No Nvram found - Lexmark T 640 - printer - B/W - laser

CD370 errors occurs when• Multiple errors are detected by the
abnormal check of each NVRAM data.
You need to reset the printer's NVRAM . First find out how.

It isn't mentioned in the KBizhub350 User Manual, as required by government. Any fraudulent activity is also kept on the nvram. (copy bank notes).

NVRAM problems better calll KM tech because this kind of error codes need specialez tech and procedure like NVRAM data recovery etc

NVRAM should be your BIOS, if that's not found you've got something wrong with your motherboard. I don't think it's a dead CMOS battery but you could try changing it, dead CMOS batteries usually say bad checksum.

edit: try removing any hardware you don't need for the computer to boot then if it works, add them back one by one __________________

NVRAM initialization
CAUTION NVRAM initialization will erase all network settings. Before performing NVRAM
initialization, print a Network Configuration page, which contains network-setting information.
NVRAM initialization performs the following actions:
? Resets all customer-accessible menu settings via control panel and software back to the factory
default settings
? Resets the language to the value set at the factory
? Resets the default media size to cold reset media size
? Resets the symbol set to PC-8
NOTE The following steps reset the same NVRAM locations that are reset using the
Restore Defaults option in the control panel Service menu. The following process should be
used if the MFP does not come to a Ready state and an NVRAM initialization is desired.
Use the following procedure to perform an NVRAM initialization.
1. Turn off the printer.
2. Press and hold the Right arrow and Cancel buttons simultaneously.
3. Turn on the printer.
4. When you see the message Permanent storage init, release the Right arrow and Cancel buttons.
When the NVRAM init is complete, the printer returns to the Ready state.

Self-diagnosis error: Standard NVRAM The controller cannot recognize the standard NVRAM installed or detects that the NVRAM is defective • Loose connection • Defective standard NVRAM • Defective controller 1. Turn the main switch off and on. 2. Check the standard NVRAM is firmly inserted into the socket. 3. Replace the NVRAM. 4. Replace the controller.

The way that I have found to fix this problem is to replace the logic board but when you do that, this is where the NVRAM mismatch comes in. Once you change the logic you also have to change the display op panel. That is what is giving you this error. You must change logic and op panel at same time and it will not give that error.

This is from Lexmark's support page....sounds like a hardware issue....

NVRAM Failure 953: NVRAM Chip Failure
954: NVRAM CRC Failure
Optra T 640/642/644
953 - Replace the operator panel board or upper front cover.
954 - Replace the interconnect card.

According to http://www.laserquipt.com/support/idx/42/615/article/-Reset-the-Printer-to-the-Factory-Defaults-NVRAM-Reset-.html (and it worked for me):



NOTE: Resetting NVRAM returns stored parameters in the image processor board NVRAMto their factory default values. The print count and the Adobe firmwareserial number are not affected by this reset. You can reset the PostScript NVRAM using the Service Tools menu or the Service Diagnostics menu.
To reset the printers NVRAM using the Service Tools menu:

NOTE: Print a Configuration Page before resetting NVRAM.
Pressand hold the [Up] arrow button on the Control Panel, and then press the[OK] button. This will automatically display the Service Tools menu onthe Display Screen.

1. Press the [OK] button.
2. Press the [Up] or [Down] arrow button to select [Reset NVRAM], and then press the [OK] button.

To reset the printers NVRAM using the Control Panel:

1. Pressthe [Up] or [Down] arrow button on the Control Panel to select[Troubleshooting] on the Display Screen, and then press the [OK]button.
2. Press the [Up] or [Down] arrow button to select [Service Tools], and then press the [OK] button.
3. Press the [Up] or [Down] arrow button to select [Reset NVRAM], and then press the [OK] button.
4. Press the [Up] or [Down] arrow button to select [Exit], and then press the [OK] button to return to the Main screen.

In answer to the clarification request, I suspect they have lost the admin password. Does that help you answer the question?

You have to install a brand new front display, the display board has a backup of the nvram, on boot the system board check the nvram and if it don't match it will return an NVram mismatch error

NVRAM init NVRAM init returns all stored parameters in NVRAM to factory default values or to a default ROM value, depending on the variable, and performs a system reset. Performing NVRAM init can cause the product to violate local telephone regulations. Reset the language and country/region after performing NVRAM init. ENWW Service-mode functions 265 NVRAM init resets the following settings and information: ● All menu settings are reset to factory default values, including fax header and company name. ● Factory settings such as formatter number, page counts, and factory paper settings are reset. ● All faxes in memory are erased. ● All speed-dials, group-dials, and phone book entries are erased. ● All localization settings, including language and country/region, are reset. To perform NVRAM init 1. Turn off the product. 2. Press and hold down the * and MENU/ENTER buttons. 3. Continue to hold down the buttons while you turn on the product. Hold the buttons through the entire power-on sequence. 4. When Permanent Storage Init. appears on the control-panel display, release the buttons. 5. When the message Language appears on the control-panel display, set the correct language and country/region. 6. Allow the product to return to Ready before using the product.