DIY QubIDE Parts list

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Martin_Head
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Re: DIY QubIDE Parts list

Postby Martin_Head » Mon Oct 07, 2019 10:55 am

Someone else may know if this should work? (I'm not familiar with this board, or it's circuit diagram)

If you remove all the plug-in IC's ( it looks like the two SMD IC's have something to do with the IDE socket), and plug it in. Does the QL work normally, or do you still get the bars?

If you do this would suggest to me that there is a problem with the soldering shorting something on one of the signals on the big edge connector pins.

Looking at the photo's of the card, it looks like there may be some solder splashes between joints and adjacent tracks. Give the back of the card a good clean with resin remover, or Isopropyl alcohol, and a stiff brush (old tooth brush?). And have a good look with a magnifying glass.


Derek_Stewart
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Re: DIY QubIDE Parts list

Postby Derek_Stewart » Mon Oct 07, 2019 4:44 pm

Hi,

I had a closer look at the photographs again, I would say there are problems withe soldered joints.

I would give the under side of the PCB a good clean and get rid of all the flux, then examine each solder joint and reflow the solder joint as required.

You also look at the QL expansion port to see if any pins have bent on insertion of thr Qubide interface, this easy to do. The pins can be straightened with long nose pliers.


Regards,

Derek
axeman
ROM Dongle
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Re: DIY QubIDE Parts list

Postby axeman » Tue Oct 08, 2019 5:17 pm

Does anyone know if there has to be a hard disk connected to the QUBIDE when booting a QL ?


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tofro
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Re: DIY QubIDE Parts list

Postby tofro » Tue Oct 08, 2019 6:15 pm

axeman wrote:Does anyone know if there has to be a hard disk connected to the QUBIDE when booting a QL ?


Well, if you want the boot to happen within reasonable time, yes. QubIDE retries connecting to a disk for about a minute, if I recall right. But the boot should continue normally after that time.

Tobias


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Nasta
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Re: DIY QubIDE Parts list

Postby Nasta » Tue Oct 08, 2019 10:13 pm

Martin_Head wrote:Someone else may know if this should work? (I'm not familiar with this board, or it's circuit diagram)

If you remove all the plug-in IC's ( it looks like the two SMD IC's have something to do with the IDE socket), and plug it in. Does the QL work normally, or do you still get the bars?

If you do this would suggest to me that there is a problem with the soldering shorting something on one of the signals on the big edge connector pins.

Looking at the photo's of the card, it looks like there may be some solder splashes between joints and adjacent tracks. Give the back of the card a good clean with resin remover, or Isopropyl alcohol, and a stiff brush (old tooth brush?). And have a good look with a magnifying glass.


The card must NOT be inserted without the two IDE GALs or the HC688 address decoder because the signals driving the two SMD chips which convert the QL's 8-bit data bus to IDE 16-bit datga bus will receive random control signals and will drive both the QL data bus and the IDE data bus randomly, i.e. when they are not supposed to, resulting in a non-functioning setup.

I had a look at the pictures and i can see about two dozen problematic solder joints, mostly cold solder joints where the IDE connector is and the address selection jumper for Qubide. In particular, the latter can result in all sorts of problems as it may map the Qubide interface in the middle of the OS ROM for instance, which will crash the QL for sure.
There is also a potential short to a surrounding ground somewhere round the middle of the board where one of the RAM or ROM pins (I think) is making a solder bridge to a ground fill, the blue solder mask has been slightly damaged along the edges of the ground fill exposing bare copper.
All of this must be fixed before it has a proper chance of working - and not eventually damaging something on the motherboard!
Also, the third GAL must be present if the RAM chip is in it's socket.
And, of course, if any GALs are present, they MUST be properly programmed or they either don't generate signals at all (and they should) or, if previously programmed, will do who knows what and may even be damaged when used on the board. The function of some pins on the GAL is programmable and if incorrectly programmed, it can end up with a pin being an output when it's supposed to be an input, so it will drive a signal together with something else connected there. If one drives opposite than the other, one or noth may end up damaged.


Nasta
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Re: DIY QubIDE Parts list

Postby Nasta » Fri Oct 11, 2019 11:37 pm

top.jpg


bottom.jpg


Note red arrows. There are a couple of different problems, when you can see the outline of the PCB pad around the solder, it's likely a bad/cold solder joint/ There are also a few pins on the SIL resistor pack where the surrounding ground fill has been exposed, and it's possible some pins are shorting to ground. Same thing for some of the IDE connector pins, difficult to say from the picture if it's flux residue or a possible short.



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