Print is light

If you have replaced multiple components in your Brother 8510 printer, including the oven unit, laser unit, high voltage board, power board, and drum unit, but are still experiencing faded images, there are a few other potential causes and solutions to consider:
1. Toner Cartridge: Ensure that you are using a genuine and compatible toner cartridge for your Brother 8510. Low-quality or incompatible toner cartridges can result in poor print quality. Try replacing the toner cartridge with a new, genuine Brother cartridge to see if it resolves the issue.
2. Toner Density Settings: Check the toner density settings in the printer's software or control panel. If the density is set too low, it can result in faded or light printouts. Increase the toner density setting to see if it improves the print quality.
3. Cleaning the Corona Wire: The corona wire is responsible for transferring the toner to the paper. If it is dirty or contaminated, it can cause faded prints. Consult your printer's manual for instructions on how to clean the corona wire properly. Be careful when handling the corona wire as it is delicate.
4. Print Settings: Check the print settings on your computer or within the printer's software. Ensure that you are using the appropriate print quality settings and that any power-saving modes are disabled. Adjusting the print settings to a higher quality mode can enhance the print quality.
5. Contact Brother Support: If you have exhausted all the troubleshooting steps and the issue persists, it may be beneficial to reach out to Brother customer support or a qualified printer technician. They can provide further guidance or arrange for a professional inspection and repair of your printer.
Remember to follow the manufacturer's guidelines and safety precautions when working with printers and their components.

If u have the CD of tht printer , u just delet tht printer from the Devices and printers settings. And re installed it

When replacing the toner cartridge, you MUST install a brand new, unused genuine Brother toner cartridge in order to reset the toner status. Swapping toner cartridges from one machine to another or installing a partially used toner cartridge may cause this problem. Brother machines control their image quality for the most suitable print quality by monitoring toner consumption. If you install a partially used toner cartridge, your Brother machine is unable to recognize toner consumption correctly which will cause this problem. Therefore, when you replace the toner cartridge, please use a brand new toner cartridge, not a partially used toner cartridge from another machine.

Some Brother laser printers have separate consumables - the toner cartridge and the drum unit. From time to time you may need to replace only the drum unit and not the toner cartridge.

The error LED lights up, or an error message shows on a flat screen panel, when the drum unit is near the end of its working life. Use the drum unit until you have a print quality problem, then replace the drum unit with a new one.

There is a reset gear in the cartridge that needs to be "reset" or replaced. I've included a link to a PDF file that goes over the procedure to properly refill and reset the toner cartridge. This is a document that is used by a company that does a complete rebuild, so you probably won't need most of the information, just the part on resetting the reset gear.

http://www.uninetimaging.com/downloads/technical/TecArtWebAdded/Brother_HL_5300_Series_tn650_Reman_Eng.pdf

Try:

Brother strongly recommends that customers use only genuine Brother drum units and/or toner cartridges. Each Brother laser printer is designed to work at pre-set temperatures that are matched exactly to each of our individual toner formulations. Each individual component is designed to work with the other to ensure quality and reliability. Using non-Brother supplies may affect the hardware performance, print quality and machine reliability. The Brother limited warranty does not apply to any problem that is caused by the use of third party drum units, toner cartridges or toner.

For LIGHT print continue to STEP 1.

For BLURRY, VERTICAL or HORIZONTAL LINES, SMUDGES OR DOTS continue to STEP 4.

1. Check the Toner Save setting. If this setting is programmed on, all printed documents will be light.

a. Press MENU, 1 (General setup), 6 (Ecology), 1 (Toner Save).

b. Press the UP OR DOWN ARROW key until the display reads "Toner Save: OFF".

c. Press OK.

d. Press STOP/EXIT.

e. If the setting was changed from ON to OFF print the User Settings list by pressing the REPORTS key and then 5 (User Settings).

turn off printer, remove cartridge and drum and clean internally.
reinstall drum and cartridge and do a test print, hopefully all will be better.

sounds like a bad drumbur also can be caused by a defective fuser.

minolta printers work on "chips" if the chip atached to the cartridge is not original minolta you better change it.