Denial

Took several attempts ...as I only get a brief chance to snap the screen..
usually after the second boot attempt in quick succession ..
anyone seen this before on a PET ?

I think my PET has lost the will to live .. I have replaced all electrolytic capacitors except the main one ...that big green beast in the photos.. Left the PET soak testing for an hour or so .. When I checked again ..the cursor had stopped flashing ..?? so I rebooted .. but nothing on screen ? the ...

Success !!! ..
thanks again Norm..
All reassembled with new filter ...and working..
Time to start the cleaning process I think..
'HELLO OLD FRIEND - WELCOME BACK'

Not much room for manoeuvre in that tight space ..but just managed to fit the pcb ..
I'll pot it up with the hot snot gun ..and mount it back with a plastic insert under the transformer unit to add some isolation in case it moves..
will test without the PET connected later..
rgds
VS

It pays not to throw stuff away ..
Robbed this out of an old ATX PC psu ..
Re-assembled and cased should do the job nicely..
rgds
VS

I think Norm scores points here ... No obvious caps to replace under that black box next to the transformer .. but it would seem the filter caps are actually integrated into the rear of the 3 pin socket (mains in) ... removing the screews an flipping the combo socket shows the internal schematic ......

I have seen exactly what you describe happen and it was the EMI filter capacitor that is in that black box shown in the picture. It looked like the transformer blew because the smoke shot out at the transformer from the box and the smoke lingered around the transformer . When it blew it took out th...

As requested ..some pix of the PET before it failed ..and of the transformer that died..

cbmeeks wrote:Yes, you should certainly fix it or have it fixed if you can.

Could you post some pics?

I have a couple of pix I took just before it failed ..
I'll add them later ...when I get home from work.

Sorry to hear that. I had a similar experience with my PET 8032 ( http://forum.6502.org/viewtopic.php?f=4&t=4586 ). However, are you sure it's the AC transformer? Those things are usually pretty stable and last for decades (although, it's been decades since that 4032 was made...). Definately th...

...just a thought ...
but possibly multi output variable voltage switch mode psus could be used instead ..but first I would need to know what voltage and current the 3 supplies to monitor ...and mainboard actually are ?
anyone ?

:( Managed to dig my old PET 4032 out of the attic.. Let it stand at room temperature for a few hours .. Then bit the bullet and powered it up .. It started ...and was rewarded with a green screen text image .. left it running for about an hour ...then sadly it died with much acrid smokefrom the mai...

Thanks for the links Norm ..
very useful indeed ..though I do feel Im cheating a little by not doing the job myself..lol
Then again ..why try and re-invent the wheel ?

So ..I guess my problem now is how to dump the contents of a 2364 MOS rom ...?
Is there a modern USB type programmer/device with zif socket that can do this ?
If so ..please advise me ?
rgds
VS

Already had a programmed AM27C256 ..on a plug in header I made many years ago ... took a chance the contents were indeed 901486-07 ... Indeed they were ..so scraped clean a second AMBIOS 27C256 I had in the bits box ..and subjected it to the UV eraser strobe gun .. All clean FFs .. Popped it in tmy ...