Michael Kukat
11-16-2004, 02:25 AM
Hello,
i found several posts from users having trouble with the 550W power
supply of the mentioned C class machines. And i had a look at the HP
price lists, 756 USD for a new power supply. Okay, got those C360s for
EUR 170 quite a while ago, and now my C240s (which were even cheaper)
make lots of trouble also (the 360s still working).
Symptoms:
Plug in the power cord, fans don't start in "standby mode". After
plugging out/in (with a delay of some seconds between), you might be
lucky and the PSU starts up. As soon as the fan (the PSU has 2 if i
remember right, but just one turns in standby) turns, you don't have
any problems. Until you disconnect power or get an outage or whatever.
With the time, the problem gets even worse, no matter if you leave the
box powerless or connected to mains.
My assumption: Some capacitor or so (maybe more) have dried out, and
so some security functionality in the power supply initiates a
shutdown or maybe timeout while starting up. It also maybe some
voltage is too wavy due to lack of capacity.
I plan to find this problem, and maybe this can help many C class
owners, if i really get those beasts fixed. But before i do so, i just
want to drop in the question if anyone already did this job without
publishing the results? Any hints? Anyone schematics of the PSU? Last
time i opened it, it looked quite complex, compared to "standard"
switchmode PSUs.
Any hints welcome. And if i get nothing, i'll post results of my own
investigations as soon as they are useable.
....Michael
i found several posts from users having trouble with the 550W power
supply of the mentioned C class machines. And i had a look at the HP
price lists, 756 USD for a new power supply. Okay, got those C360s for
EUR 170 quite a while ago, and now my C240s (which were even cheaper)
make lots of trouble also (the 360s still working).
Symptoms:
Plug in the power cord, fans don't start in "standby mode". After
plugging out/in (with a delay of some seconds between), you might be
lucky and the PSU starts up. As soon as the fan (the PSU has 2 if i
remember right, but just one turns in standby) turns, you don't have
any problems. Until you disconnect power or get an outage or whatever.
With the time, the problem gets even worse, no matter if you leave the
box powerless or connected to mains.
My assumption: Some capacitor or so (maybe more) have dried out, and
so some security functionality in the power supply initiates a
shutdown or maybe timeout while starting up. It also maybe some
voltage is too wavy due to lack of capacity.
I plan to find this problem, and maybe this can help many C class
owners, if i really get those beasts fixed. But before i do so, i just
want to drop in the question if anyone already did this job without
publishing the results? Any hints? Anyone schematics of the PSU? Last
time i opened it, it looked quite complex, compared to "standard"
switchmode PSUs.
Any hints welcome. And if i get nothing, i'll post results of my own
investigations as soon as they are useable.
....Michael