CC (re-capped) Stopped Booting

[LazarusNine]

Hello all,

 

The short version: The CC (re-capped) no longer boots. I seek guidance.

 

The long version: I booted my Colour Classic earlier today after about 8 months of non-use and I ran into a series of issues. Let me start by saying that the CC has an LC 550 logic board. Both the logic board and the analogue board (integrated power supply) were fully recapped around two years ago (ceramics, tants, and electrolytics where necessary) with ONE exception. I had the wrong sized 330uf 400v, so had to resit the original (see photo). Nevertheless, the CC operated perfectly well after all that.

 

Today is a different story. When I first booted the computer, I noticed that the screen was continually dimming and brightening, almost alongside the speed at which the hard drive was spinning. I initially thought there was an issue with the screen (flyback?). However, after rebooting twice and then trying a third time, the CC stopped booting altogether. When I flick the power switch, I hear the screen get a bit of juice, but soft power boot with the keyboard (tried multiple keyboards and different ADB ports) results in absolute silence - there's no indication whatsoever that a boot was attempted. So, now I'm wondering if it's a power issue. If so, what steps should I take to start discovering the culprit? Could it be that ONE remaining capacitor that needs changing (something I intend to do now anyway)? Might the fuse be blown as well? What's the rating on that?

 

Thanks in advance.

Edited March 24, 2018 by LazarusNine

[IlikeTech]

Pull the lobo and hit the power switch.  Does the fan and hard drive come to life?

[LazarusNine]

28 minutes ago, IlikeTech said:

Pull the lobo and hit the power switch.  Does the fan and hard drive come to life?

Yes! So, might it be a logic board issue then?

Edited March 24, 2018 by LazarusNine

[IlikeTech]

Yep, got the original CC lobo?  Use that to test.

[LazarusNine]

Unfortunately, I no longer have it as I sold it on after getting the 550 board. The original lobo needed fixing at the time.

[LazarusNine]

Well, I feel silly. After removing the battery holder and resitting it (and a couple capacitors) to make sure no old capacitor goo was lying around, I noticed a bit of grime on the logic board connectors. Gave them a good clean and now the machine is up and running again.  Thanks for your patience with me.

Edited March 24, 2018 by LazarusNine