I have a 17" acbel imac G5 power supply API3PC94-290 that I've fully recapped, even the tiny capacitors, with panasonic FM and FC caps. Everything powers up except that pin 22 on the power connector reads about 14 volts. This should be about 20 volts when un-jumpered and about 24 volts when jumpered. Mine reads 14 volts either way. Any help would be appreciated to figure out what is causing this voltage drop.
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Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
M6 is bad.
Trace the line back from output to standby transformer.veritas odium parit -
Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
M6 is attached by screw to heatsink, has 3 pins and is next to 1000uf 35v cap. Looks like a fairchild ka78m.. (can't read the rest) this looks to be a line regulator according to mouser.com There are a couple different versions, which do you suggest?Comment
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Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
Get the part number, then you'll know.
Now, why is it bad? What voltages do you see?veritas odium paritComment
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Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
it's a KA7M24 (fairchild) the outer pins read 14.2v and 30v inner pin reads zero. When I take the voltage across the two outer pins it reads 18.3v. Also when I type in part number to mouser (same with digikey) it shows end of life and out of stock. Is there an equivilent?Comment
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Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
sorry it's a KA78M24Comment
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Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
So, again, why is it bad...?
You can answer that by reading its' description...
Look at (get) datasheet for pinout and voltages. Do this anytime you come across a new component you don't comprehend. Usually there's at least one application schematic in the datasheet also.veritas odium paritComment
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Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
Data sheet shows input,grnd,output. In this case the output needs to be at 24v which its not and the input appears to be about 30 volts. It can handle upto 40volts input. So I've found a couple that might work. The only really difference that I can see is the line regulation is 480mv vs. 100mv on the obsolete version and the output current is 1A vs. .7A on the old one. So it appears that part KA7824TU should work (TU shows that it comes in a tube, but case package is still the same TO-220Comment
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Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
Yes!
KA7824TU will (and does!) work fine.
veritas odium paritComment
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Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
Most excellant.....
Comment
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Re: iMac G5 AcBel 17" API3PC94-290 Low Voltage on pin 22
Well what do you know it works know...... Thanks for the help on this Toasty, I really appreciate it.Comment
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Vizio e601i-A3 - Has Sound and Display, But No Backlight - Bad Power Supply Board or Bad LED Bulbs ?I was given this TV from my great uncle. He said it just wouldn't turn on one day out of nowhere, replaced the TV, and gave it to me to possibly fix and use for myself.
Upon bringing it home and plugging it up, it showed a standby light.
I powered it on and without a flashlight, the display showed the "V" but the lighting is very dim, but visible.
The screen seems to blackout and stay black, but with a flashlight I can see the display.
With my Playstation 4 connected via HDMI, and running a game I can hear sound.
Assuming... -
Hi all,
this unit comes from a samsumg LCD TV LE32C530F1W which stopped working after making a strong noise like something was exploded inside of it.
I opened it and found that fuse FP801S was blown, capacitor CP814 was completely disintegrated and MOSFET QP801S was shorted.
I replaced all of them and instead of the fuse I connected a 100 Watt bulb. Then, without connecting it to other TV boards, I switched it on, but the bulb begun to blink.
I thought that maybe the bulb was somehow interfering with the normal operation of the power supply, so I replaced it with a fuse,... -
Hi all,
this unit comes from a samsumg LCD TV LE32C530F1W which stopped working after making a strong noise like something was exploded inside of it.
I opened it and found that fuse FP801S was blown, capacitor CP814 was completely disintegrated and MOSFET QP801S was shorted.
I replaced all of them and instead of the fuse I connected a 100 Watt bulb. Then, without connecting it to other TV boards, I switched it on, but the bulb begun to blink.
I thought that maybe the bulb was somehow interfering with the normal operation of the power supply, so I replaced it with a fuse,... -
Hello friends,
Looking for some guidance here. The RAM voltage circuit on this motherboard keeps burning out PU301 which is a RT8231AGQW. Copy of the board with the burnt chip attached with some voltage measurements and copy of the schematics also included.
I think I've checked almost every component in the circuit, but when I change the RT8231, the laptop starts I have 1.2V on the inductor for about 10 seconds and then the RT8231 goes south and no more voltage on the inductor. All other voltages on the laptop are good, this is the only one conking out for a reason I... -
i have Gigabyte Z490 Gaming X Motherboard .it has a power on no display fault .. no vcore voltage and debug led stuck CPU LED .
VCCIO voltage ok
VCCSA Voltage OK
VCCPLL Voltage OK
Ram Voltage ok
RamVTT OK
VPP 2.5 OK
But No Core Voltage
and i want to this vrm ic datasheet or pinout (ISL69269)
anyone have this ic pinout voltages?...06-25-2025, 07:19 AM
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