Preventative Medecine

[Simon_Carr]

I'm rapidly getting hooked on my QL... I'm astounded with how good it is. For a nearly 30 year old computer it was way ahead of the competition (as a Mac user, I even think it was better than the first mac in terms of capability) and one cannot help but think 'if only they had got it right for launch day'....

Still dabbling with SuperBASIC, which seems to be so easy to learn, even compared to BASIC on the ZX Spectrum, but I'm having fun all the same.

Anyway, my post is a question that jumps way ahead of myself as usual... Having got this fantastic computer, what should I do to keep this in tip top condition for years to come? I have messed around with quite a few Spectrums, changing old electrolytic capacitors, transistors, ICs and voltage regulators, but is there a set of equivalent recommendations for things that could/should be done to a QL? I assume that a change of electrolytic capacitors is wise, but I haven't even dared open the thing up yet to see what it looks like inside!

I'm in no great hurry to open up the QL (I'm enjoying using it too much at the moment), but any suggestions for little bits of TLC would be much appreciated. I assume that there are no special things to be done to open the computer up: From looking at membranes on eBay I have guessed that there will just be the molex connectors for the keyboard, and possibly some sockets for the two microdrives to release before the motherboard can be properly looked at?

[vanpeebles]

If it's working fine I'd keep using it until otherwise Just watch out for a chirping PSU. Also once you open them it tends to finish off an old keyboard membrane

[Dave]

You'll find that replacing the electrolytic closest to the 7805 on the +5v line is useful. Buy a replacement membrane before you even open the QL - it will not work once stressed by opening the case - the original ones are ALL crispy. I recommend RWAP's supply for those - they're fresh, well made and of the best, most durable materials.

The only other problem people have is that often the pins on some of the ICs tarnish quite badly. Simply reseating the chips in their sockets breaks the tarnish layer enough to get you going in most cases.

There are some new replacement smaller QL boards likely being made that are shorter but will fit in the original case, which will keep the QL going for many years to come. Faster, too.

Meanwhile, you will want to look for a floppy interface, memory, and maybe a CPU replacement - a Gold Card or SGC is your dream buy.

[RWAP]

You should be OK with this QL for a while - I think it has a new membrane in it already !

The main things to remove to see the PCB are the two molex keyboard connectors, and the set of LED wires (6 in a strip) - although they are a REAL pain to get back in and one will normally come loose as you push down the connector...

You may also wish to remove the heatsink, so that you can get to the motherboard under the heatsink - just one screw which passes through the 7805, a couple of washers, and then the heatsink into a copper pillar below.

I would advise against removing the microdrive cables - they are extraordinarily hard to replace - as they are each connected by two flat ribbons - each ribbon terminates in 7 bare wires which push into sockets below.. Straightening the wires out and keeping them straight when trying to push them back in (whilst holding the microdrive unit in the air) is an almost impossible task - I have used a strip connector before attached to the end of the cables, to make it a bit easier..

[Simon_Carr]

... Well if it ain't broke, don't fix it!

My QL seems to work really well (thanks Rich), so it is right down my list of things to open up and prod around with... I have a very temperamental Issue 2 Spectrum and a Denon Stereo to sort out first.

Many thanks for the top tips with regard to things to look out for, especially the LED and microdrive cables.

Right, back to SuperBASIC..., found myself trying to find DLINE on my Spectrum today

[dilwyn]

Right, back to SuperBASIC..., found myself trying to find DLINE on my Spectrum today

He he, Simon's getting addicted to Superbasic

[1024MAK]

Just to expand on the LED connector. The individual wires from the LEDs go in this connector. The top of the connector then pushes in to grip and make contact. It is NOT a plug and socket arrangement.
When disconnecting make a note of which wire goes where, as you will need this information when reconnecting

Mark

[dilwyn]

Just to expand on the LED connector. The individual wires from the LEDs go in this connector. The top of the connector then pushes in to grip and make contact. It is NOT a plug and socket arrangement.
When disconnecting make a note of which wire goes where, as you will need this information when reconnecting
Mark

Assuming all QLs are the same in this respect, each time I've had to do this, one of the wires always escapes!

[RWAP]

The US Samsung QLs had a proper block connector !!

[skagon]

I would advise against removing the microdrive cables - they are extraordinarily hard to replace - as they are each connected by two flat ribbons - each ribbon terminates in 7 bare wires which push into sockets below.. Straightening the wires out and keeping them straight when trying to push them back in (whilst holding the microdrive unit in the air) is an almost impossible task

Oh, good... it''s not just me, then...
Phew...

- I have used a strip connector before attached to the end of the cables, to make it a bit easier..

Tip: I got some spare 14-pin DIL sockets that I had lying around (for the 74LS series), chopped the plastic that connected the two sides, then got each pin strip, inserted and soldered the wires of the two ribbons one by one in the DIL socket holes and voila! A makeshift connector! And you don't have to change anything, neither on the QL board nor on the microdrive PCB.
Oh yeah, the sockets have to be the nice round ones that look like the wire-wrap sockets, not the ones with the flat pins.
Hope someone finds that useful...