Reply With QuoteDont select the "restore factory defaults" on the remote control menu.
don't put a DM in a holiday house.
How not to 'blow' your DM - a useful guide ...
Having some firsthand experience with 'non functioning' DM's ... I thought it would be useful to start a thread that would detail other member's experiences with their DM's and what they did to 'kill' them ...
... sounds odd to ask for information about what killed your box ... but the idea is that we will NOT do this ourselves ... and avoid the resultant problems ...
We, of cause can put a 'spin' on this and simply say DON'T do (what I did) this to your box ....
I will start with a few useful suggestions ...
1. Always power-down your DM when connecting ANY cables to it - this can be even the scart sockets and video leads - not just the LNB cable. The reason being is that if the 'other side' of your connection is at a different potential and your DM is powered-on it will most likely discharge via your DM's circuitry and not necessarily the GND - because of the nature of the DM's PSU which is NOT grounded.
2. NEVER pull the plug on a DM70xx whilst its powered-up. Use the power switch on the rear to turn 'off' first - then remove the power cord. Pulling a power cord on ANY active appliance which has a high inductance (electric heater has VERY high inductance) will generate a massive electric field (1000's of volts) that will need to discharge somewhere - usually through your circuit board. The field or back EMF will usually be active for milliseconds - but long enough to 'blow' some sensitive components.
For those of you that are not familiar with this phenomena (laws of physics) - you might remember sometimes pulling the power cord from the 240V socket whilst an electric heater is still 'on' - you would have seen a BIG spark at the socket. Believe it or not - the faster you 'pull' the plug - the greater the 'spark'. For those technical - this is caused by a collapsing magnetic field - the faster the 'pull' the faster it collapses - and the greater the spark. With a heater it does not matter - with electronic equipment (any) it does and can kill your device.
3. EARTH your LNB cable - the outer connector (obviously) - reason as explained in 1 above.
4. Don't plug-in any other connections into the LNB input other than a properly configured LNB. Some people who have cable - think that there is no harm in connecting the cable coax connector (it has same fitting and look same) - to see if it works - WRONG. A satellite receiver is designed to work with LNB's and as a result provides 14-18V through its coax to power the LNB. If this connection is 'shorted' or connected to a high impedance - as might be the case when connecting to a cable TV socket (it has totally different termination and function to that of an LNB which the DM expects to 'see') the you most certainly will 'blow' something in your DM
... and another point - but this one is with a pinch of 'salt' ...
DON'T lend you DM to a 'Wally' (a UK term for an idiot) - there is a VERY high probability that the 'Wally' will execute one (if not all) of the above points - the ones that we should NOT do ... and then return the DM claiming they 'did nothing' other than switch it on - and it did not work
... anyway ... I hope that this is a good start for what should be a useful thread to us all ...
PLEASE try to keep this serious ... I know that many of you will be unable to resist for the odd bit of humour when it comes to what to do / what not to do with your DM ... but maybe we can save this for another thread - this one will ONLY be useful to us if we are serious
Cheers
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Dont select the "restore factory defaults" on the remote control menu.
don't put a DM in a holiday house.
never pull cable when flashing - be patient
that is serial, lan or power
[humuor on]
never ever play golf in a lightning storm with your DM
[/humour off]
[QUOTE=z80;42567]Dont select the "restore factory defaults" on the remote control menu.
How come ???
Originally Posted by xlrate
Try it and see....
[QUOTE=xlrate;42611]Because you will lose your settings and you will have to sart all over again
Tagg
So where is the power switch on a DM7000 exactly? And i would suggest shutting the unit down (via menu) first before any power removal. No wonder you have issues with dead Dm's.
And since when is the DM7xx an inductive load? Do you even know what an inductive load is? And when has a heater ever been an inductive load? A heater is a resistive load. And the faster you pull the lead etc etc... WTF!!! You're farking joking right? Didn't you say you wanted to keep this serious?
Keep off the weed and the Sci Fi channel.
If you want to understand what an inductive load is, google Power Facter and Power Factor Correction.
Then come back and give us a lesson on Capacitive Reactance.
And after reading your suggested list of what not to do, it's no wonder you are the owner of some cooked DM's.... Whom would do any of the above in the first place? Clearly some people don't read the Owners Manual............
I have an important suggestion for reliability of any model DM.
Stop flashing the bloody thing.
So does it matter then if you multiple images in a Flashwizard set up?
Or do you mean serial flashing only? Or any flashing at all?
Just interested
Flashing in its strictest sense would be replacing the image in flash memory.
Storing, deleting or replacing images on a CF, USB or HDD over IP might be termed flashing
- but I suspect that the dangers involved in a real flash flash are much worse.
Hell you can always pull out the USB, CF or HDD and away you go on flash memory
Disclaimer: all opinions expressed within are those of the writer and not necessarily those of a sane man
Last edited by nfnovice; 02-05-08 at 11:08 AM. Reason: typo
flashing
Dont manually flash (dm's tmp directory, not through dreamup or Null) from gem to say iolite because of the Max Var difference.
You will think your DM is blown and then introduce a hammer to it. Trust me it wont turn on again.
Thanks nfnovice, yes a bit of a brain fade on my part there re images in flashwizad.
