[Ql-Users] Feeding your microdrive...
Hi all, During my time at Sandy, I learned microdrives (the part inside the case, not the cartridge) were surprisingly reliable and fault-free. The only two faults that came up on a regular basis were dirt, and damaged capstans. The capstan, for those not in the know) is the rubber wheel on the motor which contacts the tape. The microdrive capstan has one advantage over capstans from tape decks. Tape deck capstans contact a metal pin when in position. If left for a long time, the capstan rubber acquires a dent which makes the tape change speed as it passed through - also, it slightly stretches the tape. The microdrive design contacts a plastic wheel in the cartridge, so it only touches something when a cartridge is left in. However, some people leave a cartridge permanently in the drive when not in use, and this can cause problems eventually. The wires that enter the motherboard are just tinned stranded wire and quite fragile. I always soldered pins on these as a first act of owning a QL - often, soldering on the pins was quicker than trying to fit that floppy mess of bent wire. I have tons of these pins so if anyone wants some for their QL, I'll happily mail them at no charge. At Sandy, we also found that cartridges would become error prone if not spun once in a while. I got into the practice of, once a month or two, spinning up every cartridge through at least one full loop (about 20-30 seconds) just to prevent print-through and to redistribute the lubricant. You'd be amazed how often we'd get mad microdrive complaints and we'd ask them to send in the computer and the problem cartridges, and they'd ALWAYS have fingerprints, or the computer smelled of cigarettes. Smoking kills cartridges! So does finger grease. If you pen your case to clean anything, it's always a good idea to remove and refit the voltage regulator. That's the small 3-pin device screwed to the heatsink right behind the microdrives. It gets warm regulating the voltage, but a poor connection can also create heat, so reseating the regulator in its socket helps it stay cool. While you're at it, if you have any PC thermal paste/crease/arctic silver, replace that little plastic shim, if there is one, with a tiny dab of that and you'll find it transfers heat to the heatsink FAR better. SOME people would get a tiny fan, hook it across the +9v and ground pins, and have it draw that air out the slots at the back. Nice if you can make it fit, but I don't think it makes much difference - it moves heat, but doesn't make sure it's being generated efficiently in the first place - just addresses the symptom. If I ever designed a QL PCB, it would have a far better power supply (but then, the PCB wouldn't be long and thin like that - it would be a eurocard or double eurocard - 100x160mm or so. I would also give it a proper bus with 4 or 5 expansion sockets. Hindsight. I know this is obvious to many, but not to all, so my apologies to those who consider this obvious. Dave ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Feeding your microdrive...
Plastic wrote, on 8/Feb/11 22:30 | Feb8: Hi all, During my time at Sandy, I learned microdrives (the part inside the case, not the cartridge) were surprisingly reliable and fault-free. The only two faults that came up on a regular basis were dirt, and damaged capstans. The capstan, for those not in the know) is the rubber wheel on the motor which contacts the tape. The microdrive capstan has one advantage over capstans from tape decks. Tape deck capstans contact a metal pin when in position. If left for a long time, the capstan rubber acquires a dent which makes the tape change speed as it passed through - also, it slightly stretches the tape. The microdrive design contacts a plastic wheel in the cartridge, so it only touches something when a cartridge is left in. However, some people leave a cartridge permanently in the drive when not in use, and this can cause problems eventually. I found a large number of QLs I repaired had migrating capstans. They had nothing other than friction to hold them onto the metal shaft, and they rose up in the majority. Maybe the ones that didn't had unused microdrives! In extreme cases the capstan actually touched the top case - I saw many like this. The wires that enter the motherboard are just tinned stranded wire and quite fragile. I always soldered pins on these as a first act of owning a QL - often, soldering on the pins was quicker than trying to fit that floppy mess of bent wire. I have tons of these pins so if anyone wants some for their QL, I'll happily mail them at no charge. If I had to remove microdrives, I always did this. Better than pins though is a SIL socket strip. I cut sections off a DIL turned pin socket. That way re-fitting is a doddle. At Sandy, we also found that cartridges would become error prone if not spun once in a while. I got into the practice of, once a month or two, spinning up every cartridge through at least one full loop (about 20-30 seconds) just to prevent print-through and to redistribute the lubricant. You'd be amazed how often we'd get mad microdrive complaints and we'd ask them to send in the computer and the problem cartridges, and they'd ALWAYS have fingerprints, or the computer smelled of cigarettes. Smoking kills cartridges! So does finger grease. If you pen your case to clean anything, or even 'open'. You are coming up with some brilliant mistypes, Dave. Wasn't it you who talked about 'dinky cars'? it's always a good idea to remove and refit the voltage regulator. That's the small 3-pin device screwed to the heatsink right behind the microdrives. It gets warm regulating the voltage, but a poor connection can also create heat, so reseating the regulator in its socket helps it stay cool. While you're at it, if you have any PC thermal paste/crease/ and another good mistype (8-)# arctic silver, replace that little plastic shim, if there is one, with a tiny dab of that and you'll find it transfers heat to the heatsink FAR better. Yes indeed. I did that to *every* QL I repaired. SOME people would get a tiny fan, hook it across the +9v and ground pins, and have it draw that air out the slots at the back. Nice if you can make it fit, but I don't think it makes much difference - it moves heat, but doesn't make sure it's being generated efficiently in the first place - just addresses the symptom. If I ever designed a QL PCB, it would have a far better power supply (but then, the PCB wouldn't be long and thin like that - it would be a eurocard or double eurocard - 100x160mm or so. I would also give it a proper bus with 4 or 5 expansion sockets. Hindsight. ... and not require the wire connection 5v rail mod that Sinclair added to issue 5 boards! I know this is obvious to many, but not to all, so my apologies to those who consider this obvious. Always worth repeating good advice. You will be amazed at how many still don't know. Tony -- QBBS (QL fido BBS 2:257/67) +44(0)1442-828255 t...@firshman.co.uk http://firshman.co.uk Voice: +44(0)1442-828254 Fax: +44(0)1442-828255 Skype: tonyfirshman TF Services, 29 Longfield Road, TRING, Herts, HP23 4DG ___ QL-Users Mailing List http://www.q-v-d.demon.co.uk/smsqe.htm
Re: [Ql-Users] Feeding your microdrive...
