Resurrecting a 5200 mobo

[zuiko21]

Hi all,

I got a 5200 mobo for peanuts -- intended for a Takky mod. Like I do with any old mobo, I washed it, but still doesn't look that great...

Anyway, I've got the wiring harness, and the (mandatory?) ROM/L2 Cache SIMM so I hooked a known-good ATX PSU to the power connector (I know the proper pinout) in order to give it a try. Without load, the +5V line reads about 5.2 V, going down to 5.06 V with the mobo attached -- looks healthy to me.

But it doesn't work No bong, no death chimes, no nothing -- there's only a faint plop on the headphones upon powering up, but that's to be expected from the audio amplifier. The 603 gets slightly warm, like a 75 MHz IC should, but U15 gets very hot after half a minute or so.

Most likely it's just toast but, just in case, am I missing something? Does it need anything else in order to boot? I have no PRAM battery, not sure if that would make a difference.

On the other hand, I've seen a similar mobo, guaranteed to work, at 120 MHz -- 5320/6320, I suppose. Will it need a ROM/Cache SIMM in order to work? If so, will the one from the 5200 do?

Thanks a lot in advance!

 

[techknight]

No, it needs nothing else to boot. I had wired up an ATX power supply to a 52XX machine years and years ago when the main power supply had failed, and i had the external DB15 connector for a monitor.

it just worked. all there was to it.

 

[zuiko21]

Uh-oh, that's bad news... would mean both of my 5200 mobos are dead xx(

On the other hand, I have no PRAM battery. Maybe they need either the battery or the ADB power line? I'll try to build a makeshift PRAM battery connector with a pin header.

 

[techknight]

mine has no PRAM batt either. and they fire right up. But mine both have ROM cards. you have to have the ROM card. Too bad your in spain, or i would send you this 5200 board that I have. it works, but to me its junk. no machine to use it in. Spare.

 

[LCGuy]

FWIW, the 5260 doesn't need a ROM SIMM - they have their ROM onboard. However, all other 52xx/63xx boards do need a ROM/cache SIMM.

 

[techknight]

Right. the spare board I have is a 5200.

 

[Bunsen]

Just my opinion, but for what it's worth, I think a 5200 series board is a cruel and awful thing to do to a poor old CC Especially considering the amount of work involved in a Takky mod. Have you thought of finding a better board? (6360, 6400, 6500, 5400, 5500)

 

[zuiko21]

Well, the 5200/6200 do have several quirks, and they definitely aren't the best performers out there... but still they are a great improvement over the sluggish original CC

The Mystic upgrade should be almost as snappy as those 75 MHz crippled PPCs, and it's a much simpler plug-and-play modification. But the LC500 series is almost unheard of in Europe, it seems; and the cost to ship one of those heavy machines from USA would be prohibitive -- unless I could find a bare, working Motherboard.

Another factor in praise of the x200 is the ability to run (even slowly) PPC-only software -- quite interesing since my first Macintosh was a 7500! Also, once the Takky work is done, upgrading that with, say, a 6500 mobo would be fairly easy.

But still don't know why can't I power up any of the 5200 mobos... it's unlikely that both went south! :?:

 

[Bunsen]

once the Takky work is done, upgrading that with, say, a 6500 mobo would be fairly easy.

That's a good point.