Sophia Programming Box Issues - No Video, No CD Spinup

[REPAIRED] Sophia Programming Box Issues - No Video, No CD Spin-up

Here we are with another Sophia System (Programming Box) that just will not function.
All I needed it to do was be capable of outputting some video and possibly playing a music CD.
Needless to say, I haven't got quite that far yet...

Presently this is what happens;
- Power to the unit is working correctly.
- One LED on the mainboard lights up.
- One LED on the A-Bus board lights up.
- LED in front of the CD drive blinks steadily.
- There is no video output.
- CD drive does not spin up discs.

DIP switches (Set for PAL region) are set as follows;

Switch Bank 1
AREA0=ON
AREA1=ON
AREA2=OFF
AREA3=OFF
NTSC/PAL=ON
6=OFF
7=OFF
8=OFF

Switch Bank 2
WS0=OFF
WS1=OFF
SCSIBOOT=OFF
SCSI ON=OFF
SIMMCART=ON
6=OFF
7=OFF
8=ON


This Sophia did not have any RAM chips or CPUs when it was received by me originally.
Since then I have sourced some CPU cards, however the part number is different to what I was expecting 171-6692B not 171-6692D.
See this thread here if you have any ideas on what the 171-6692Bs belong to or if they will work at all in a Sophia Programming box.
I noticed in the manual for the Sophia that the units shipping with 1x8MB 72-pin SIMM in socket IC11.
I've tried about five or six different chips with no change. The CD / VCD switch is set to CD.
I did try reseating the CPU cards multiple times as well as reseating the A-Bus board. Sadly still nothing.

Does anyone have any suggestions on what I can try next?

 

We're going down the capacitor replacement road it seems. Around 50 capacitors on order from Element 14 / Farnell.
Ordered enough to replace all caps on the SH-2 boards, VCD / CD board, SH-1 board, A-Bus board, and of course the mainboard.
Most are local a few need to be sourced from overseas, so the wait begins!

The lack of video output / CD spin up is not a very good sign though. That said, I've seen bad caps do some crazy things in my time.
Other folk with Sophia issues seems to at least have their CD drive spin up... so I need to get to that point at least.
I know this CD drive is working as it was tested in a VA0 Saturn recently, same goes for the SH-1 board.
I'll report back with results (or a lack of results) in the next few weeks. Fingers crossed! :victorious:

 

x

 

What's this standalone mode you speak of? Just saw it mentioned on the other thread for Headcrab as well.
And which jumpers? I can see there is no short supply of jumpers on the mainboard and A-Bus board.
I've dug through some of the manuals, especially the one for setting up the hardware - as per the switch settings above.

In regards to EPROM, already checked and it's working well. Would have been awesome if it was just a simple flash!
Well a simple erase and flash or buy a replacement chip then erase and flash! I guess like just isn't meant to be that simple.

 

x

 

Hmmm, I came across that site a few times in my search for knowledge too. Good old Steve Snake!
Here's the manual over at Antime's site.

 

Did some checking on mine that has the same problems.

When the cd is not connected system doesnt start. (so maybe you have a drive problem,not likely though),
When the mainboard with the upper board is not connected perfectly,doesnt start.
I have tried all the pcbs except mainboard and power supplies in another box and
they seem to work.
I checked all the jumpers on two mainboards (working and not) and there doensnt
seem to be any difference.
The working one is rev.0.7 and the non working is 1.02, so on the 1.02 there
is a lot of hacking done...maybe it is hacked for some reasons and it doesnt
work as the original one.

I dont know if anything can help...

 

Much obliged! I'll definitely give it another reseat or two before I go cap crazy.
Those sockets sure do hold the boards together well though. A lot of stress on an old, old board.
I'll still go cap crazy anyway though... :congratulatory:

 

Druid's quote is just someone not knowing exactly what they're talking about and being overly confusing. They just needed to say - switch the VCD switch so it's not in VCD mode

 

x

 

Its written with a marker on the pcb at the lower left corner
of the mainboard as you are looking from behind the machine.
I will make a thread with photos of the two revisions later on...

