Apollo 1240 = Black screen

[Dougal]

Hi guys,

I need some help maybe i can be pointed in the right direction.

My Apollo 1240 had been working perfectly. No problems.

I opened up my A1200 and fitted a DCE Scanmagic and booted up fine and then it froze.

Would not boot, just a black screen. Not even the floppy drive sound.

Tried rebooting a few times and it worked only to crash again.

I tried removing the Apollo and reinsert it, still black screen.

I also tried removing the DCE Scanmagic, removing hard drive, floppy drive, changing power supply.

I cleaned the contacts on the A1200 mobo and cleaned the contacts on the Apollo. Still black screen.

Tried removing the ram, replacing the ram.

I pressed the Ocsilator in place. Still black screen.

One every 100 times it might boot up but crash after a few seconds.

The CPU fan is working fine and the CPU gets warm (Not hot).

Without the Apollo it works fine. I tried another accelerator (M-Tec 1230) and it booted fine aswell.

Could the problem be any of the following:

Ocillator gone bad?,
Bad PSU (it worked fine before - its an A500 one) ?
Can it be fixed?

The Oscillator is easy to remove (its actually quite loose). I did try pressing it while switching on the Amiga but no go.

The CPU is NOT socketed. Niether is the rom.

I did also try removing and re-seating the Mac130 chip.

It has no battery as i removed it cause i did not want to risk leaks. There is no leaks or corrosion. The board is fine.

Need help..

[cpiac64]

remove the oscillator/xtal and reinsert, no press all, press all cause problem with ground

[Dougal]

Originally Posted by cpiac64

remove the oscillator/xtal and reinsert, no press all, press all cause problem with ground

Tried that but no luck.

Is it possible that the PSU lost power or more likely the oscillator or something else?

If it was the oscillator would the CPU remain cold? Because mine still warms up.

I did try powering the Amiga with just the accelerator, no floppy, no hard drive and no scandoubler, just the 1084S plugged in but it still would not boot.

The problem started yesterday with the hard drive booting half way and the floppy drive making 1 or 2 clicks.

Now its just a black screen, no booting, no floppy sound. The fan on the Apollo spins up normally.

[cpiac64]

remove fastram, change the xtal, remove and insert mach 120 and 130/131

[Dougal]

Originally Posted by cpiac64

remove fastram, change the xtal, remove and insert mach 120 and 130/131

The Oscillator it has at the moment is 56Mhz.

There are a lot of oscillators on AmigaKit. Which one can i buy that will work ?

As in there are 8 Pin DIL and 14 Pin DIL and none are 56Mhz.

There is 64Mhz 14 pin dil and 66Mhz 8 pin Dil. From the picture it looks like the 64Mhz 14 pin looks most similar as it is more rectangular than square.

They are cheap enough, i could buy one. But if the Oscillator was dead would that not mean that i should have a cold CPU?

I tried removing the ram but did not help. I did remove the Mach 130 and reseat it. I did not with the 120 as i was scared of damaging it. Might try later on.

[roy bates]

have you treid the jumpers?

if you was any good with a soldering iron you could make a socket for 8 pin dil socket out of a 14 dil socket,the oscilators are wire the same.

[Dougal]

Originally Posted by roy bates

have you treid the jumpers?

if you was any good with a soldering iron you could make a socket for 8 pin dil socket out of a 14 dil socket,the oscilators are wire the same.

No point in playing with the jumpers because the card was working perfectly.

[roy bates]

trust me, its worth a try a loose jumper will stop it from working try the one marked 040 and 060 its set to 040

[Dougal]

Just tried the jumper and tried removing both mach chips and reseating them. I tried with and without ram.

Tried with HD disconnected, with floppy disconnected. with both disconnected.

Tried early startup.

Tried cleaning the contacts on the apollo, tried cleaning the contacts on the edge connector. Using Kontakt PCC (printed circuites cleaner).

Tried removing and reseating the oscillator.

All i get is a black screen. No booting, no floppy sound. Just the sound of the hard drive (when connected) and the CPU fan spinning.

[roy bates]

can you try bending the legs on the xtal so its tight in the socket?just put kinks in the legs for this,it may well be that the xtal slipped out when it was on and died.

[Dougal]

Originally Posted by roy bates

can you try bending the legs on the xtal so its tight in the socket?just put kinks in the legs for this,it may well be that the xtal slipped out when it was on and died.

Just tried now.. Still no go.

Should i buy a new xtal from amigakit ? Or try and mod an ATX PSU ?

Which xtal oscillator should i buy?

