Hoarding Power Blocks

[ChrisGreaves]

(In the absence of a Hoardware Forum ...)
The ACER LCD monitor stopped working about 4 months ago. I assumed it was the monitor. A thought strikes me "ping!":

What if the monitor is OK and it's the power block that's at fault?

Obvious solution: Read the rating off the back of the power block and see if I have a similar block here.

The question: What would be "Similar" for these purposes?

Obviously a 100% match is safe and any discrepancy indicates some risk.

My scanner (no drivers for Win7/64) and monitor blocks are listed below. (I have eight other blocks plugged in around my desk).
Canon Scanner 12V 1.25A
ACER LCD monitor 19V 3.16A

To my mind that's no match. Either I'll under-power the monitor or burn out the block.
The other way I'll burn out the scanner or ...

But suppose the scanner block said "18V 3.1A" or "20V 3.1A", a difference of about 5%.
Would it be safe to plug in, solely for the purposes of seeing if the monitor came to life?

The question suggests that I should keep a table of my power block ratings, and, perhaps, never throw away a block that fills a gap in my table.

I paid $50 for the refurbished monitor about 6 years ago. It has served me well. In this example it would not be the end of the world if I burned it, because it's time for me to buy a new (or two) monitor.

(later) Being the parasite that I am, I would also table my Good Neighbour Patty's power blocks, those of my Good Friend Betty, ... you get the idea.

[viking33]

(In the abscence of a Hoardware Forum ...)
The ACER LCD monitor stopped working about 4 months ago. I assumed it was the monitor. A thought strikes me "ping!":

What if the monitor is OK and it's the power block that's at fault?

Obvious solution: Read the rating off the back of the power block and see if I have a similar block here.

The question: What would be "Similar" for these purposes?

Obviously a 100% match is safe and any discrepancy indicates some risk.

My scanner (no drivers for Win7/64) and monitor blocks are listed below. (I have eight other blocks plugged in around my desk).
Canon Scanner 12V 1.25A
ACER LCD monitor 19V 3.16A

To my mind that's no match. Either I'll under-power the monitor or burn out the block.
The other way I'll burn out the scanner or ...

But suppose the scanner block said "18V 3.1A" or "20V 3.1A", a difference of about 5%.
Would it be safe to plug in, solely for the purposes of seeing if the monitor came to life?

The question suggests that I should keep a table of my power block ratings, and, perhaps, never throw away a block that fills a gap in my table.

I paid $50 for the refurbished monitor about 6 years ago. It has served me well. In this example it would not be the end of the world if I burned it, because it's time for me to buy a new (or two) monitor.

(later) Being the parasite that I am, I would also table my Good Neighbour Patty's power blocks, those of my Good Friend Betty, ... you get the idea.

I'll assume you mean the power supply transformers or "power Bricks" when you say "blocks?"
Voltage must be the SAME.
If it's DC current, the polarity of the plugs must be the SAME. ( of course the type of plugs must be the same )
If the current rating is larger than the old blocks, that's OK. The device will only draw the amount up to it's design rating.
The block must be supplying the proper TYPE of voltage. Some are AC, some are DC. Never interchange AC to DC or vice versa.
BE careful with these ratings. You could well blow out either or both devices with the wrong unit.

[BobH]

Is there some means of testing these transformers and cables using a VOM?

It seems that one could test continuity, voltage, etc. without risking damage to the monitor or other device (if one knows the device spec).

Inquiring minds . . .

[viking33]

Is there some means of testing these transformers and cables using a VOM?

It seems that one could test continuity, voltage, etc. without risking damage to the monitor or other device (if one knows the device spec).

Inquiring minds . . .

USUALLY, they have at least a minimal spec or rating stamped into the plastic on the brick. Voltage [type and amount] ,amperage and sometimes the polarity of the the plug. [negative tip or positive tip] but not always!
Using the guidelines, you could use a volt meter to check voltage and polarity if it's a DC type. Amperage is the big question mark. If it's not stated, I would not chance just plugging it in and tuning for smoke!
My thought would be to not take a chance on it if you aren't SURE what it is.
They are cheap enough these days and certainly much less than the cost of a new scanner or printer or monitor, etc.
Added: you could certainly check continuity of a cable but there is still the chance of it being intermittent by moving the plug end around.

[ChrisGreaves]

I'll assume you mean the power supply transformers or "power Bricks" when you say "blocks?".

Thanks BOB, yes, transformers of "bricks", and thanks too for all your other comments. I'd considered the old AC/DC trick but hadn't thought of polarity for DC.
All in all the likelihood of a good match seems rather remote.
Here is my current list (assembled during yesterday as I recabled my office)

Canon Scanner	12V	1.25A
ACER LCD monitor	19V	3.16A
Comstar external drive	5V	2.00A
Sunny external drive	12V	2.00A
DI604 D-Link Router	12V	1.25A
Motorola SB5100	12V	0.75A
Delta N17908 (Acer netbook)	19V	2.15A

[ChrisGreaves]

They are cheap enough these days and certainly much less than the cost of a new scanner or printer or monitor, etc. Added: you could certainly check continuity of a cable but there is still the chance of it being intermittent by moving the plug end around.

Bob, Thanks too for these thoughts.
I certainly wouldn't have a problem buying a new brick instead of a new monitor - the ACER LCD has served me very well. I was prompted to post by the possibility that it was the brick at fault.
Also, I'd not thought of "wiggling" to see if it is a cable problem. Will do ....

[ChrisGreaves]

Is there some means of testing these transformers and cables using a VOM?

