Re: iMac G5 AcBel 17" API3PC94-290 no voltages
I both pics should show what your looking for however the Pk - Pk tops out at about 370 volts on the two upper left pins when....
torgeson5kqs
Senior Member
Last Activity: 12-02-2021, 11:14 AM
Joined: 03-27-2011
Location: Nashville, TN
-
Re: iMac G5 AcBel 17" API3PC94-290 no voltages
here is a couple of pics of the setup and what I get on the scope...Leave a comment:
-
Re: iMac G5 AcBel 17" API3PC94-290 no voltages
no still the same as beforeLeave a comment:
-
Re: iMac G5 AcBel 17" API3PC94-290 no voltages
reads 1.3v - 2.5v (jumps, not steady)Leave a comment:
-
Re: iMac G5 AcBel 17" API3PC94-290 no voltages
Even after lifting one cathode at a time and measuring voltage across tied end of T2 the voltages are still zero. Is it possible T4 is shorted at the output?Leave a comment:
-
Re: iMac G5 AcBel 17" API3PC94-290 no voltages
voltage across C37 jumps from .2 - 1.6 volts
using circuit ground
B = .3-.8v, C = 1.3-2.6v, E = .7-2.4v (all these voltages jump around and are NOT stable)
0v for both D23 & D20 when measured from the cathode to the tied end of the T2 transformer as you mentioned in the above post.Leave a comment:
-
Re: iMac G5 AcBel 17" API3PC94-290 no voltages
Q1:
Voltage across C & E jumps between 1 and 2 volts
Voltage across C & B jumps between .5 and 2 volts
Voltage across B & E jumps between .2 and .4 volts
3845B:
voltage accross ground and Vcc are between 0 & .4 volts
voltage accross ground and output are between 0 & .2 volts
all others pin outs are 0 volts
TOP244YN:
input is 366 volts
output at S Pin appears to be 366 volts as well (not sure if I'm reading this right) this is also the...Leave a comment:
-
Re: iMac G5 AcBel 17" API3PC94-290 no voltages
M6 was replaced and is showing about 3.9 volts and the 5v rail bus is showing only about .6 volts. Readings taken while unjumpered.Leave a comment:
-
Re: iMac G5 AcBel 17" API3PC94-290 no voltages
I know of the Q1 and it's fine (not shorted) but where are ZD19 and M24? Topside, bottomside? what are they near?Leave a comment:
-
Re: iMac G5 AcBel 17" API3PC94-290 no voltages
Earlier in this post you mentioned hooking up a DC supply along with a scope. I have another power supply with this same problem but can't isolate the short. Could you explain how to hook both those up to run diagnostics?Leave a comment:
-
Re: Delta DPS-800GB Power Supply No Power
Wow, all that for 50 cents worth of caps. Thanks for the diagnostic toasty, I will attempt it myself and see if I have the same success. I'm concerned about those fine wires and breaking them. I don't have an air gun but a decent weller 85 watt soldering station with 85 watt pen and a large tip for better heat transfer. I let you know if this works. Thanks again for all your help.Leave a comment:
-
Delta DPS-800GB Power Supply No Power
I have a few of these redundant power supplies from some HP servers that are not responding and wanted to know if anyone has worked on them or had much luck getting them back on their feet. The Delta supplies are typically pretty well made and this is no different. I've check the fuse, MOV's, etc. and no obvious signs of damage that I can tell. Caps look good, rectifier checks out too. Let me know if you have any info on these. The connector to this power supply is a circuit board with pins on it, not your typical pin type connector. I've seen conflicting resources on the web that show which pins... -
Re: Apple iMac Power Supply Acbel API4PC47-290 Higher than normal voltage
I finally got them all working. I setup the connector so I could measure the voltage on the iMac motherboard in real time while it was in use. The voltages were all correct once their was a load on the power supply.Leave a comment:
-
Re: Apple iMac Power Supply Acbel API4PC47-290 Higher than normal voltage
Here is a layout of the voltages I get when jumpered. Let me know if this helps.
Voltages measured from ground are as follows:
3, 5, 7, 11, 14, 16, 17, 18 - Ground (-)
1, 2, 12 - 3.3v
4, 6, 20, 21 - 5.6v
8 - (Power Good) - 5.5v
9* - (Standby) - 5.0v
10, 13, 19 - 13.1v
15 - On/Off - jumper to ground (14 or 16) to run supply
22* - 23.9v (may read about 21v until switched on)...Leave a comment:
-
Re: Apple iMac Power Supply Acbel API4PC47-290 Higher than normal voltage
I've worked on several of these and never have the voltages been this high when jumpered without a load on them, which is why I thought this was odd. 5 and 24 Voltages show on the correct pin outs other than the fact that they are closer to 5.5-5.6v and 13v. This does have a the 4863G chip and TOP245YN. Let me know if you need different vantage points on the power supply....Leave a comment:
-
Apple iMac Power Supply Acbel API4PC47-290 Higher than normal voltage
I have said power supply that has had all bad caps replaced and or checked with ESR meter to ltec specs. The power supply powers on fully both on standby and when jumpered. However, when jumpered the readings on the pinout that should be 5v or 12v read 5.5 and 13volts. I have 3 power supplies all identical that have this same problem. I've checked these values with a calibrated meter as well so I know it's not my equipment. Any ideas as to what would cause an increase in these voltages? -
Re: iMAC G5 Power Supply API4PC46-290 REV.A pin 8 no voltage
Toasty,
Thanks again for all of your help.Leave a comment:
-
Re: iMAC G5 Power Supply API4PC46-290 REV.A pin 8 no voltage
Ok Anyway so is this the PFC MOSFET that is not turned on or could be bad?
Leave a comment:
-
Re: iMAC G5 Power Supply API4PC46-290 REV.A pin 8 no voltage
whats the correct voltage accross the caps supposed to be when the unit is on?Leave a comment:
-
Re: iMAC G5 Power Supply API4PC46-290 REV.A pin 8 no voltage
I get anywhere from 167 to 170 volts on the main caps depending on which power supply I check.Leave a comment:
No activity results to display
Leave a comment: