There are a few reasons people buy a cell phone for parts. This guide is for those looking to fix the phone or another like it. A used phone with known issues can be a good cheap source of parts if you have the skills and knowledge to do the repairs. You can AT TIMES save money over buying a used phone, and theres always the pride of a job well done.

Before you start looking for a parts phone:

You need to be sure you know whats involved in the repair of the phone, have the tools, and its a good idea to have either a guide or manual to help get you through the process. There are a number of websites you can Google for poplar phones such as the Razr, Rizr, Iphone, MDA, Blackberry, as well as some being sold cheaply on eBay. There are also toolkits sold here on eBay for many models.

Note on new parts:

Consider that new parts are great, but many non OEM parts will not fit right and not everyone selling OEM parts is selling OEM parts, look hard at that feedback for issues. Some housings are so poorly made they do not fit the phone, others work great. Screens may be poor quality, the colors off, its a long list. With a parts phone you know your getting OEM parts, but if they work is still a valid question.

Checking for a clear ESN IMIE, ect.

Its rather pointless to fix it and then find out its useless. The serial number of the phone your using for parts should be checked to see if its clear with the carrier. Ask the seller for it before bidding and take 5 min to call your carrier. This is really important if you plan to use the mother board of the parts phone in your repair, if its blocked then you may never get the phone to work on the service. Changing the ESN, IMIE is illegal.

The Dot:
The dot in the back of the phone (in the battery area) is water exposure indicator.

White Dot:

If its white the phone has most likely not been water damaged, if its pink or red it has. White dot phones are good for electronic parts, failure to power on is likely a bad mother board or keypad, a nonworking or white display may be a bad flex cable. A number of flip phones route the display flex through the hinge (Razr phones often break at the hinge.) and the flex may strain and break.

Red Dot: Water Damaged phone.

The longer the phone has been wet and power applied the more likely its not going to be a cheap or simple repair. Nor is the dot just being pink any assurance the phone has usable electronics. If the dot is missing consider the phone water damaged.

A wet phone is one huge short circuit, and typically the phone is powered on when it gets wet. Water damaged phones are best used for cosmetic parts, in general case and glass should be use able, the electronics may or may not work. Often you will see what seems a simple and easy fix for a water damaged phone, you can spend more then the phones worth to repair it. In all cases you should never bid high on water damaged phones, they can in some cases be repaired cheaply, but the odds are not with you.

GSM, CDMA, Locked and UnLocked:

If the parts phone is not on your carrier you may not be able to use it for parts. For example a Verizon phone cant be used on Sprint. You need to get the same phone and carrier branding as the one you wish to fix. With a GSM (Sim Card) phone it may be locked to another carrier, you can often have it unlocked, for a fee. Some carriers will re-flash a phone for use on their service, cant hurt to ask before bidding.

Branding and Firmware notes:

Note the type of phone your going to fix, lets use the Razr as an example, its a good one. It comes in a number of types and flavors. The V3, VC3, V3I, V3M, V3T and V3R. Most parts are not interchangeable between revisions, types and models, even on the same model the firmware (Sprint, Metro PCS, Verizon, Virgin, Modelo, ect.) as noted above can stop the repair from working. The V3T sold by Rogers is a V3I, while you can swap its mother board with a V3T from T-Mobile you should not try to flash one firmware to the other and expect a working phone. The same applies to the Itunes and Non Itunes version of the V3I phone, likely you will need to have it reflashed and a PDS repair done. Then there bootloader issues. I killed a Motorola V3I by having Motorola Update do the software upgrade, changing firmware is a risk.  Tracfones are software locked as well as Sim locked, good for parts for another Tracfone, odds are you can get a used working one as cheap.

User Locked: (Not carrier locked)

The user enter a security code into the handset, to use the phone you need to know its code, typically a pin number from 4 to 8 digits long. You may try to guess it, keying in codes for weeks, or you may try Google to see if theres another way to remove it, your carrier may in some cases be able to reset it. Try the default code first, enter 4 to 6 0s or 1234, then 12345, 123456. On some GSM Sim phones the code is stored on the Sim card, on others its in the phone memory. Also reloading the firmware of the phone should remove this sort of lock, this should be done by someone who knows what they are doing.
What shape is it in?:

Its a crap shoot, and as a buyer you need to be aware of everything you can. Condition can tell you a lot about the phone your going to use for parts, or rebuild. Its its seen hard use you can expect there has been much more strain on the keypad and other moving parts then a phone in good shape. That may tell you something about what parts are likely to be usable on the phone.

If it can call out but nothing is on the screen its likely the mother boards good and display may be bad, or the flex cable, but don't count on it.

Someone sat on it and cracked the screen, should be a simple fix. Still the housing may have suffered damage, parts may have been crushed.

The phone boots to a loader, its likely its software is bad and needs to be restored (Very Typical with Motorola phones that have been flashed and had mods done.) You may find someone able to reflash with a box for a fee.

A phone listed as displaying numbers, attempting to call out on its own, doing things on its own, may need a new keypad.

I couldn't fix it. Someone took it apart and couldn't put it together right. Unless they really screwed up you should have working parts, still ask why they took it apart. If it was a housing change you may find things in better shape then it if it was acting funny. If they got it on eBay as a fixer and tinkered you don't know what they did and may not have anything useful except the housing, if that.

I drove the car over it, the dog chewed it, it was shot (I've seen 3 or 4 of these.) Back slowly away from the ad, odds are its junk.

I found it. Again back slowly away from the ad. If you buy the phone you can be charged with receiving stolen goods, it has happened. On top of that it may be blocked and unusable on the network. Moral judgments aside Why take a risk?

Blocked, Can't be activated, Not a clear Serial Number: Sometimes these can be cleared, the phone reflashed for use on another network, ect. You may find the old owner has not paid their bill, you want the phone working you can pay it off. You may be able to use it on another network. A fully working phone is great, you know the parts you need work, and a simple mother board swap may get you up and running. Not really a phone you want to buy to use its mother board as parts, if you can get it cleared why not use it? If not the motherboards not of any use other parts still are.

Gets hot: May be a bad charger port, battery, or mother board.

Not charging: Ask if the charger port is loose. If it is check to see if you can get a new one, how much of a pain it is to replace. Most Mini USB ports are fairly easy, some are a right pain. It could also be a bad motherboard.

Can't read the Sim card (GSM phones) maybe a bad sim contact, the shim holding the card may be weak and not pressing it firmly to the contacts, could be a bad mother board. Might need a reflash.

Biding:

Ok you found a parts phone you think may fix your phone, but whats it worth? Thats a good question, as a rule its worth about 80% of the cost of the parts you need to repair your phone, or up to 30% of the value of a used phone thats working. Some people will bid them up and up thinking to get a easy fix, its better to wait.

Its all Junk.

Some are. I got one that every part in the phone was useless and the case was beaten up. It happens, not much you can do but ask for a refund and not expect to get one. You can bet the ad says as is.