5200CD won't start/do much of anything

Question

We have 5200CD that won't start up. My father (whose beloved computer it is now) had noticed that he was having difficulty getting it to start - sometimes, he would have to press the start up key two or three times - so he left it running for a couple weeks before it went off on its own overnight.
We could not get it to start up again - pressing the startup button gets a clicking (my father's description) or popping (my description) sound. If the button is held down, it'll keep making the sound, regularly spaced. Nothing else happens - screen stays black and none of the usual pre-startup machinery whirring and purring can be heard.
We swapped out the keyboard for one of a similar age (couple years newer) - no effect.
We replaced the battery - no effect (though now you can get it to pop once without the power cable plugged in).
I see mentions of power supplies causing similar issues, but I can't seem to find one or even the mention of one in connection with a 5200 online, so I don't actually know if the 5200 has one or where I would find it to examine it if it does (or how to examine it).
Dad does have most of his files on an external hard drive, but his backups did not include the files on his desktop, and he would like them. Ideally, he would prefer to have "his" computer running (he misses OS 7.5.5).
Incidentally, the 5200 has a comparatively new hard drive, having previously had its original hard drive die, so I don't think it's the hard drive.
Any suggestions?

Answer 1

Glad to hear you recovered your data.
From the sound of things I would guess the analog board is shot. Glad to hear that you recovered all your data though.
Of note, that PC hard drive may not work unless it was formatted for the Mac OS.
But I suppose before giving up on her, have you tried starting up from the *rear power* button?
If yes, did you try pulling out the logic board to carefully check the connector strip for corrosion which could cause a bad contact? If you have contact cleaner try carefully wiping it, note that you can dislodge the gold 'pins' very easily!
Also try the silly simple things such as power cable and a different wall outlet.
But if it is pooched it is probably not cost effective to repair (it pains me greatly to say this as I am a serious collector of old Mac hardware...) since an analog board replacement is both dangerous from a voltage standpoint and labour intensive because you wind up stripping the whole thing down. A quick and dirty fix would be to replace the outer shell, tube and analog board and just slide in your old components such as MB. I'd only do this if you can find the parts for $20 or less.
A better expense would be to source out a used eMac or even iMac G3 though my money is on an eMac which is a G4 cpu and can be found second hand for $75 more or less. Be careful with the 1.25GHz model as it has issues with capacitors going although these tend to be the ones going really cheap. I own one of these and it is great, runs Tiger fine when topped up with memory and big hard drive. Also installed a D/L DVD burner.
A used iMac 600MHz DV should set you back no more than $50.....
Kevin