[roy bates]

what xtal are you using 56mhz?,go for something close to or at that frequency.you can use the 8 pin xtals but you will have to make an adaptor.


and while your at it, try hot glueing it down afterwards if it works.just run a bead either side of the xtal.


EDIT:-just out of interest have you got the 68040.library in libs?

[Dougal]

Originally Posted by roy bates

what xtal are you using 56mhz?,go for something close to or at that frequency.you can use the 8 pin xtals but you will have to make an adaptor.

Yes 56Mhz.

Any of these i can use without any adapters ? They have sockets on their site. Is that the adapter? same page as below,.

http://amigakit.leamancomputing.com/...x.php?cPath=45

[roy bates]

ok ive had a quick look the closest they have is a 64mhz crystal,which would overclock your cpu to 32 mhz,and.........

to use a 8 pin dil xtal in a 14 pin dil socket you would have to modify a 14 dil socket by keeping the four outside pins and the inner pins,then soldering the two inner pins to the two outer ones to make a socket for the 8 dil xtal(if that makes sense)done this myself its works great.


or,you could phone amigakit and see if they have one at the speed you need.
or,you cuold see if theres any on ebay.

[cpiac64]

xtal is 14 dil packet

move jumper near xtal, divide for 2 the frequency or direct and exclude the ic near battery

[Dougal]

Is it possible that i can find another crystal exactly the same straight fit ?

Also, is it a possibility the its the PSU? I ask because i believe that if the xtal was dead the CPU would not warm up.

[roy bates]

ive used a amiga 500 psu and a 1240 in a 1200 no probs

[Mozzerfan]

Originally Posted by Dougal

Also, is it a possibility the its the PSU? I ask because i believe that if the xtal was dead the CPU would not warm up.

As already pointed out to you at amiga.org, yes the psu CAN be the problem.

It really depends on what kind of hardware you are using, and if the A500 psu still is in tip top shape after all those years.

According to Stedys psu guide (http://www.ianstedman.co.uk/Amiga/am..._supplies.html),
an a1200/040 with 1.4 GB hd and cdrom uses 4.3A@5V.
To my knowledge, the heavy a500 psu delivers 4.5A@5V.
So I would say, depending on your hardware it could be a problem.

I believe it was RKauer who said in one of his posts, that it is recommended to use a psu at no more than 75% of it max.
Edit: @Rkauer: if it wasn't said by you, then I'm sorry, but I'm pretty sure it was said by someone here at EAB.

[roy bates]

i dont think its the psu because it wont work with anything connected to the 1200 not even the apollo on its own,but you are right you shouldent really use a psu at 100% of its load i dont use them to 50% it shortens there life span.its easy to see if its the psu just take a reading with a voltmeter off the 5 volt rail if its less than 4.85 volts it wont run(thats the lower end of the parts tolerance.)

[clauddio]

Originally Posted by Dougal

Hi guys,

I need some help maybe i can be pointed in the right direction.

My Apollo 1240 had been working perfectly. No problems.

I opened up my A1200 and fitted a DCE Scanmagic and booted up fine and then it froze.

Would not boot, just a black screen. Not even the floppy drive sound.

Tried rebooting a few times and it worked only to crash again.

I tried removing the Apollo and reinsert it, still black screen.

I also tried removing the DCE Scanmagic, removing hard drive, floppy drive, changing power supply.

I cleaned the contacts on the A1200 mobo and cleaned the contacts on the Apollo. Still black screen.

Tried removing the ram, replacing the ram.

I pressed the Ocsilator in place. Still black screen.

One every 100 times it might boot up but crash after a few seconds.

The CPU fan is working fine and the CPU gets warm (Not hot).

Without the Apollo it works fine. I tried another accelerator (M-Tec 1230) and it booted fine aswell.

Could the problem be any of the following:

Ocillator gone bad?,
Bad PSU (it worked fine before - its an A500 one) ?
Can it be fixed?

The Oscillator is easy to remove (its actually quite loose). I did try pressing it while switching on the Amiga but no go.

The CPU is NOT socketed. Niether is the rom.

I did also try removing and re-seating the Mac130 chip.

It has no battery as i removed it cause i did not want to risk leaks. There is no leaks or corrosion. The board is fine.

Need help..

The problem is the connector of the apollo 1240 which the bronze' connectors are weak/bad quality and tend to oxidize with the time
I had idem problem on the apollo 1260 which have idem buggy connector
I solved using a fine sand of paper to remove the oxide inside the connectors because normal contact cleaners do not works

anyways

you can use or invent your own method to remove the oxide of the connectors
btw, the bronze tend to darken when is a bit corrupted...then turns to green
also any oxidant also will do the job...but must be soft otherwise you can damage the connector' plastic