Thanks Bob.
I don't have a voltmeter (I should have one ... hint for Father Christmas).
I have a little flat one-inch diameter orange bulb with two wires which I use for testing to see if a mains wire is live before I go playing with it. It serves only as a binary device (current? yes/no) rather than a quantitative device.

[Leif]

I have a little flat one-inch diameter orange bulb with two wires which I use for testing to see if a mains wire is live before I go playing with it. It serves only as a binary device (current? yes/no) rather than a quantitative device.

Sounds like a Neon lamp - not at all useful for checking low volts.
(They take minimal current, so typically act more as a 'Voltage > 70V' indicator than anything else.)

Cheap DVMs (Digital Volt Meters) are pretty, well, cheap these days. Cheap enough to be given away free with some products. If all you want to do is check voltage, I wouldn't spend more than $10 / £6-7 / €6-7 on one.

[ChrisGreaves]

(They take minimal current, so typically act more as a 'Voltage > 70V' indicator than anything else.)

Agreed. Mine is not a globe (as shown in the Wiki) but more like a piece of plastic from the turn-signal indicator on a car, a lens-like device.

Cheap DVMs (Digital Volt Meters) are pretty, well, cheap these days.

One of those tools that, had I bought one 20 years ago, ...

OK. Off to the hardware store, me.

[BobH]

Here you go Chris.

Digi VOM

[Sundog]

Here is my current list

Great idea to create a mini-database for these blocks/bricks/wall warts! Only thing I would add (as suggested earlier) would be tip dimensions.

<pause for research>

Ugh! At least two different national standards, many many possibilities.

PowerTips.PNG

One breakdown I've seen:

• [ Male | Female ]

• Outside diameter

• Inside diameter

• [Inside | Outside | Tip | Body ] is the positive connector

[ChrisGreaves]

Only thing I would add (as suggested earlier) would be tip dimensions.

Sundog, thanks for the tips (UGH!)

Canon Scanner	12V	1.25A
ACER LCD monitor	19V	3.16A
Comstar external drive	5V	2.00A
Sunny external drive	12V	2.00A
DI604 D-Link Router	12V	1.25A
Motorola SB5100	12V	0.75A
Delta N17908 (Acer netbook)	19V	2.15A
Ktec KSAS0241200200HU (Linda’s External HD)	12v	2.00A
FLY36-5-12	12V;5V	1.5A;1.5A	4-Socket Female Plug
NT (Northen Telecom) AD-2038	16VAC	0.250A
MDT0361205	5V;12V	2.00A;2.00A	4-Socket Female Plug

I was ratting around a spare stationery cupboard and uncovered a box of the bricks. Above is my current roster. I found some 4-in-a-line socket plugs, so I need to go back now and add at least some basic plug descriptions, as you suggested.
Interesting that the Northern Telecom brick specifies VAC, which I take to mean Alternating Current is output.

[ChrisGreaves]

Voltage must be the SAME.
If it's DC current, the polarity of the plugs must be the SAME. ( of course the type of plugs must be the same )
If the current rating is larger than the old blocks, that's OK. The device will only draw the amount up to it's design rating.

Hi again Bob

Well!
Waddyaknow!
After I tore a strip off my ISP (habit!), I discovered that the old DLink Router was "off".
No Power.
The brick is dead.
I know the brick is dead because I plugged in Linda's brick for one second - enough to see the router lights come on.

Now I have got "Linda's external hard drive power block", Output 12v 2.0A, whereas the router block read Output 12v 1.5a.
If I understand you, this combination is going to be OK?

(Disclaimer: I'm seeking no-fault advice here. The router is covered with pre-cambrian fossils, and I'm considering upgrading my ISP modem from 1-socket, cabled, to wireless Real Soon Now. If the DLink router does burn out, it has paid its way handsomely.)

[viking33]

Now I have got "Linda's external hard drive power block", Output 12v 2.0A, whereas the router block read Output 12v 1.5a.
If I understand you, this combination is going to be OK?
-----------------------------------
That should be fine, Chris.
Using a brick with a greater "potential" output in amps or milliamps is OK. The device will only draw whatever current it needs, not what the brick can supply.

[ChrisGreaves]

That should be fine, Chris.

Thanks Bob.
Plugging in .... NOW

Note to Loungers: If I don't get back here, Bob's blown me up!

[viking33]

That should be fine, Chris.

Thanks Bob.
Plugging in .... NOW

Note to Loungers: If I don't get back here, Bob's blown me up!

Earth to Chris, do you copy?

[ChrisGreaves]

Earth to Chris, do you copy?

[ChrisGreaves]

Using a brick with a greater "potential" output in amps or milliamps is OK. The device will only draw whatever current it needs, not what the brick can supply.

Hi Bob.
It sometimes takes a few days for all my synapses to align ...
Got this far. A power brick that can supply more amps than required is OK for the device.

Now, how about a power-brick that is rated less-than the device?

A 1.5A power brick with a 2.0A device.
I presume that the device is cuckoo-like going to demand more power than the power-brick can deliver, so one of two things can happen:
(1) the power-brick fries as it tries to squeeze more electrons through its wires or
(2) the device suffers (dropped bits, reduced amplifier volume, less light etc.) because it's just not able to get enough "fuel".

[StuartR]

...one of two things can happen:
(1) the power-brick fries as it tries to squeeze more electrons through its wires or
(2) the device suffers (dropped bits, reduced amplifier volume, less light etc.) because it's just not able to get enough "fuel".

The most likely result is both of the above.

[ChrisGreaves]

The most likely result is both of the above.

So much for Heisenberg!

Thanks, Stuart.