We have an A55 (8705/J3U) just out of warranty (exp. June 1) that won't start. The power supply tests as good all around (Antec tester), confirming the green 115V power LED light on the back. Fans and HD come on and the HD-in-use LED lights up green in front, but the front power-on indicator LED doesn't light. No beeps for diagnosis, no video to see any POST messages, and no spin-up of CD/DVD to try booting that way. Have re-seated cables for power supply, front power switch & LED assembly, and HD.
Having checked other threads, I see that "[i]f the power button is pressed and the power light does not come on, then boot block recovery will not work." So the USB floppy and BBR idea seems out (and in any event, there hasn't been anything done to the PC recently other than the usual Windows OS and Office patches: no BIOS updates). Having verified that the power supply is good, am I now backed up to no solution other than (1) new system board, or (2) new PC? (Given that the power switch itself will start the HD & fans, and that holding it in for four seconds will turn the fans and HD back off, I'm not inclined to think that a new power switch will work. But I'm open to learn . . .. so TIA for any help.)
There should be some LEDs at the back of the machine. Which ones are lit up when your machine has not been powered up (ie., don't press the power button when looking at the LEDs)?
Thanks for asking, Netnubar. There are two LEDs on the back, above the 115/230V selector, one to the left and one to the right. If I start with the machine unattached to anything, then plug in the power cord, but do nothing else, then the right-hand LED (looking at the back) glows green. That's what I meant by the Antec power tester's results "confirming the green 115V power LED light on the back."
Following up further: The hardware maintenance manual (HMM) for the A55 (41x5730.pdf) doesn't say anything about the power supply diagnostic LEDs on the back, other than to indicate they exist. But I looked in the HMM for the _M_55 (41x6286.pdf), and found the table about them there, for the M55 models.
That table seems to indicate that my first diagnosis was correct: that my choices are (1) new system board, or (2) new PC. For my situation, where the power supply is good (as shown by the right, green diagnostic LED on the back glowing, not toention the power supply tester showing all output voltages good, etc.) but where the front power indicator stays off after the front power switch has been pressed, the _M_55 manual says "replace the system board." Too bad; I'd been hoping there might be something I'd overlooked.
Now to check the cost for the system board and heat sink retention module. Oddly, the A55 manual for type 8705 doesn't list the model (J3U) at all, only models J3B,G,H,P,S, & Y, so as to allow looking up the system board FRU. Fortunately, the FRU is on the system board itself as 43C8359.
System board is what I would try next also after reading all of the symptoms you mention. Your power supply is definately fine and it looks like the power switch is working. There is the possibility that the LEDs on the switch assembly could be out but its doubtful. A dead CPU could also cause the errors you mention but that is the least likely part to fail.
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Ed Shumpert Thinkcentre/Desktops Launch Readiness Program Manager US Service & Support
Thank you for the confirmation, Ed. I ordered a system board after posting my previous message, and having received it, have now replaced the old one (albeit with a slightly different FRU, see below) and the machine now boots fine, with one exception: it says:
"ERROR 00CE Machine Type and Serial Number are INVALID!
Update the BIOS to correct this problem."
F1 or Ctrl-S bring me to the BIOS configuration screen, but I don't see an option _there_ to just manually edit the machine type and serial number. Windows gets to the login screen, but won't let me log in, presumably because of the mismatch. A live Linux CD runs happily, though, so I'm confident the system board replacement and CPU are happily co-existing, and memtest shows no errors even after several hours, so mostly life is good.
But to run Windows, it appears I'll have to flash the BIOS. I had a potential question, because the original system board, a 43C8359, has been replaced by 45R7728, and Lenovo could only sell me the latter. It appears to have been originally for model M55e, not A55, and in particular for a model type 9637, not model type 8705-J3U like my A55 was. Fortunately, the flash BIOS update files seem to be the same for both ThinkCentre type A55 (type 8705, ...) and type M55e (type ... 9637). So I'll do that later today, and will return if there are any problems after that! I'm posting this now just for completeness, in case someone else runs into a similar issue.
Ed Shumpert wrote: "When you do the flash update you can update the MTM/SN. It will be an option on the menu that pops up right before the update starts."
Yep, exactly as you said. It happily took the serial number and machine type and model as I typed them, did a few more things on its own and then flashed (so to speak) a bright green message that all had worked. A restart later, and Windows allowed log-in. What's more, the Windows XP on the HD validates as I was afraid it might not due to the hardware change, so I don't even have the headache of having to use a restore CD or one of our volume licenses to replace the OEM OS. Yay! Thank you!
Rather than start a new thread, I'll ask this here. All's working, but I notice that the passive heat sink over the chip set in the middle is pretty hot. Any reason not to put a tiny fan on it for an assist?
