Hello!
First want to thank folks on this forum (Toasty, etc) for the very useful info I've found here that has allowed me to repair a PowerMac G4 MDD Samsung power supply and get this ACBel one working better!
I got a PowerMac G4 MDD for free as it was dead (not booting at all). I was able to confirm it was it's ACBel power supply as another (above mentioned Samsung) power supply works ok with the system.
With this ACBel power supply installed, the system would not boot at all, no power light blink, nothing. I've gone ahead and replaced the "12 shotgun approach caps" as noted in post 11 from this thread
https://www.badcaps.net/forum/showthread.php?t=14077
That includes C16, C29, C21, C10, C13, C43, C8, C7, C41, C35, C59, and C60. 4 of these measured bad on ESR tester, others were replaced for good measure.
After replacing those, things improved. Now when I connect only power to the PS, I get +5V and about +25V standby from pin 1 and 14. There is however a fast clicking/ticking noise from the PS - not clear from where it originates, see attached sound clip.
If I jumper the PS connector pin 11 to another ground pin, so that it'll trigger itself on, it does nothing - still hear the noise and the pins 1 and 14 voltages stay the same. Likewise, connecting it to the PowerMac (in case it needs to be under load?) still produces the noise and the system does not power on.
Anyone have suggestions as to things I can try next?
I know there's a least a few more caps on the "fan control" board as noted in the attached board layout picture, the caps in blue. I saw different comments in various places about the caps on this board, whether they're simply for fan control or if they also have some affect on other areas. So not clear if they simply just need replacing as well.
Thanks!
First want to thank folks on this forum (Toasty, etc) for the very useful info I've found here that has allowed me to repair a PowerMac G4 MDD Samsung power supply and get this ACBel one working better!
I got a PowerMac G4 MDD for free as it was dead (not booting at all). I was able to confirm it was it's ACBel power supply as another (above mentioned Samsung) power supply works ok with the system.
With this ACBel power supply installed, the system would not boot at all, no power light blink, nothing. I've gone ahead and replaced the "12 shotgun approach caps" as noted in post 11 from this thread
https://www.badcaps.net/forum/showthread.php?t=14077
That includes C16, C29, C21, C10, C13, C43, C8, C7, C41, C35, C59, and C60. 4 of these measured bad on ESR tester, others were replaced for good measure.
After replacing those, things improved. Now when I connect only power to the PS, I get +5V and about +25V standby from pin 1 and 14. There is however a fast clicking/ticking noise from the PS - not clear from where it originates, see attached sound clip.
If I jumper the PS connector pin 11 to another ground pin, so that it'll trigger itself on, it does nothing - still hear the noise and the pins 1 and 14 voltages stay the same. Likewise, connecting it to the PowerMac (in case it needs to be under load?) still produces the noise and the system does not power on.
Anyone have suggestions as to things I can try next?
I know there's a least a few more caps on the "fan control" board as noted in the attached board layout picture, the caps in blue. I saw different comments in various places about the caps on this board, whether they're simply for fan control or if they also have some affect on other areas. So not clear if they simply just need replacing as well.
Thanks!
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