On Tue, Feb 8, 2011 at 5:03 PM, Tony Firshman t...@firshman.co.uk wrote: Plastic wrote, on 8/Feb/11 22:30 | Feb8: Hi all, During my time at Sandy, I learned microdrives (the part inside the case, not the cartridge) were surprisingly reliable and fault-free. The only two faults that came up on a regular basis were dirt, and damaged capstans. The capstan, for those not in the know) is the rubber wheel on the motor which contacts the tape. The microdrive capstan has one advantage over capstans from tape decks. Tape deck capstans contact a metal pin when in position. If left for a long time, the capstan rubber acquires a dent which makes the tape change speed as it passed through - also, it slightly stretches the tape. The microdrive design contacts a plastic wheel in the cartridge, so it only touches something when a cartridge is left in. However, some people leave a cartridge permanently in the drive when not in use, and this can cause problems eventually. I found a large number of QLs I repaired had migrating capstans. They had nothing other than friction to hold them onto the metal shaft, and they rose up in the majority. Maybe the ones that didn't had unused microdrives! In extreme cases the capstan actually touched the top case - I saw many like this. I did see that often. If you pulled the capstan off, and rubbed the motor shaft with a little rubbing alcohol to degrease it, the capstan was far less prone to sliding up. Also, it should be put on upside down afterward - it may have warn slightly unevenly and if so, it needs to spend the next interval wearing unevenly the opposite way - like rotating your tires. The wires that enter the motherboard are just tinned stranded wire and quite fragile. I always soldered pins on these as a first act of owning a QL - often, soldering on the pins was quicker than trying to fit that floppy mess of bent wire. I have tons of these pins so if anyone wants some for their QL, I'll happily mail them at no charge. If I had to remove microdrives, I always did this. Better than pins though is a SIL socket strip. I cut sections off a DIL turned pin socket. That way re-fitting is a doddle. What I have is the single rows of turned pins that we used to use on the SuperQBoard for the riser 512k memory daughter card. They're like a pre-cut sockets of very high quality. They used turned pins on all the boards I saw until I saw a US QL with the flat blade type socket - ick. At Sandy, we also found that cartridges would become error prone if not spun once in a while. I got into the practice of, once a month or two, spinning up every cartridge through at least one full loop (about 20-30 seconds) just to prevent print-through and to redistribute the lubricant. You'd be amazed how often we'd get mad microdrive complaints and we'd ask them to send in the computer and the problem cartridges, and they'd ALWAYS have fingerprints, or the computer smelled of cigarettes. Smoking kills cartridges! So does finger grease. If you pen your case to clean anything, or even 'open'. You are coming up with some brilliant mistypes, Dave. Wasn't it you who talked about 'dinky cars'? Sorry :) My hands are a little numb still and don't co-ordinate very well, and my eyes don't spot the missing letters. it's always a good idea to remove and refit the voltage regulator. That's the small 3-pin device screwed to the heatsink right behind the microdrives. It gets warm regulating the voltage, but a poor connection can also create heat, so reseating the regulator in its socket helps it stay cool. While you're at it, if you have any PC thermal paste/crease/ and another good mistype (8-)# arctic silver, replace that little plastic shim, if there is one, with a tiny dab of that and you'll find it transfers heat to the heatsink FAR better. Yes indeed. I did that to *every* QL I repaired. I'm thinking that by now a lot of the regulators and IC pins will be quite oxidized and could use a good cleaning. I use a PEN eraser to gently remove the oxide. Pen erasers don't generate static charge when rubbed. ICs do run a little cooler when they have good socket connections. One, the socket to pin contact has lower resistance. Two, better contact conducts heat away into the PCB slightly better. Additionally, a cooler IC draws less current than a hotter IC anyway, so it could make 20-30ma each difference on the 68008 or the copro. SOME people would get a tiny fan, hook it across the +9v and ground pins, and have it draw that air out the slots at the back. Nice if you can make it fit, but I don't think it makes much difference - it moves heat, but doesn't make sure it's being generated efficiently in the first place - just addresses the symptom. If I ever designed a QL PCB, it would have a far better power supply (but then, the PCB wouldn't be long and thin like that - it would be a eurocard or double eurocard -
