Power jack polarity

[RedDawgEsq]

Hello,

I have an HP/Compaq Mini 110 that was given to me because both the battery and the AC adapter were misplaced. I have a power supply of the correct voltage (19 VDC) and can get a power plug of the correct size. I need to know what the polarity of the plug should be, i.e., is the center of the tip positive or negative? I also need to know if the computer will otherwise power-up if a battery (even a dead one) is not installed. If it will power-up with the correct polarity A/C adapter, I will buy a battery, otherwise I'm not wasting the money. Shame on HP/Compaq for not showing a pictoral of the correct polarity on the case of the device. If I can get it going, does it have enough moxie to upgrade to Windows 10? Thanks.

[Huffer]

These AC adapters, like almost all laptop adapters, are center positive. However, I am going to discourage cobbling together an AC adapter when you can get pretty good ones off amazon.com for way less than $20 that are marketed for your specific model. 

The battery is not needed for power on. 

https://www.amazon.com/1-58amp-Adapter-Charger-Compaq-Mini/dp/B0028LGEYU/ref=sr_1_2?ie=UTF8&qid=1468...

These Intel Atom netbooks were kind of a passing phase. They generally max at 2 gigs of RAM. You could install Windows 10 on it if you install the 2 gigs of memory. Probably would be OK for light internet and email. The XP models likely only have 1 gig of memory and that is not enough for Windows 7 or 10. 

[RedDawgEsq]

Just want to make sure it powers up before spending any appreciable money on it. I have the supply so that's free and the plug will cost me $2. That's all I want to spend unless/until I know it is not DOA. But if it will work, I don't want to fry it by hitting it with reversed polarity power, unless it's designer to accept that. From the sounds of other posts in the forum it's probably not. This should be an easy question. Yes, center tips are USUALLY positive, but I need to know for sure.

[RedDawgEsq]

Yes, I saw the same offering on Amazon, tried enlarging the picture to see if I could make out the diagram showing the polarity but the resolution is not fine enough. It appears the call-out on the left is pointing to the center conductor but I can't tell if it has a + or - sign on it. Does HP/Compaq have a labeling convention/standard for this? I asked about polarity, but so far, no one has answered. 

[Huffer]

I said it is center positive so I did answer. I test these with a multi-meter all the time. You used to see older laptop adapters with a polarity diagram painted on but I think it is well known now they are center positive if it is the old pin type. Most laptops now use one with a center pin inside a larger jack or even other alternate designs as the pin types are prone to being torqued in place and busting the jack inside the laptop. That is why Apple came up with the Mag-Safe thing years back. 

And a lot of times the real point of these posts is not to actually seek information but to display how someone can call "gotcha" and point out some defect. If the convention says that all adapters should have a polarity diagram then yes, HP has stopped doing that and it would be best if they would revive the practice. I agree. And it would be best to do nothing until the President of HP comes on here and publicly apologizes and confirms with a personal guaranty that the polarity is center positive. I can understand and get behind doing nothing until then. I will get to work on it.   

[RedDawgEsq]

I wasn't trying to imply you didn't answer the question. I was hoping, in a best case scenario, there might be a reference to an official  HP/Compaq document that would provide that specification unequivocally.   Since there are (a few) adapters with negative center pins, there apparently devices with that configuration, which is sort of my (semi-overlooked) point: I don't need the polarity of the ADAPTER, I need the polarity of the DEVICE.  i don't think I have ever seen an ADAPTER without such markings, even HP, and even if there are some, they are, as you noted, easily measured with a multi-meter, but I know of no way to MEASURE the polarity of a DEVICE if it is unmarked. Case in point: I have sleep apnea which is treated with a device known as a CPAP machine. If I don't use it when I sleep, I have a small, but non-zero chance of not waking up. Once I went on vacation but neglected to pack the power cord. Fortunately, the voltage AND polarity were molded into the case and I was able to obtain a replacement at a local Radio Shack, with confidence I would not smoke the machine when I plugged it in. A NetBook is not so critical an application, but the solution is so obvious and easy to accomplish, I can't see why it is not routinely implemented. My comments do not constitute a "gotcha" for HP and none was intended; they have plenty of company in this "defect". This is just one of many "common sense" design issues I have with consumer products (mostly tools and automobiles), but "they" never ask me for my input. Go figure.

[Huffer]

I understood exactly what you meant. You need the polarity of the male adapter jack....center positive or center negative. I am an older guy, been doing this a long time and I have had the misfortune to plug in a center negative adapter into a system designed for center positive and smelt the consequences. I have some universal adapters that have a polarity switch. I did look for some kind of spec sheet on the adapter and found nothing. The distinction between the polarity of the device and the polarity of the adapter is hard to figure out as the pin is fixed....there is nothing on the device that can be changed so effectively the polarity of the pin is the polarity of the device. 

30-W UMA AC adapter 496813-001

I did find this English supplier that sells a compatible part and says it is "centre" positive. So there's that. And this one has the universal centre positive marking on the casing of the brick which is what I used to see on just about every one in the day. 

https://www.cougar-extreme.co.uk/components/laptop/hp-mini-charger-30w.html

[RedDawgEsq]

Success! Wiring my supply as center positive allowed the Mini to power up, so I will probably buy a "real" supply and battery as it seems a worthwile machine for a non-power user. The input jac is "touchy" and seems to lose contact easily. I have not yet looked at seeing if it can be tightened up, but this seems to be a weak point of the machine judging from other postings.

While I'm at it, seems like a good idea/time to upgrade the RAM (from 1 GB to 2GB. Is that the max it will take? There is a withering number of selections available and I'm a novice at what all the alphabet soup after "2GB" really means. They all seem to be in the $12-15 range but I don't want to buy something that either will not work or delivers performance I don't need. Any guidance there?

Also, the stock 16 GB SSHDD is essentially useless, so I'll probably replace that so I can upgrade the O/S as well. What is the max size HDD it will accept? Is Win 10 still available as a free upgrade? Thanks for the help.

[Huffer]

Need the exact model number to be 100% sure and get you the correct service manual but as far as I know on the Atom processors 2 gigs is the max. Likely DDR2-533. Single module. The 16 gig SSD can be replaced with a 2.5 inch SATA hard drive but I seem to recall that is going to require a caddy and cable kit. Windows 10 is a free upgrade from licensed Windows 7 Home Premium at the lowest and I think those Minis were originally licensed for XP or Vista Basic so no free upgrade. 

They do run pretty well on Linux. Ubuntu makes a "netbook" edition that actually works very well even on 1 gig of RAM. 

[RedDawgEsq]

From the tag:

Product: Compaq Mini 110

S/N: [personal informatioin removed] 

P/N: VA729UA#ABA

Model #:  CQ Mini 110c-1001NR

FWIW, the present 1GB RAM stick has the markings as shown. 

Also, is it likely I will be able to "tighten up" the power input jack? Are replacements available ar are they of a better design than people have been complaiining about?

The "case" that the SSD is in has what appears to be normal SATA connectors, so I would think a standard SATA HDD would plug right in without any special accommodations. Maximum HDD size it will take? Thanks.