I guess z80 is saying you have more change of corupting something on the interenal flash, the more you flash it
I just thought he may of meant connecting serial cables etc.
So to be more correct, you are only talking about the DM500 here, yes?
Dm500
yes my experiences with this have been with the Dm500s
Dont know with other models...maybe someone can expand on this?
DM500 have less on board memory
... hey sorry if some of my comments upset you ... that was not their intention
In the context of this forum - you always tread a fine line as to how much detail you provide in a post and how much should you rely on the reader’s common sense in reading between the lines ...
Perhaps I should have tried to include a little more details so as not to add confusion
I'll try to clarify some things ...
my comment ... NEVER pull the plug on a DM70xx ... was aimed at the generic range ... if the 7000 has no switch - then of cause you cannot use it ... but the 7020 and 7025 do have switches ...
You are absolutely correct in ensuring that you cycle down the DM via its internal menu to an 'off' state BEFORE switching off the power ... again this is implied and you rightfully picked this up ... I hope others will also ...
... Yes I have issue with dead DM's - because I'm trying to help those less fortunate who happen to have a dead or faulty DM and try to 'fix' the unit for them (because I enjoy doing it) ... they are not my DM's ... I only own a DM500s which had a faulty serial port - that drove me crazy because I refused to believe it was faulty .. fortunately the seller (from this forum) was kind enough to alert me to this fact and swapped the unit for a 'working' serial port DM500s - since then that device has been working 100% - and I have taken all the precautions - like EARTHING the LNB ... and I don't fiddle with it ... it has a working image (happens to be PLi) and I am happy
All devices with wire 'coils' which can create magnetic fields are in effect inductive.
Yes I know what and inductive load is ... there are many variants .. there are complex impedances and pure inductors ... either way ... to an observer looking at the input terminals there is always some form of inductive load which may be frequency dependant. A DM switch mode PSU has lots of inductors - that are fundamental to its operation.
However, since current flow through an inductor cannot change instantaneously, a back EMF is generated across the inductive load, which causes the voltage across the inductive load to rise rapidly. This rapid rise in voltage (i.e., a voltage spike) may cause an arc to traverse across unprotected circuitry.
In the case of a DM PSU - there is no built-in 'arc' protection because it does not occur in its normal mode of operation. And at the terminals - the coils are isolated from the supply via a diode bridge circuit and the diodes will take any of the brunt from the back EMF if it occurs.
If we 'pull the power' under load - there is an undue loading on the diodes and sometimes the high voltage transients can 'break' the diode. It is therefore always advisable that the PSU is cycled down BEFORE cutting power - the load is reduced and so are any knock-on effects as the power is finally 'cut'.
Any heater which has a 'coil' - the heating element - always appears as an inductive load to the supply terminals - but yes - it is of cause a resistive load as well - otherwise we would not get any 'heat' as the current flows through the highly resistive element wire. I guess any wire which has a current flowing through it and there is a magnetic field created can be considered as an inductor and will exhibit a back EMF when the current flowing through it is broken or stopped - because current flow through an inductor cannot change instantaneously - so when the current is removed - the collapsing magnetic field tries to maintain the current - for a tiny moment (because it can’t for ever as there is no energy – only that in the collapsing magnetic field) - causing the high voltage which often discharges as a spark at the plug (in regard to an electric heater). Modern elecrtric heater s most likely have some sort of protective circuitry for this effect - usually a capacitor which absorbs most of the charge.
An 'old' electric heater with a 'glow' element - when you pull the plug at the wall whilst it’s 'on' will always yield a spark at the plug. The faster you pull the power cord - the faster the electric field collapses - and because we cannot change current flow instantaneously - to counter this we get a higher voltage and bigger spark at the terminals.
Automotive 'coils' work on same principal to generate high voltages.
If you want to see this effect get an old electric heater (old because the old ones did not have any back EMF protection circuitry) - switch it on it max wattage and then rapidly pull the power plug out of the wall socket ...
First point ... I am NOT the owner of the 'cooked' DMs - they don't belong to me - I volunteered to help those who have cooked their boxed ... Yes most of them did these stupid things on my list ... and YES again, they did not read the owner’s manual ... so you are correct on both these points ... BUT ... even if they did ... most of them would not really understand ... hence the question ... how did they end up with a DM?
... I don't know the answer to this ... but it may have something to do with their desire to have FREE TV and not understanding much of the things they read on this and other forums
... once again sorry if my guide sounded like Sci-Fi ... it certainly was not my intention
Cheers
Another tip for DM500s owners...Do not connect your coax/lnb until you have set the correct setting 10700, 11300 or universal.
Thanks for that SatXpress, can you please advise why not, as I have never come across this tip before
Why?
It is a hobby so mileage varies
Loving IPTV with XBMC and android M8
Join in the XBMCHUB community and visit me at http://tvaddons.ag/
Yes and not just Gemini - what he meant to say was any max-var image. You can only upgrade from a max-var image to a non max-var (any type) with a flash ease which is done in dreamUP for instance.
It is a hobby so mileage varies
Loving IPTV with XBMC and android M8
Join in the XBMCHUB community and visit me at http://tvaddons.ag/
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