substyler »

hi,
the readings of D44 - D47 seems fine, IC20 too.
R4 is 5,6k? you should also check the values of R2 and R3.
what can you read at R4? (plz check both sides.. next to the trimmer TM6 and next to the 100uF cap)

the voltage across C3 and C5 is still 32V?? seems pretty much, should be something around 14V
you should also check IC22, it's maybe bad.

Glufsa
 
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Joined: Fri Jun 29, 2012 8:37 am

Re: 4,96 - 5,32V at J4

Post by Glufsa »

SubStyler wrote:hi,
the readings of D44 - D47 seems fine, IC20 too.
R4 is 5,6k? you should also check the values of R2 and R3.
what can you read at R4? (plz check both sides.. next to the trimmer TM6 and next to the 100uF cap)

the voltage across C3 and C5 is still 32V?? seems pretty much, should be something around 14V
you should also check IC22, it's maybe bad.
The voltage across both is 32V. on each capacitor it is around 15V

Glufsa
 
Posts: 5
Joined: Fri Jun 29, 2012 8:37 am

Re: 4,96 - 5,32V at J4

Post by Glufsa »

SubStyler wrote:hi,
the readings of D44 - D47 seems fine, IC20 too.
R4 is 5,6k? you should also check the values of R2 and R3.
what can you read at R4? (plz check both sides.. next to the trimmer TM6 and next to the 100uF cap)

the voltage across C3 and C5 is still 32V?? seems pretty much, should be something around 14V
you should also check IC22, it's maybe bad.
R4: 5,6k 4,27V and 2,49V

Values on IC22:

1 11,84
2 5,33
3 5,32
4 0
5 5,23
6 5,32
7 5,32
8 0

IC23:

1: 1,85
2: 5,23
3: 0

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mmm
 
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Re: 4,96 - 5,32V at J4

Post by mmm »

Check the voltages on IC23 pin 5 and pin 6. Do they differ?

Glufsa
 
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Re: 4,96 - 5,32V at J4

Post by Glufsa »

MMM wrote:Check the voltages on IC23 pin 5 and pin 6. Do they differ?
Yes:
5 5,23
6 5,32

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mmm
 
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Re: 4,96 - 5,32V at J4

Post by mmm »

This has been an issue lately (and I've experienced this as well). Interestingly enough the J4 voltage was acceptably adjustable when the IOboard was connected to the populated mainboard (read: under load).

aminoacid suggested that this is the result of a low impedance voltmeter. Still the question remains why some IOboards show this behaviour in different ways. Could be an opamp issue; I don't know.

My current suggestion is continuing with the build and then testing again with the mainboard connected.

Glufsa
 
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Joined: Fri Jun 29, 2012 8:37 am

Re: 4,96 - 5,32V at J4

Post by Glufsa »

MMM wrote:This has been an issue lately (and I've experienced this as well). Interestingly enough the J4 voltage was acceptably adjustable when the IOboard was connected to the populated mainboard (read: under load).

aminoacid suggested that this is the result of a low impedance voltmeter. Still the question remains why some IOboards show this behaviour in different ways. Could be an opamp issue; I don't know.

My current suggestion is continuing with the build and then testing again with the mainboard connected.
Thank you for the advice!

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altitude
 
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Re: 4,96 - 5,32V at J4

Post by altitude »

+1 for opamp issue. I use LM324 often for the power supply and normally swap out the trimmer for a bigger (10K) multi turn deal since I always seem to be at the very edge of the range. This happens with the 6562s as well sometimes

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