Screen fault

[Wicksy]

P-off. While trying a new SGC my good QL lost the screen. Putting a halt to any more work on Planeframe.

Obviously no power when I put it in, but I had power to the hdmi converter and the rgb was still in. My new Cumana caused no problems when installing it in the same way, so am blaming the SGC, which was sold untested but with no battery leakage evident?

Now the black screen shows interference on a reset and no mdv1 activity on pressing f1.

I know pulling out the rgb causes something to fry, is it a soldering type fix?

I have a new 2nd QL in need of a membrane, is it important not to mix up the 3 black wires to the red, black and purple-ish one's? As am considering swapping keyboards.

[Popopo]

Hi!

I will try to give my little known...

Obviously no power when I put it in, but I had power to the hdmi converter and the rgb was still in. My new Cumana caused no problems when installing it in the same way, so am blaming the SGC, which was sold untested but with no battery leakage evident?

What is Cumana?
I suggest to do some test to your SGC with a tester (continuity mode) in order to know if it was faulty enough to cause damage to your QL (only your SGC alone, not connected).
The basis is to find shorts with power lines mainly.
Power regulators line and Caps are the most common faulty components in such cards. Other ICs also could be implied on it. But check firstly those line (+9 or +12v and GND lines).
And between VCC (+9v/+12v) and the rest of the signals lines. Same goes about GND.

I know pulling out the rgb causes something to fry, is it a soldering type fix?

The most common as far as I know, is the ZX8301. That is the video module. Also in charge of some other functions, but that is the Video module. Since it is socked, you don't need soldering skills.

I have a new 2nd QL in need of a membrane, is it important not to mix up the 3 black wires to the red, black and purple-ish one's? As am considering swapping keyboards.

Those you mean are the LEDs activities?
In such a case, black is GND and it is common to all of them, so do not worry about it. OTHERWISE, please to specify which wires you mean.

I am sorry for that bad experience with the device.

[tofro]

If you experience problems with a QL after having inserted a card into the expansion connector, don't forget to check there. It's actually quite easy to bend pins in there and create shorts with a bit of sloppy handling.

[Wicksy]

Popopo.
The Cumana is a disk interface.

Yes the LED wires, so that's good to hear.

There was a slight smell you get from electronics, but no obvious damage. Am still fuming as it was a very crisp image, the second machine from observing only the start screen doesn't seem as well defined.

Tofo.
No bent pins thankfully. Could be the power from the converter.

Am going to look at SellMyRetro for a ZX8301 to see if it's available.

[XorA]

Just to check the SGC has a 9v regulator on it, it hasnt been modified for +5V running and you just ran 9v to the whole QL?

[Wicksy]

I wasn't aware there was a need for someone to do that mod. No obvious rework.

What would need doing if that was what happened?

[Popopo]

It would be helpful if you show some images of this SGC and your QL main board.

[Derek_Stewart]

Hi,

The Super Gold Card had a voltage connector on the side to allow external powering of the SGC, via a 5V supply

The manual says:

EXTERNAL POWER INPUT

If you are using your system with a standard power supply ignore this
section. If you wish to power your system from a switch mode power
supply 5V may be fed into the Super Gold Card directly via a 2.1mm
power connector located under the heatsink. The heatsink should not be
removed and the regulator should be left in place.

Wire the plug with +5V on the outside and the centre grounded. A
suitable plug is available from Miracle Systems.

But worth looking a the under side of the board.

The Super Gold Card uses the CSYNC to synchronise the clock on the SGC board, so puilling out the Video Cable may blow the 8301.

Remove the 68008, as this is disabled, but still draws power.

Also try powering up the QL and SGC from the Mains rather than pulling the power lead from QL power input, this can kill 8301 or 8302.

[Wicksy]

Yes it has that under the heatsink, but wasn't used by me. Just used the QL powerpack.

I haven't pulled out the monitor cable, I left it in and took out the power. Then inserted the SGC. But I did leave the scart to hdmi converter powered on.


I don't trust the SGC in another machine, and am going to sell it very soon.

[stephen_usher]

Might be a useful first test for my diag ROM if you want to create an adapter and write an EPROM.

Hopefully it's not the ZX8301 though.