 

Not a 4.02? Like here?
Was the 0.7 on your mainboard or A-Bus board, or both?
Me? I've got a mismatched Rev 0.7 A-Bus and a Rev 1.0 Mainboard.
Looking forward to pictures as always I am sure Druid is drooling! :wink-new:

By the way, there seem to be three switch setting on the VCD / CD section.
VCD is clearly the lowest, which one of the top two is CD? And what is the other?
It clearly makes three clicks when moving it back and forth and the traces appear to different directions.
Front and back of the VCD / CD side board.

And I found while looking back at the pictures my 315-5778 is an engineering sample! Yay!

 

Well its pretty confusing...

My working sophia setup is :
Mainbord - rev.0.7
daughterboard - rev. 0.5
little pcb (it connects to mainboard and cd board) - 838-10834
and it came with a cpu and the hitachi HS7604E9D70H as a second.
The stickers outside is SG4001 16/3/95 P.REV. 5.03.

The non working now is..
Mainbord - rev.1.0E (not really clear if its an e)
daughterboard - rev. 0.7
little pcb (it connects to mainboard and cd board) - SHE103 SH1
and it came with two cpus.
The stickers outside is SG4101 26/9/94 P.REV. 4.02.
It also came with a NMI cable for connecting a cart dev.

The switch must be on the middle next to cd writing.
The upper must be to set this off...

btw have you tried setting the box to ntsc usa mode?
mine outputs only there but maybe it is my cables fault...

 

Haha, that is pretty strange! 5.03 and a newer date on the older parts!
I've did try setting the dip switches to USA / Japan mode with no change.
I've replaced the caps on the A-Bus board and there's no change.
Reseated it a few times but nothing as of yet.
I have most of the caps for the mainboard, I especially want to replace those SMD ones in the centre of the board because they have leaked.
It might be a project for today depending on if I go into work - it's pouring with rain! :grief:

Edit: Got any photos of the Rev 0.5 A-Bus board? I've never seen such an early revision of that board!

Edit 2: I am curious as to how the Sophia reacts with no RAM SIMMs installed and no CPUs installed. I assume it would be the same as what I am seeing now with no CD spin up / no video. That's why I am very concerned for Sophia and her wellbeing! Looks like work is off today. I can't get to the station without getting soaked!

Edit 3: And a big thanks for your help in troubleshooting so far! :smile-new:

 

Capacitor replacement success.
Without the CD drive, just a black screen.
Had all my settings for Europe / PAL on the dip switches, ended up switching NTSC / PAL to NTSC (Off).
Really should try it back on PAL again. Should... now for some burnt CD tests and commercially pressed discs!



Of course a big thank you to everyone who gave me input and an extremely big thank you to the fellow who sent the SH-2 CPU cards to me! :biggrin-new:
We did it! Victory!

 

So it was a capacitor problem??
Wow didnt really expect that,thanks for all the
info mate.
Time to get some caps!

 

Sure was a relief to see any video flicker on the screen! :smile-new:
Looking forward to getting the remainder of caps in the next week or so to finish it off.
I probably should think about doing the power boards while I've still got her in pieces.

 

You should recap the power boards too,
i dismantled both my sophias and saw that the caps
on the front power board in the working one are almost dead.
I think they are to blame for any problems on the
other boards.
A bit difficult to find 270uf and 470uf on 200v though...

 

Phewf! They are a bit pricy, but Element 14 / Farnell has them!
Just need to measure them up for their physical size.
I'm a little worried for my VA0 Saturns... they have those awful SMD caps as well and a lot of them!
Fun times ahead it seems! :smile-new:

 

I just got a va0 saturn i recapped the power board
and had a model 2 would power off i replaced the top202yai and now works so more recapping for me.