The Sinclair QL Forum

Hi Rich !

Thanks for a bit of reassurance on the drives !!, I think cleanliness and storing tapes in a clean environment inside their protective cases makes sense !

I just went ahead and ordered the membrane too as I will prob need it too, I do know old 80's plastic broke down with age regardless of use or not, so prob has broken up due to chemical breakdown etc.

Excellent idea to check chip temps !!! The machine has been running 20 minutes and I used my IR heat gun to measure the chips and the Motorola CPU was at 31 degrees and all other chips between 25-30, the component screwed to the big heatsink on the right was strangely only 25 ?

Ahh just as I spoke 10 min later....the blue screen has came back with a vengeance !!

http://www.mediafire.com/view/dxvim0b4f ... C_0058.JPG#

1 minute after this pic was taken the screen started to "flash" (the pic above was a static pic)

All chips were still cool, the component with the big heatsink was 45 degrees...but I don't think this should be cause for concern ? on the other hand this is a 50% leap in temp ?? so maybe it is like 80 internally ??

Sorry for all these questions, but is there a standard UHF Freq the QL's used so I can make sure my TV is optimally tuned ?...there is a shedload of info on the ZX Spectrum but not so much on the QL on the net

PS have to say at least one thing you QL owners are so lucky about is your machines don't turn brown with age like ALL my old commodores :D:D

PS Thanks to all who have replied I really appreciate it !

Gary

What are you hoping to do with the QL once it's working?

vanpeebles wrote:What are you hoping to do with the QL once it's working?

I'm doing a (free) operating system (just a hobby, won't be big and professional like gnu) for 386(486) AT clones

lol I know Linus Torvalds owned one

I haven't thought that far ahead....what do you recommend ?

Gary

Well the QL can do all kinds, I do a lot of gaming on mine and general tinkering about

vanpeebles wrote:Well the QL can do all kinds, I do a lot of gaming on mine and general tinkering about

Hi Mate, yes play games that sounds good !

I think the reasons I am interested in a Ql are

1) I never owned one but remember them "back in the day" and am curious
2) Micromen not sure how historically accurate it really was, but loved it - watched it everytime I flew to New Zealand on my laptop !
3) I love all 80s computers !
4) Yes tinkering as well, but not to excess
5) It's generally good to preserve and maintain these old girls !
6) I always liked "Sinclair Brand"

*years* ago when I was a kid imagine my excitement when my dad arrived home in his Ford Cortina with a brand new Sinclair C5 on the roofrack !!
Then imagine my utter disappointment when he put it in the garage and it never moved 1 inch since then !!

I have some of the bits in my office and *someday* plan to restore it, here are some pics of the bits to hand

https://www.mediafire.com/folder/fip4s4p84e2e3/C5

So as a kid Sinclair was part of growing up Apologies if this is off topic btw !

So what are the best games, and do I buy them on microdrive tapes ?

Gary

Hi,

SInce you have the QL open, power up the QL and try feeling the chips with your finger.

If the problem is temperature related then the faulty chip will be hotter then the rest.

With regards to the soldering picture for the A600 LED, too much heat on the soldering iron caused this. We all have been there and have overheated components.

I have re-capped some Amigas (A1200, A600, A500, CD32) the CD32 was a funny one with Commodore fitted a electrolytic capacitor the wrong way around, but it did not cause the CD32 to fail.

I never seen capacitor failure on the QL. But it is maybe a good idea to replace the capacitors. As stated they are well over 30 years old.

I have bought some Sinclair computers from a house clearance expert? in Manchester: 2 x QL, 2 Spectrum+, Spectrum +3, all with PSUs. Only one QL, Speccy +3 work, the others need a little work.

I think the QLs just need a clean, as sometimes the plugin chips get oxidised, a clean with a white pencil eraser will clean this up.

It is maybe worth mentioning that QL TV output never was crystal clear and rock-steady, even when the QL was new. The TV modulator has always had a tendency for drift and needed re-tuning of the TV over time. 30 years ago video quality much worse than today was considered "acceptable".

I would definitely recommend to get rid of the TV output completely - Look for a proper SCART or other video cable. If you look through the forum, you will also find mentions and reviews of some video converters that allow to create clear pictures at full QL resolution on today's monitors.

Tobias

If your soldering is as bad as you say, what with burnt track and/or boards, just how big a wattage is your iron I wonder? I've used a 15w Antex for over 30 years (had to buy a new one a few months back, finally) and that does admirably with a 3mm chisel bit. I have other bits too but he default one works for everything, including surface mount.

Some irons available in "cheap shops" in the UK are about 40 or 60w and have conical tips, these are way too hot for electronics work. I've never used a conical tip, but I've heard that they are not all that great.

Also, do you clean the tip? I find dabbing it in a container of brass "wool" works far better than a damp sponge plus you don't get the thermal shock on the tip as it goes from around 260C to whatever the damp sponge leaves it at.

Is your solder flux based or flux free. For electronic work, flux based is best. And don't talk to me about lead free solder. It's almost mandatory in the UK but it's pants. It needs a hotter iron, doesn't wet as well, and has no health benefits over tin/lead at all. Bloody EU rules again. It's the flux fumes that are supposedly harmful, always has been. End rant! I solder in the kitchen with the cooker extractor on full blast.

Finally, you'll be glad to hear, a little dab of new solder on an old joint sometimes helps with unsold ring as well as desoldering. Heat the pad, dab on flux based solder, remove solder wire andvthen remove heat. Then restart after a few cooling seconds and do what needs doing.

Hope his helps reduce burnt boards in future. Soldering really isn't difficult, I've been doing it since I was about 10 years old! Search online for "soldering tutorials" and pick a Raspberry Pi one as these are aimed at getting kids started so should be adequate for all beginners/improves.


Cheers,
Norm.

Hi Norm thanks for the reply !
I think I will invest in a new Quality Iron and practice on some old PC motherboards I have, not sure about the "It's the flux fumes that are supposedly harmful" bit lol oO, I guess I will have to hold my breath and consume copious amounts of beer to counter any potential ill side effects
I think I read somewhere Military and Satellites are still allowed to use lead solder !

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QL Update
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My new membrane (Thanks Rich) and chip and QL to RGB Lead all arrived today \o/

Step 1 - use QL to RBG Lead.........drum roll ..........

PERFECT PICTURE !!! as you can see here

http://www.mediafire.com/view/tg74g82b8 ... C_0075.JPG#

Next step Install the new membrane

Thanks again to all here for your excellent assistance, I really appreciate you sharing your knowledge with me !

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QL Update # 2
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Just out of Curosity I cleaned contacts on old QL membrane ....still not working so removed old membrane ...."looked" in great order...just goes to show eh, the old one is here :

http://www.mediafire.com/view/bxosabcdz ... C_0079.JPG#

So installed the new one...nice and easy and VOILA !!!!

http://www.mediafire.com/view/glxzxm45a ... C_0078.JPG#

So delighted how sharp the image is now