Ssl4000 computer fail

[Jdm5149]

Hey there. Have my console still in storage since the fall. Going insane. I purchased the Mpower from Toft and really itching to turn this board on. But in the meantime I tried to start up the computer. The supply had all lights on but only one fan was running. Unit was really dirty and I blew out dust to get it all out. Supply was running until I tried plugging in floppy drive to computer. After reseating cards I got a red light on the floppy drive card. Then after powering down a few times the +5 and -12 lights went out. Turning back on the +5 flickers then goes off and the -12 never comes on. I’ll most likely get the tangerine once I have board running but would really like to get the computer going beforehand. Any ideas Thanks

[Jdm5149]

I’m guessing I’ll start with the regulators on the daughterboard.

[walrus]

The transformers on the daughter boards were known for failing open circuit, plus I found a few boards where the solder joints came away from the pads if you pushed hard on the components.
So a desolder/resolder of all joints was needed.
The orange capacitors definitely need replacement.

[Jdm5149]

Thanks.  The +5 light is back again. Wondering if it just the leds that are the problem. Any idea on how to check and where to check the -12v in the power supply. Or even the led   I’ve swapped the regulator cards and the -12 hasn’t returned.  The +5 would go out on startup too but now has returned to steady red.  Weird

[walrus]

The attached pictures are from my training manual from 1988 but should be correct.
The Diodes D2 D3 and D6, arrowed in red, are across the outputs of their respective power supply strips.
If you can *safely* put meter probes across them, you should be able to measure the voltages for that strip.

The individual schematics for the different supplies show on the right hand side the letter of the Amphenol pin they are connected to.
If you are powering up the supply without the computer connected, then you can probe into the Amphenol direct.

[Jdm5149]

Thanks.  I was looking into that yesterday. I have the service manual and those schematics also. I ordered new fans for the computer and concentrating on that. Also ordered a g+ drive to avoid those 8” ones.  Hopefully it works or at least Alittle easier to get working.  I guess over the weekend I will trace out the voltages.  Thanks again !!

[Jdm5149]

Replaced all 6 fans in computer. One question. Should they be blowing air down into the cards or blowing air out the top from the cards. The 3 in the computer power supply also need changing but those seem really complicated to get to.  K thanks

[walrus]

I can't remember from the last time I changed the fans, but logic suggests that as hot air rises it would be sensible for the fans to suck air out of the cage.
I bow to Matts superior reasoning.

Yes, changing PSU fans is a bit tricky, I think you have to undo at least one of the crossbars and push them to one side to lift the fans out.

[Jdm5149]

Yes. Fans are blowing air into cards.  That’s what I was thinking. Just wanted to be sure. The psu might have to wait. Those screws are real hard to get to and I’m still looking around for the -12v light being out.  Measuring the outputs on the rear connector I get like 2. Something on all of the pins except for 2 that read around 6 and 7v. Maybe I’m doing something wrong. Waiting for new drive to show up to see if it boots up at least.  Also ordered a Sony monitor to hook up.  Also I have a remote keyboard but it didn’t come with cable.  Seems it needs a scsi to ribbon cable kinda like the 3.5 drives.  Anyone know which cable is needed   Thanks again for all the reply’s

[Dave Dicson]

For the remote keyboard to work, U need SSL's interface box that plugs into the 50 way keyboard cable that goes between the console and the computer. A DB 9 serial connector cable to Lema connector is needed to plug the remote keyboard into the interface box.

[Jdm5149]

The remote keyboard I have seems different than one o
In manual.  It has a scsi output it seems like.  The pic I took is too large to upload.  I will try again.

[Jdm5149]

pics

[Jdm5149]

pic

[Dave Dicson]

Your pic looks like a custom job, that someone has taken an "E" series keyboard out of a "E" Series 4K SSL console and mounted it in it's own box? The connector looks like a 50 Pin Centronix (printer connector) also known as a Blue Ribbon Connector. I guess it has keyboard data and power in that connector. The "normal" SSL external keyboard kind of looks like a old IBM mechanical keyboard.

[Jdm5149]

So hopefully just connect to the back of computer and it should be ok ? 🤞 gonna try and hunt down where the -12v is bad.  I think I plugged the 20mb drive into the wrong card at the same time the lights on the -12 and +5 went out. Maybe I shorted something out.