Hardware Pr0n II: An Amiga 3000 Story

[Tomse]

good work Andy

[AndyLandy]

Well, it turns out that whilst the battery circuit appears to be fine, the actual clock circuit is not. I powered on the A3000 this morning and it still thought it was 11pm last night! Anyone have any suggestions on what's going on there?

(I reckon some lemon juice has got into the pendulum and it's jammed! )

[Tomse]

seems that it doesn't get a signal from the oscilator/crystal.

when powered on, does the clock tick ?

if you check pin 17 (use pin 1, 8 or 10 as ground)
if it's 0V check C193 or C192, see if R193 measures around 100Kohm

check VC190 if that is shorted to gnd. it's a variable cap which could still have liquid inside thus being shorted to gnd.

[Kawazu]

Had teh same problem with my 3000D.

The thing i did where to turn of the amiga and mesured the DC voltage from the batteri step by step to the U190.

Found out that a track where cracked just before one of the resistors so i just soldierd a smal wire from the + on the batteri side to the resistor and now it woorks just fine.

I took the liberty to cut out the clock part from the schematics. Dont know if you need it but i post it anyway.

[AndyLandy]

Well, it turns out that whilst the battery circuit appears to be fine, the actual clock circuit is not. I powered on the A3000 this morning and it still thought it was 11pm last night! Anyone have any suggestions on what's going on there?

(I reckon some lemon juice has got into the pendulum and it's jammed! )

So, I attempted to investigate to what extent the clock wasn't working. Is it completely stopped, or just running slowly. Does it tick when the machine is on? What about when it's off.

The answer, it's mysteriously started working correctly! I haven't touched anything, but now it consistently shows the correct time. Bizarro, but I'm not complaining!

Well, I should get back to playing The Settlers, my empire won't build itself!

[johnim]

I should get back to playing The Settlers, my empire won't build itself!

hi i just got that from ebay as i lost my manual for the startup codes
be nice to play again

[SpeedGeek]

@AndyLandy
Here is some tasty A3000 hardware pr0n for your viewing pleasure!

That's a Big 400 MAh Ni-Cad hacked in there! (uh...actually double sided adhesive taped). There's enough power there to run the RTC until your an old geezer just like me and rkauer!

...and just when you think you've seen all my hacks and tricks I might pull another one from my magic hat when your not looking!

[matt3k]

Great looking 3k Andy. Your a real technician.

The 3000 is simply the best amiga ever made, IMHO.

One quick hack you can do is clocking the 882 up to 50 mhz. I don't remember the details, but I'm sure the literature is out there somewhere.

I overclocked one 3k over 15 years ago and still works fine...

Cheer and terrific job.

Matt

[TjLaZer]

Finally had a read of your journey, looks great! Any progress on your case?

Also, overclocking the A3640 is NOT a good idea. Especially in the A3000. It runs way to hot stock. I had one overclocked at 33MHz in my A4000D years ago and it would lock up my machine when it was hot. It would be worse in the A3000D.

[AndyLandy]

Finally had a read of your journey, looks great! Any progress on your case?

Also, overclocking the A3640 is NOT a good idea. Especially in the A3000. It runs way to hot stock. I had one overclocked at 33MHz in my A4000D years ago and it would lock up my machine when it was hot. It would be worse in the A3000D.

Not done anything with it in a very long time. Real life caught up and I've had other projects to deal with, sadly.

As for the A3640, it's actually running an MC68040 33MHz CPU, under-clocked to 25MHz. Even if it was running at 33MHz, it'd still be cooler than the XC68040/25 that the thing shipped with. And it's got an active cooler on it as well, just for good measure. There's no risk of overheating CPUs here!

[jvdbossc]

I've pulled my machine out of storage. I upgraded the scsi chip. One think that was worth the money Mine runs with stock cpu and cybervision. I just love the a3000 The only thing that seems to drop out is the rom tower. It seems my only amiga wich wan'ts to boot every time.

[SpeedGeek]

Also, overclocking the A3640 is NOT a good idea. Especially in the A3000. It runs way to hot stock. I had one overclocked at 33MHz in my A4000D years ago and it would lock up my machine when it was hot. It would be worse in the A3000D.

As long you make adequate cooling provisions (I have the large rectangular bed of nails heat sink + cooling fan) there is nothing to fear about overclocking an A3640 in an A3000D. In fact with the A3000 mobo limited to approx. 30 MHz most A3640 and 040's wont even come close to their physical limits. However, MC68040's are much better suited to the overclocking task*.

* rkauer says XC68040's can fry an egg!

[AndyLandy]

Also, overclocking the A3640 is NOT a good idea. Especially in the A3000. It runs way to hot stock. I had one overclocked at 33MHz in my A4000D years ago and it would lock up my machine when it was hot. It would be worse in the A3000D.

As long you make adequate cooling provisions (I have the large rectangular bed of nails heat sink + cooling fan) there is nothing to fear about overclocking an A3640 in an A3000D. In fact with the A3000 mobo limited to approx. 30 MHz most A3640 and 040's wont even come close to their physical limits. However, MC68040's are much better suited to the overclocking task*.

* rkauer says XC68040's can fry an egg!

Palomino-core Athlon XP 2000+ CPUs can do this too. Even with a heatsink fitted. I've got a lovely burnt out 2000+ that I pulled from a deceased computer at work. Seems the things just occasionally just self-combust!

Hmm, all this thread-bumping is reminding me I've not prodded my A3000 in far too many months! I really must do something about that!

[TjLaZer]

Nothing fun about over heating computers! Well all I know is I live in Seattle, not Miami. And if my big box Amiga is locking up due to CPU overheating. It is not getting overclocked. I guess I need to invest in A/C in my home, but then again. I live in Seattle. lol

Also, I'm not intersted in hacking my Amiga's case to get better cooling. I like to keep my machine's case stock. If I need to cut holes, add lots of fans, water cooling, freeon. Ferget it!

[AndyLandy]

Nothing fun about over heating computers! Well all I know is I live in Seattle, not Miami. And if my big box Amiga is locking up due to CPU overheating. It is not getting overclocked. I guess I need to invest in A/C in my home, but then again. I live in Seattle. lol

Also, I'm not intersted in hacking my Amiga's case to get better cooling. I like to keep my machine's case stock. If I need to cut holes, add lots of fans, water cooling, freeon. Ferget it!

Aye. I'm with you on that. I'm not cutting up my A3000 to install additional cooling! Putting in a cooler 68040 that runs faster than stock though... That's a different matter.