I've modded my JVC in order to prevent 'Loading' issue...

[tangerine]

... caused by overheat.

Click: http://tangerine.uw.hu/jvc

Any opinions?

[lordsmurf]

I would not want a machine with a fan that runs 24/7. If for no other reason than it's not electrically safe. And are you sure the DR-M20 is a unit known to have this flaw? I don't believe it is.

[tangerine]

I guess it it the same machine as DR MH30 with a smaller HDD.
No problem with 24/7. Two of my computers are running from years with many fans in them. I never poweroff them.
I am more afraid of fire it might cause or accelerated ageing because of the heat. It is extremely hot when standby. When I opened and touched the heatsink it burned my finger.
I can easily buy a new fan/year if needed.

[lordsmurf]

If you need a machine 24/7, I would honestly suggesting owning two, and rotating their use.

[tangerine]

I wouldn't buy another recorder for another 420 € (+50 € for shipping from France)

If it is not restricted to use 7/24 then it can be used 7/24 without any problems.

I am sure about that electronics without moving parts will not damage by normal use at normal temperature (20-30 °C). Only HD and DVD-drive can damage. There are some exceptions, i.e. CRTs. But ICs, resistors, diodes never die.
Well electrolyte capacitors can died by drying out. But they will dry sooner at 70°C (even it is off) that at 30° and on.

What is more it is better using something continuosly than switching on/off.
If always on the temperature stays (more or less) constant. If on and off the termal expansions can cause (sooner or later) contact errors in the connectors or cracks in the solderings.
The more temperature difference between on and off the more chance to get damaged.
Even HDs' lifetime is usually longer if spinning continously.

I think every "durable good" has its "weakest link" in order to limit its life to warranty period+1 day. This is the essence of consumer society. "Throw it away and buy another(newer/better/cooler) one"

I am trying to extend this period to at least 4-5-6 years by proper cooling.

[lordsmurf]

Even HDs' lifetime is usually longer if spinning continously.

Myth.

[spectroelectro]

Actually that's not a myth. Hard drives are prone to something called stiction. The actuator on the servor can get stuck if the drive has spun down. I once repaired an old hard drive back in the mists of time lost before the dawn of the internet by removing the hard drive and whacking it's spindle with a sledgehammer. This jarred the actuator loose and the drive worked fine for many months...until I made the mistake of powering the machine down again. Stiction set it again and the hard drive was toast.

[lordsmurf]

Yes, yes, lots of theory.
But in the end, it's a myth.

The same is said for lightbulbs, tv sets, computers, you name it. But it's just myth with no practical empirical data to support the claims.

Electronics need cooling periods, that is a fact that you can take to the bank, and it contradicts the "leave it on 24/7" myth entirely.

I've dealt with a lot of electronic equipment that runs 24/7, and that stuff breaks more than something that is on/off as needed (within reason, don't be the kid flicking the light switch).

[gshelley61]

Electronics parts (not just capacitors) do wear out and degrade over time from use. They can go out of spec eventually, too. Running gear 24/7 will not extend the service life... it shortens it. Power on / power off cycles are no problem if they are reasonable (once a day, a few times per week, etc.) If you power on something 20 times per day, then yes that could have a negative impact.

It's best to shut down most electronics, including computers, when they are not going to be used for a while.

[trossin]

But ICs, resistors, diodes never die.

Are you are kidding? I made good cash because of this repairing TVs when I was in my late teens. Ever hear of people having to shell out hundreds of dollars for a new engine computer for their car? It happens often.

Devices fail in circuit for many reasons but usually it is due to stupid engineers or management that forces engineers to push devices past their limits. TV sets just barely work. I found a set that drew 950mA that used 1A diodes in the power supply. Every time the set was turned on the surge current exceeded the max spec of the diodes. Over time or due to a slight bump in the line voltage the doides failed as the silicon junctions started breaking down and turned into wires which took out a few other parts.

I believe that there is a trade-off somewhere where it is better to leave a machine running than to power-cycle it often. I use my computer at home every day or two for an hour so I choose to turn it off when I'm not using it. If I were to use it every day for 8 hours like at work, I believe it is better to leave it powered up.

This is also a personal decision. At work we have a sprinkler system in case of fire and I do not sleep there at night. At home I try not to leave my computer running while I'm sleeping as all I have are smoke detectors and I like my house better than the building I work in.

The reason I believe that it is better for the machine to leave it running is that powering up a hunk of silicon is risky business (let the smoke out and your done). The die goes through terrible temperature changes at varying rates across the surface. It is hard as hell to model so nobody really does it. While the clocks and supplies are coming up, both the N and P-FETs in a CMOS circuit can be conducting which effectively shorts the power supply out though some tiny transistors for a very short period of time. Every time you hurt them they can weaken.

My experience is that 10 times more semiconductor devices fail when being turned on then fail while having been powered up for a few minutes. I bet if I really counted up the number of devices that I have failed for me it would be much higher than 10x.

In our high end chip testers (see shameless plug below) we use water block cooling to keep our systems at a constant temperature to improve performance and to improve reliability. They are generally left on and working 24/7/365.

