Apollo 1240 = Black screen

[Dougal]

I tried giving it a good clean with a special brush that came with my printed circuit cleaner spray.

Also tried another A500 PSU (Heavy type) which is giving slightly above 5 volts and slightly above 12 volts.

Still no go.

I am hoping it is the oscillator crystal.

Originally Posted by clauddio

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

[roy bates]

can you see if the plastic connector has a crack in it?(when its plugged in)if there is one it will be visable around the pin end on the ridge of the connector,its very rare but it does happen.

[Dougal]

Originally Posted by roy bates

can you see if the plastic connector has a crack in it?(when its plugged in)if there is one it will be visable around the pin end on the ridge of the connector,its very rare but it does happen.

Yes had a look. It looks fine.

I can't understand how it went wrong. At the moment my only hope is that it is the oscillator crystal. If that does not fix it then i may have to send it for repairs and maybe an upgrade to 060.

[voyager]

You can not upgrade to a 060 its a mach130 chip not a mach 131.
The socket for the mach 130 is not very good. I think you have a good chance of fixing the apollo by soldering the mach directly onto the board.

Take the psu advice, converting a atx psu is not that hard or expensive. Recap your A1200 board.

[Dougal]

Originally Posted by voyager

You can not upgrade to a 060 its a mach130 chip not a mach 131.
The socket for the mach 130 is not very good. I think you have a good chance of fixing the apollo by soldering the mach directly onto the board.

Take the psu advice, converting a atx psu is not that hard or expensive. Recap your A1200 board.

Yes its a mach130. I am not an expert with soldering, best i give it to somebody who can repair them or at least solder very good.

I converted a 200 watts AT PSU yesterday. The PSU works great But unfortunately the Apollo didn't. But still i have a much better PSU now

With regards to re-capping the A1200, same, i dont want to risk damaging the A1200 like i did to an A600 when i tried re-capping. The A1200 is working fine with my Viper 1230. Maybe i can find somebody locally who would recap it for me.

In the mean time replacing the crystal oscillator in the Apollo may solve the problem possibly no ?

[voyager]

It may, it may not. I have hope for your apollo because it sometimes still works as you said. But you have tot ask around for someone to help you with that.

The problem with caps is that you don’t always see the problem until it’s too late.
I don’t think its directly related to you problem but it is needed for stable operation.

People always notice the audio cap’s when the sound is getting bad, but never notice the rest of them. I make it practice to replace every cap on every Amiga that comes my way. A few weeks ago I did my A4000 and thought well let’s do my A1200 at the same time. The 1200 worked perfectly. I replaced the caps and the result was night and day especially the audio part. Gonne make a bold statement here, all smd capacitors in Amiga’s are dead or dying no matter how much they are used and need to be replaced.

It’s that you are far away otherwise I would have done it for you.

[Hewitson]

Have to disagree with that statement, my A1200 still sounds just as good as the day I got it. I do believe the 2000 could do with a recap though, it still sounds very good, but I believe it could be slightly better.

[cpiac64]

@Dougal
if you want i test and repair your 1240, pay only p&p malta to italy and p&p italy to malta

[Dougal]

Originally Posted by cpiac64

@Dougal
if you want i test and repair your 1240, pay only p&p malta to italy and p&p italy to malta

Hi.. That would be excellent. I am waiting for a crystal in the post. Will try that first and if it does not work i will tell you

Cheers

[Mr B]

Just for the point of argument, if the crystal oscillator came lose, and didn't provide the clock frequency, would the 68040 CPU still be alive and kicking?
Not as in running, of course not, but someone told me a 680X0 CPU that is fired up, without a crystal is a certain death warrant. Never did get iny information as to why, and it sounds outlandish to me, but as it's been brought up in here i thought i'd ask if they survive or not here, so i can learn something... And not feel so confused.
B!

[roy bates]

ive never seen any 68k cpu die from having no oscilator in the socket and being on.but ive seen plenty oscilators die from working loose from the board while it was on.

[Mr B]

Good. It makes a lot more sense that it just wouldn't work if there was no clock frequency, but i haven't really had the means to test, nor the will to, had i had the means... At least now i know if a CPU is broken after fitting a crystal, then it was broken to start with.

Thanks.
B!

[clauddio]

you will see that is not the crystal .. is the buggy apolo connector

[Dougal]

The Apollo is gone. I'm not expert enough to fix it. Bought a Phase5 Blizzard 1260 instead.

[Mr B]

Originally Posted by clauddio

you will see that is not the crystal .. is the buggy apolo connector

That may very well be the case. I still haven't had time to test it, and i'm feeling more and more that i might not have the time needed to try and fix this, so i might end up looking for someone to fix it for me. It's a shame, but might be the best option for the survivability anyway. And if it turns out to be a connector, well, i got the Viper1230 to barrow one from if it comes to that...

B!

Edit
BTW, the 40 MHz DIL-14 oscillator should be the closest sure to work fit, right? (Going by the assumption a underclock is a safer bet then a overclock to test if it works. 20 vs 32MHz end speed, if i've understood things right.) I can look in to getting "the right" crystal when i've upgraded the darn thing.
/Edit

[8bitbubsy]

I haven't read all the posts in this thread, but I'll just let you be aware of something that is unstable on the Apollo accs: For some reason, the internal traces leading to the boot ROM (EPROM) pins/vias tend to lose connection with the vias. That happened to two of my apollo accs, and it's a pain in the *** to fix. If the main connector is not the issue, then try to check if the ROM traces are OK by testing random points on the acc with your multimeter in "beep mode".
It takes time, but make sure you manage to "beep" every pin of the ROM.