Forum Stats

  • 3,876,077 Users
  • 2,267,057 Discussions
  • 7,912,420 Comments

Discussions

Sun Ultra 40 does not power on

Maxime G.
Maxime G. Member Posts: 11

Hi,

I have a problem with my Sun Ultra 40 workstation. It used to work great, except that the USB ports on the front panel did not respond. So I opened the workstation to see if some cable had got loose. There was nothing special to be seen inside, but after closing it back it refuses to power on. The only sign of activity is the green LED blinking on the motherboard (the one with "PWR" mark next to it). Is this LED supposed to be permanently on when the motherboard receives sufficient power (either when system in ON or OFF)?

Since parts are getting rare and expensive, I would like to avoid buying some just to try: is there an easy way to test the power supply unit?

Thank you,

Maxime

Answers

  • Nik
    Nik Blocked Member Posts: 2,879 Bronze Crown
    edited Oct 10, 2017 4:55PM

    Hi.

    Read this:

    Service manual

    Troubleshooting

    Close Cover.  I can not check, but some systems switched off, when cover open ( or not fully closed).

    Regards,

    Nik.

  • Maxime G.
    Maxime G. Member Posts: 11
    edited Oct 11, 2017 2:57AM

    Hi Nik,

    Thank you for the suggestion. Unfortunately, putting back both covers (plastic inner and metal outer) did not change anything. Before posting, I have read the service manual (which is thankfully very easy to find on the Internet) but did not find anything helpful. I have unplugged all peripherals but I don't think this prevents power-on (though a working keyboard is required to continue start-up).

    I was a bit confused because somewhere I read about a two-segment LED display on the motherboard, that reportedly shows status and error codes, but I assumed this does not apply to the Ultra 40 (maybe the Ultra 40 M2???). On mine, the only LED that I could find on the mobo are a group of three, one of them blinking (~2x / second, the one with "PWR" next to it). I enclose a photo to this message.

    Yours,

    Maxime

  • Maxime G.
    Maxime G. Member Posts: 11
    edited Oct 11, 2017 3:04AM
  • Maxime G.
    Maxime G. Member Posts: 11
    edited Nov 3, 2017 7:27AM

    Hi,

    I can't see anything like "a two segment LED display that displays the current value of port 80h" (that is mentionned in the Ultra 40 / Ultra 40 M2 service manual). Is it only present on the Ultra 40 M2? I know that sometimes you need to plug in a special card to read POST codes. Is that the case here?

    Thank you,

    Maxime

  • Maxime G.
    Maxime G. Member Posts: 11
    edited Nov 3, 2017 7:37AM

    I have found a photo of an Ultra 20 motherboard there:

    http://freesoftwaremagazine.com/articles/ultra_20m2/u20m2f2.jpg

    and indeed there is a LED display on the motherboard (next to the battery). Same for the Ultra 27.

    Could this be a mistake in the service manual or am I missing something?

    Maxime

  • Maxime G.
    Maxime G. Member Posts: 11
    edited Feb 27, 2018 11:00AM

    Hi,

    It took me a while, but I took the power supply out of the chassis and opened it. It is nicely engineered! But inside mine, there was nothing special to see (no exploded condensators or similar obvious damage). I blew a large quantity of dust out of it, but after putting it back in, nothing happens. There is still this faint blinking LED on the motherboard, but this is the only sign of activity.

    Does anyone have an idea of the expected behaviour of those LEDs?

    Thank you,

    Maxime

This discussion has been closed.