Some of you who have never encountered heating problems with your QL before, might discover that about August 15, or the hottest day of the year, that your QL will suddenly blank out. Actually, it is not quite so “suddenly”. There are usually small warning signals like a ripple on the screen or the colors may start to “swim”. Unless you don’t mind losing your data, once you observe these symptoms, it is best to quickly save your data, and turn the QL off for an hour or two.
If you take some of the precautions in this article to heart, there is a good chance that you will never have to worry about the heat problem. Indeed, if you are running an unexpanded QL, without disk drives, or additional memory, heat build up may be so minimal that you will never encounter any problem at all. However, add a disk drive, and you may run into problems.
Even if you do not currently have a heat problem, remember that any heat, over time, is the number one killer of all electronics. Static zaps a few, but heat kills all chips sooner or later. Keeping your QL cool can expand its life.
Rather than starting with the most complex fixes first, I think it wise to attempt to correct the problem with the smallest fix first. If that fails, then move on to more elaborate repairs. So lets begin “outside” the QL.
The first thing to do is, if your QL is not plugged into a quality surge protector, PLUG IT INTO ONE NOW! When doing so, make sure that the power cable running from the surge protector to the QL is not on any carpeting, nor is close to your monitor, or any potential source of static. As an additional benefit, should the power company decide to mess up your power, as they did mine, your QL should be protected. (My power company sent surges through my house that blew over 15 of my appliances including the refrigerator, intercomms, radios, a VCR, the furnace and other goodies. But, although my surge protector was burned, and no longer functional, my QL and disk drives were untouched.)
Secondly, get to know the ventilation system on your QL. If you look at the right side, just below the microdrive ports, you will notice a small line of openings. Beside being the speaker port, these openings permit the inflow of air that is supposed to flow over the heatsink, and exit on top at the rear. Noting that a convection flow of this size has, at best, minimal cooling capacity, NEVER PUT ANYTHING ON THE RIGHT TOP OF THE QL. In a few tests I have made, one single sheet of #20 Bond placed over the microdrives, raised the internal temperature 18 degrees. It not only insulated the top of the case, it prevented the proper convection flow.
If you have done the first two things, and still encounter heat problems, there is a good possibility that the problem can still be solved for about $20.00, without opening the QL case. Run down to Radio Shack, buy a 3″ brushless 9VDC fan (part #273-243). They list for $14.95, but have been on sale recently for $11.88. This fan operates on 7 to 13.8 VDC and supplies 27 CFM airflow. Then add a 9 volt power supply (part #277-1026) for about $4.95, and any switch you wish (less than $1.00), and you’ve got a system that should solve all your problems.
Hook the fan, through the switch to the power supply. Place it on your desk behind the QL, aimed at the right side heat vent. Before you turn it on, feel the cover over the microdrives. Turn on your fan and wait about five minutes and feel the microdrive cover again. It should now be cool to the touch.
While we are forcing the air in a reverse pattern to the normal convection designed with the QL, the flow is sufficient to really cool the QL, and possibly you as well. Remember that if you aim the fan at the front of the QL, you may be forcing dust into the microdrive ports, which could create more problems than overheating.
I put one of these fans on line and put it through a few tests. With the computer on, but idle, the internal temperature in the microdrive port was 104 degrees. After the fan had been running for five minutes, the temperature had dropped to 68 degrees. I then wrote a program to format a microdrive 15 times, and measured the temperature during the format (drives running create heat). On the 15th format, the internal temperature was still 73 degrees.
I have been advised that RMG Enterprises of Oregon City, OR is in the design phase of a cooling fan system designed specifically for the QL, and should run from the QL’s internal power. So, in the future, there may be a system more efficient than this simple one. In the meantime, this seems to be all that is available.
So far, we have found some simple ways to keep a QOOL QL without resorting to opening the case and fiddling around with the insides. If all these have failed, and ONLY IF ALL THESE HAVE FAILED, then we are forced to open up the QL and begin to tackle the problem other ways.
The QL uses a one amp 7805 voltage regulator (you will see it attached to the heat sink behind the microdrives). Since the voltage regularo is heat protected (if it overheats, it shuts down), this, while maybe not the cause of the problem, is certainly the heart of the problem.
The important thing to remember is that simple metal to metal contact is just not an efficient heat transfer system. Metal must be somehow “bonded” to the heatsink if heat is to transfer properly. At assembly, many QLs suffered the same fates. The heatsink compound used was of a type that dries and ages with heat, and in adequate amounts of the compound were used. As a consequence, the unfortunate voltage regulator is unable to transfer its heat to the heatsink.
Fortunately, for us, the fix is simple. Remove the heatsink from the voltage regulator. Scrape off any old heatsink compound, and clean both surfaces as much as posssible. Put a generous coat of any silicone based (it doesn’t dry or crack) heatsink compound on the voltage regulator where it contacts the heatsink and reconnect the two. This increase of thermal transfer will permit the heat to flow to the fins of the heatsink, where your fan can efficiently carry the heat away.
Now, even if you’re running 640K and three disk drives, you should have no heating problem. But, if you continue to encounter problems, there is an additional hardware fix published previously in QUANTUM LEVELS (Vol 1, No 2) by Tom Woods. I don’t recommend that you attempt this fix unless all else has failed. It involves installing an additional 7805 voltage regulator, a capacitor and a diode to attempt solve the problem. The single case that I know of that tried this method was unsuccessul, probably because the simpler fixes, like a power surge protector were not attempted first.
If you wish further information on the final hardware fix, I suggest you contact Tom Woods at Quantum Levels, PO Box 64, Jefferson, NH 03583.
Common sense however, demands that I state, if you have done all outlined procedure, short of the hardware fix, and you continue to have heat problem, you would be well advised to contact A+ Computer Response and get a replacement Q L. If the fan and heatsink compound don’t work, you may have serious problem. Historically, A+ has not been really prompt in replacing defective QL’s (eight weeks is about standard), but right now, we users seem stuck with that situation.
It may be possible that your QL dealer can provide a temporary “back-up” QL for your use while yours is at A+ for evaluation.
As a final thought, (seems like I’m talking to my kid, now) I must stress the importance of cleanlinesss. Dust blocked vents cannot do their job properly. It may appear insignificant, but dust does inhibit air flow essential to cooling. It also has great insulating properties.
Here’s hoping your QL is as QOOL as mine (knock on wood).