REPAIRING AND NOT THROWING AWAY

Richtige Fernseher haben Röhren!

Richtige Fernseher haben Röhren!

In Brief: On this site you will find pictures and technical information about Service Modes, Circuit Diagrams, Firmware Update procedure, Disassemble procedure, Universal remote control set-up codes, Troubleshooting and more....

If you go into the profession, you will obtain or have access to a variety of tech tips databases HERE IT IS Master Electronics Repair !.

These are an excellent investment where the saying: 'time-is-money' rules. However, to learn, you need to develop a general troubleshooting approach - a logical, methodical, method of narrowing down the problem. A tech tip database might suggest: 'Replace C536' for a particular symptom. This is good advice for a specific problem on one model. However, what you really want to understand is why C536 was the cause and how to pinpoint the culprit in general even if you don't have a service manual or schematic and your tech tip database doesn't have an entry for your sick TV or VCR.

While schematics are nice, you won't always have them or be able to justify the purchase for a one-of repair. Therefore, in many cases, some reverse engineering will be necessary. The time will be well spent since even if you don't see another instance of the same model in your entire lifetime, you will have learned something in the process that can be applied to other equipment problems.
As always, when you get stuck, checking out a tech-tips database may quickly identify your problem and solution.In that case, you can greatly simplify your troubleshooting or at least confirm a diagnosis before ordering parts.

Happy repairing!
Today, the West is headed for the abyss. For the ultimate fate of our disposable society is for that society itself to be disposed of. And this will happen sooner, rather than later.

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..............The bitterness of poor quality is remembered long after the sweetness of todays funny gadgets low price has faded from memory........ . . . . . .....
Don't forget the past, the end of the world is upon us! Pretty soon it will all turn to dust!

©2010, 2011, 2012, 2013, 2014 Frank Sharp - You do not have permission to copy photos and words from this blog, and any content may be never used it for auctions or commercial purposes, however feel free to post anything you see here with a courtesy link back, btw a link to the original post here , is mandatory.
All posts are presented here for informative, historical and educative purposes as applicable within fair use. NOTHING HERE IS FOR SALE !

Tuesday 19 March 2019

ACER ASPIRE 4920 - HOW TO BYPASS PASSWORD - BIOS RECOVERY

ACER ASPIRE 4920 - HOW TO BYPASS PASSWORD - BIOS RECOVERY


PASSWORD BYPASS
Operation Procedures of Password Bypassing and BIOS Recovery.
For RD and CSD to debug easily, the system provide one hardware DIP switch for Bypassing Password
Check, and one Hotkey to enable BIOS Recovery.
DIP Switches
DIP => SW1
Default Setting => Disabled (High)
Description => Bypassing Password Check.
Bypassing Password Check (SW1):
If the user has set Password (power-on or set-up password) for security reason, BIOS will check password during POST or when entering the BIOS set-up menu. However, if it is necessary to ignore the password check, the user may enable DIP SW1 to bypass password check.  BIOS Recovery: Boot Block is a special block of BIOS. It is used to boot up the system with minimum BIOS initialization. The user can enable this feature to restore the BIOS to a successful one if previous BIOS flashing process fails.
DIP Switch Location:

RD/CSD can enable or disable this function by switching the DIP. The Dip switch is located as shown in the figure below:
Clear Password
DIP SW1: Bypassing Password Check is disabled by default. Switching into ON then powering on the system will force the BIOS to clear Supervisor and User passwords. The power-on, set-up password, and the HDD password are all cleared.
[Short R525 to clear password.]
Restore BIOS by the Crisis Disk
Enable this function by pressing the combination: Fn+ESC, and pressing the Power Button. To use this function, it is strongly recommended that the AC adapter is connected to the system and plug-in to a wall outlet and the Battery is also in the system. If this function is enabled, the system will force the BIOS to enter a
special BIOS block, called BootBlock. RD/CSD can use this special BIOS code to recover the BIOS to a successful one if previous BIOS flashing process fails. However, before doing this, one Crisis Disk should be prepared in WinXP. Detailed steps are as the followings:
  • Prepare the Crisis Disk in WinXP
  • Insert the Crisis Disk to a USB floppy drive which is attached to the failed machine.
  • While the system is turned off, press and hold Fn+ESC, then press Power Button. The system should be powered on with Crisis Recovery process.
  • BootBlock BIOS starts to restore the failed BIOS code. Short beeps should be heard when flashing.
  • If the flashing process is finished, a long beep should be heard.
  • Power down the system after you hear the long beep.
If the crisis recovery process is finished, the system should be powered on with the successful BIOS. RD/CSD can then update the BIOS to a workable one by regular BIOS flashing process.