You're a gentleman and a legend! Thanks Bob.
From:
Bob Grieb
Sent: 04/03/2014 16:12
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] KLM376A1-PS delivering undervoltage at test points
Sent: 04/03/2014 16:12
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] KLM376A1-PS delivering undervoltage at test points
Here are my numbers for comparison:
Secondary of power transformer: 41.2 VAC
Across 4700 uF cap: 22.7 VDC, 188 mV AC (RMS)
Across 2200 uF cap: 24.6 VDC, 215 mV AC (RMS)
Bob
Secondary of power transformer: 41.2 VAC
Across 4700 uF cap: 22.7 VDC, 188 mV AC (RMS)
Across 2200 uF cap: 24.6 VDC, 215 mV AC (RMS)
Bob
From: tim p <target9@hotmail.com>
To: "PolySix@yahoogroups.com" <PolySix@yahoogroups.com>
Sent: Tuesday, March 4, 2014 9:14 AM
Subject: RE: [PolySix] KLM376A1-PS delivering undervoltage at test points
To: "PolySix@yahoogroups.com" <PolySix@yahoogroups.com>
Sent: Tuesday, March 4, 2014 9:14 AM
Subject: RE: [PolySix] KLM376A1-PS delivering undervoltage at test points
Will do that this evening UK time, Bob. Thanks for the pointers.
From:
Bob Grieb
Sent: 04/03/2014 02:06
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] KLM376A1-PS delivering undervoltage at test points
Sent: 04/03/2014 02:06
To: PolySix@yahoogroups.com
Subject: Re: [PolySix] KLM376A1-PS delivering undervoltage at test points
Hi,
Please measure the secondary voltage of the transformer as it feeds into the diode bridge, (maybe from each fuse to ground? And also the DC voltage across C13 and C14, the 4700 and 2200 uF caps. Also, please measure the AC voltage across those caps, in case there is a large amount of ripple. If we have all of those numbers we can probably tell what's going on. If one of the transformer secondary fuses is blown, you will still get voltage, just not as much.
Bob
Please measure the secondary voltage of the transformer as it feeds into the diode bridge, (maybe from each fuse to ground? And also the DC voltage across C13 and C14, the 4700 and 2200 uF caps. Also, please measure the AC voltage across those caps, in case there is a large amount of ripple. If we have all of those numbers we can probably tell what's going on. If one of the transformer secondary fuses is blown, you will still get voltage, just not as much.
Bob
From: tim p <target9@hotmail.com>
To: "PolySix@yahoogroups.com" <PolySix@yahoogroups.com>
Sent: Monday, March 3, 2014 6:52 PM
Subject: [PolySix] KLM376A1-PS delivering undervoltage at test points
To: "PolySix@yahoogroups.com" <PolySix@yahoogroups.com>
Sent: Monday, March 3, 2014 6:52 PM
Subject: [PolySix] KLM376A1-PS delivering undervoltage at test points
In my ongoing P6 power supply saga, have got UK transformer hooked up ok but test points are reading
+5 = 3.6
+15 = 10.8
-15 = -10.7
Is this likely a problem with the transformer or more likely the voltage regulating components on the 376 board? Rectifiers shot?
Have tried adjusting trimpots but that does not make result in a noticeable voltage difference on the test points.
Have tested the two main Caps and they are within tolerance.
Any help or ideas appreciated.
Cheers
+5 = 3.6
+15 = 10.8
-15 = -10.7
Is this likely a problem with the transformer or more likely the voltage regulating components on the 376 board? Rectifiers shot?
Have tried adjusting trimpots but that does not make result in a noticeable voltage difference on the test points.
Have tested the two main Caps and they are within tolerance.
Any help or ideas appreciated.
Cheers