Shameless plug:

http://www.home.agilent.com/USeng/nav/-536886626.0/pc.html

[tangerine]

Maybe you are right. My "problem" is with my JVC is the extreme temperature difference between ON and OFF state. The most funny thing is that it is just the opposite than it expected to be. It is hot when off and handwarm when on. It should be cold (off) and handwarm (on).
I usually record from TV 3-4 times a day that means my JVC will cooled down and heated up 3-4 times a day. I guess this is the worst thing that can happen to electronics. Much better (my opinion) to sacrifice a cooler fan/year and keep it at quite constant temperature.
I guess the car computers' failures are caused the extreme temperatures and temperature changes. Summer/winter and day/night.
One more thing. There is not much diffence between JVC's ON and OFF state. It is almost ON when OFF. I made measurements when OFF and most of the parts is under voltage. At least in the power supply section. So I only added voltage to one more part which is the fan. I am sure that cannot arise any problems.
Most computers with junk chinese power supply set on fire when they are OFF. Why?
I have a thermometer in my PC's power supply. It is 37-40 °C when ON. Two minutes after powering off it rises to about 55 °C. So if I happen to poweroff my computer (only when I go away more than 2 days) I not only power off my comp, but I remove the power plug.
Well it is a bit risky to leave ON beacause of possible fan failure, but latest ATX power supplies have 2 fans and it is very rare that both will break down at the same time.

[FOO]

Electronics need cooling periods, that is a fact that you can take to the bank, and it contradicts the "leave it on 24/7" myth entirely.

Smurf , you are SO entirely full of it. You don't know a thing about electronics , but are willing to make profound pronouncements.

The truth is if you pray over your equipment and sprinkle holy water on it.
it will not fail

[SLK001]

Operating electronics near their max temps is a well known way to shorten their lives. If your recorder is running hot in standbye, then your fan idea is a good one. And quality fans can run constantly for years. But I would have tried to find a 12V ball bearing fan.

[phelix]

I've dealt with a lot of electronic equipment that runs 24/7, and that stuff breaks more than something that is on/off as needed (within reason, don't be the kid flicking the light switch).

And I have equipment that still runs fine after 10+ years of 24/7 operation, and have had more harddrive failures on startup that on machines that run continuously. My pointless anecdotal evidence cancels out your's :P

Instead of arguing who's right or wrong, I'll just expose exactly what fuels this "myth". People notice that things break when you first turn them on. Computers, lightbulbs, etc., seem to have an irritating habit of breaking at the start. THen they conclude that it's better to never turn something off so that you can avoid turing something on (and thus cause it to break).

There are two factors at play in this belief:

• 1. people don't normally keep this stuff on 24/7, so they have no real experience to base their judgement on.
  
  2. Many things experience their greatest stress upon startup. Whether it be fritction/inertia with mechnaical things, or thermal/surge issues with electronics, devices are more prone to failues during startup than in steady-state use. Drive stiction, which has already been mentioned, is a prime example. The simple fact is if something is about to fail, the extra stress incurred at startup may be just enough to trigger breakdown.

So, like with many myths, there is a little half-turth buried in the middle.

The truth is if you pray over your equipment and sprinkle holy water on it.
it will not fail smile.gif

Nonsense. Real Enigneers know that it takes a blood sacrifice to keep things running. That's why so many computer cases have sharp internal edges; to ensure the necessary sacrifices are carried out during assembly.

[lordsmurf]

People notice that things break when you first turn them on. Computers, lightbulbs, etc., seem to have an irritating habit of breaking at the start. THen they conclude that it's better to never turn something off so that you can avoid turing something on (and thus cause it to break).

That's not entirely true either. While this is how a myth starts, and is false logic, it does coincidentally arrive at the same conclusion. So while those people are "wrong" they are also "correct".

[ZAPPER]

Ooh, ooh, ooh! Stupid arguement can I jump in?

Power off and power on do take a toll on any equipment. With the change in tempeture things do actually move and subcome to stress. The light bulb is a good example. When the element heats it expands and when it cools it returns to its normal position although very minor, it is a stress, and stress is what leads to failure. Solder joints are another example of where this stress takes place. How much effect this actually has on things in the real world is probably minimal. I would venture to say that a switch would fail from physical use before a solder joint fails from thermo changes while in the normal operating range. I have seen bad solder before. The example I am talking about was on my GE TV the high voltags board had several connections that when veiwed very close had little black rings around the leads of various components. The fix seems easy, just clean and resolder. I have had two pros and made several attempts myself, but every six months or year or so I am taking the thing apart and fixing something on it.


I would say that adding the fan is a good idea. Properly installed and fused I see no great fire risk, or at least none greater than what you already had. Of course, if your house burns down don't come calling on me. My PC fan seems happy to hum along 24/7 and only if I know that I will be gone for more than a few days does it ever get turned off. (Restarts not included) My answering machine, alarm, sat tv box and a host of other stuff stays on the whole time as well. Eventually everything is gonna die. And then It will be time to upgrade, that's just the way it is.

Keep in mind that I am a lowly carpenter, and would never use a sledge hammer to fix an electronic device (a framming hammer maybe).