Green 755

Green 755

Green 755

Also sold as the Micron Transport VLX plus the NEC Ready Ready 200T Series

The Green 755 laptop was sold by many brands of "white-box" generic laptop OEM's plus it was also sold as the Micron TransPort VLX and even sold as the NEC Ready 220T - 240T series of laptops. I have been informed that the Zenith Z-Star 700 also appears to have been a Green 755. I have not been able to verify that on my own.

No matter if you have a generic Green 755 or one of the custom labeled versions - all are identical under the skin. Plastic case cosmetic details or case colors may vary, but the main electronics are all the same.

LCD's range from commonly found 11.3" dualscan, 11.3" TFT (rare) and on up to 12.1" dualscan and TFT versions. LCD lid plastics is nearly impossible to find in like new condition.

Micron Transport VLX Details & Models

As stated above, other than minor plastic case changes to the VLX case plus Micron's custom satin black painted case, the VLX is the exact same latop as all of the other brands. Micron had the VLX plastic case pieces painted black (vs. standard dark gray) so generic Green 755 plastic case parts will need to be painted to match the VLX's color scheme.

Micron VLX - NBK001235-00 = 11.3" Dual Scan (P133 CPU)

Micron VLX - NBK001350-00 = 11.3" TFT (P150 CPU?)

Micron VLX - NBK001349-00 = 12.1" TFT (P150 CPU?)

Note: The Micron VLX-enhanced is not a Green 755 laptop and has a completely different motherboard. However these laptops do share the Green 755 drive modules See Green 756.

Green 755

The general construction of the Green 755 is closely related to the Green 735 and Green 756 )Micron VLX-Enhanced or Trek), but the G755 shares a few parts with either of these other models.

It does share an AC adapter design with the Green 753. The very hard to find 4 pin adapter that we do have in stock.

All Green 755 motherboards were designed for use with the Intel Socket 5 (often called Socket 7) CPU's. A Pentium 200 MHz (not the 200 MMX) CPU is the fastest CPU for use in these laptops. Intel Petium MMX CPU's can be used, but MMX instructions are not supported. AMD K6 CPU's will NOT operate and no POST screen will occur if one of these CPU's is installed in a Green 755.

The Green 755 has only a single drive bay and unless you have an external drive adapter "L" bracket you will need to swap the floppy module and the CD-ROM module as needed. Do NOT hot swap these modules or damage to the laptop and/or module will occur. You must power down to swap drives.

The hard drive module and the memory can be found by removing four screws located along the front edge of the lower case. Once the four screws are removed the front of the upper case can be lifted up. This palmrest section of the top case comes off to reveal the hard drive carrier module. This module is held in place with a single screw and at first glance, appears to be identical to the Green 735 carrier module , but the Green 735 HDD carrier has a different connector that prevents the closure of the Green 755 palmrest.

There's two memory slots that are located under the hard drive carrier module. The Green 755 uses 72 pin EDO SODIMM's. The maximum memory appears to be 72 MB - 8 MB on the motherboard and two 32 MB modules in the expansion slots.

When the palmrest is removed the keyboard can be raised to reveal a metal heat sink plate for cooling the CPU. Lifting up of this metal plate reveals the CPU and CPU socket. There's also two DIP switches under the metal plate and one is the speed setup switch for the CPU. The second switch is a setup switch for the CPU Vcc voltage. The keyboard cable passes through the cooler plate and the keyboard can be removed by gently lifting the locking portion of the connector mounted on the motherboard.

The AC power adaptor has 19 volt output and the hard to find four pin connector. It can be a hard adaptor to replace, but I still have these AC adaptors in stock.

Batteries

Fedco Electronics (maker of Energy Plus batteries) had an incorrect battery listes for use with the Green 755's and I supplied them with a testbed G755 so they could see if they could modify this battery for use in the Green 755. They have confirmed that the batteries are incorrect as manufactured and need to update their battery list to delete the Green listing for this battery. So DO NOT purchase replacement batteries elsewhere unless that vendor has a good return policy.

The Energy Plus Li Ion battery listed for the Micron VLX does not function in the VLX or Green 755 laptop. The Energy Plus NiMH battery for the VLX is the only correct battery that functions, but is a tight fit in the battery compartment. The Li Ion battery listed for the VLX works in a Trek or Green 735 only!

Plastic Case

The major weaknesses of the Green 755 design seems to be centered around plastic case construction. The LCD lid breaks at the hinges. Most often this is caused by hard to move hinges and/or loose mounting screws in the lid assembly. If you detect any play at the hinges make sure to open the LCD lid assembly and tighten all of the screws. Do so before the plastic mounting studs break. (Remove all power sources before opening the LCD lid assembly) New lids or good condition used lids are very hard to find.

The top main case is also weak design and often breaks. Remove the LCD lid assembly when removing the palmrest or be sure to support the LCD lid from behind before disassembling the laptop. All of the LCD lid weight is leveraged against the top case's front plastic, which is quite weak, and causes the plastic to crack.

Motherboard & Other Boards

The motherboard in the Green 755 has a DC/DC power board that plugs into the left front corner of the area under the keyboard. This is the voltage regulator power supply for most of the voltages needed in the laptop. This allows for a quick and simple repair should one of the internal power regulators be damaged. The CPU Vcc DIP (dual inline package) switch settings are found on this power board and needs to be correctly set for the type of CPU being used. Only one switch in the four switch bank will be "ON" for each voltage.

Power Board CPU Vcc Settings

Pwr Brd	2.5V	2.9V	3.1V	3.3V
SW1-1	---	---	---	---
SW1-2	OFF	ON	OFF	OFF
SW1-3	OFF	OFF	ON	OFF
SW1-4	OFF	OFF	OFF	ON

CPU Speed Settings

Motherboard SW1	SW1-1	SW1-2	SW1-3	SW1-4	SW1-5	SW1-6	SW1-7	SW1-8
75	OFF	ON	OFF	OFF	ON	OFF	ON	OFF
90	ON	OFF	OFF	OFF	OFF	OFF	ON	OFF
100	OFF	OFF	OFF	OFF	OFF	OFF	ON	OFF
120	ON	OFF	OFF	OFF	ON	OFF	ON	OFF
133	OFF	OFF	OFF	OFF	ON	OFF	ON	OFF
150	ON	OFF	OFF	OFF	ON	ON	ON	OFF
150M	ON	OFF	OFF	OFF	ON	ON	ON	OFF
166M	OFF	OFF	OFF	OFF	ON	ON	ON	OFF
200M	OFF	OFF	ON	OFF	OFF	ON	ON	OFF

M = Mobile CPU

The Intel 166MMX, 200 MMX or 233mmx CPU can be installed, but the heat output from the 233MMX is too much for the CPU cooler plate to handle and so overheating will occur if the laptop is used for extended periods of time. Since the G755 BIOS doesn't support the MMX instructions there is little to be gained by using these CPU's.

CPU switch setting above are not for ANY MMX CPU's - you will need to experiment to find the correct setup for your MMX CPU, please don't email asking for this information. Don't forget to change the Vcc voltage to 2.9 volts if you install a MMX CPU.