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SIMCHECK II is an older model that is no longer in production. It has been superseded by the RAMCHECK LXand RAMCHECK.


Q. What is the SIMCHECK II PLUS? What is the difference between this and the SIMCHECK II se PLUS?
A. The SIMCHECK II PLUS is a package that includes both the base tester SIMCHECK II and the Sync DIMMCHECK 168. The SIMCHECK II se PLUS includes the base tester SIMCHECK II se and the Sync DIMMCHECK 168. As both of these packages include the Sync DIMMCHECK 168, the main differences involve the two base testers. Please visit the SIMCHECK II se features page for a list of these differences.

Q. Is the SIMCHECK II Y2K compliant?
A. Yes. Please refer to our page on Y2K compliance for a detailed explanation.

A. Not at this time. The testing technology is currently in development.

Q. What is SIMCHECK IIse and how does it differ from the SIMCHECK II? Can a SIMCHECK II se be upgraded to SIMCHECK II?
A. SIMCHECK II se is a lower cost version of the popular SIMCHECK II. It is equipped with the same fundamental electronics and abilities as the SIMCHECK II and uses the same Internet upgradeable firmware of the SIMCHECK II. To reduce its cost, we have eliminated some capabilities as shown in the SIMCHECK II se page. However, the SIMCHECK II se can be readily upgraded to the SIMCHECK II level at any time.

Q. What do the values from the Relative Refresh and Relative Spikes tests mean?
A. These are relative or comparative values given during our data retention tests. The Relative Refresh provides a value for the ability of the memory module to retain data between refresh cycles, while the Spikes figure gives a value on how well a module can sustain voltage spikes before data loss occurs. See Section 5.3.3 in your SIMCHECK II Manual for further information.

Q. After just receiving my SIMCHECK II PLUS, why am I getting constant memory errors when testing my 30-pin or 72-pin modules, and why does the tester prompt for testing only Sync modules?
A. The SIMCHECK II PLUS is comprised of two pieces. The base tester SIMCHECK II and the additional test adapter Sync DIMMCHECK 168. In packaging, the Sync DIMMCHECK 168 is connected to SIMCHECK II, and when left in this fashion, SIMCHECK II will only work with 168-pin memory (the display will flash "Sync DIMMCHECK 168").

To test 30-pin or 72-pin modules, you will need to remove the Sync DIMMCHECK 168 adapter from the base unit. Removal is performed by TURNING OFF SIMCHECK II and working the adapter upwards while gripping it on its left and right side. When returning to 168-pin testing, TURN OFF SIMCHECK II and reconnect the Sync DIMMCHECK 168.

Q. Can the adapters from SIMCHECK PLUS work on SIMCHECK II?
A. Adapters used with the 40-BIT PORT can be used directly on SIMCHECK II, while others that need the SIMCHECK SIP socket, will require the SIP Adapter for use on SIMCHECK II. Some adapters, such as the HP WS adapter, the x39 IBM adapter, the 3.3V 72P adapter, and the Single -CAS Adapter are not needed with SIMCHECK II as these modules are already supported directly by SIMCHECK II.

Q. What are parity emulation chips? What does the "p" mean on the display 1Mx8p or 2Mx32p?
A. Parity emulation chips are logic devices that provide parity information by being tied directly to your module's data lines, and thusly, bypassing the true parity function. It is important to note that these devices are NOT memory chips, therefore modules detected as having these chips will be identified with the "p" suffix.

Q. Can 72-p or 30-p modules be tested with the Sync DIMMCHECK 168 attached?
A. The Sync DIMMCHECK 168 is a test adapter that focuses SIMCHECK's program to respond only to 168-pin modules inserted in its 168-pin socket. Attempting to test a 72-pin or a 30-pin SIMM while the Sync DIMMCHECK 168 Adapter is connected will result in errors, therefore when testing SIMMs, please REMOVE the Sync DIMMCHECK 168 as it is not integrated into the tester.


Q. Can SIMCHECK II support PC-133 modules?
A. Yes. You will need to download the latest firmware revision and also to review Application Note INN-8558-APN18 that discusses PC-133 determination.

Q. What is SDRAM Technology? Can SIMCHECK II support SDRAM modules including the PC-100 or PC-66?
A. Synchronous DRAM technology provides a revolutionary change in the way DRAM interfaces to a computer. It synchronizes all the read/write transfers to a system clock, thus providing significantly faster transfer rate for contiguous (same Row Address) group of data. A Synchronous DRAM can burst up to a full columns length of continuous data at the device clock rate (currently 100Mhz and higher rates). Both SIMCHECK II and SIMCHECK II se support our new Sync DIMMCHECK 168. This adapter readily supports PC-100 and PC-66 SDRAM memory. You may review Application Note INN-8558-APN14 for an explanation on how SIMCHECK determines PC-100 compliance.

Q. Can I use the SIMCHECK II to program the SPD codes of my SDRAM memory?
A. Yes. The PC Interface software allows you to edit, save, and send SPD data to SIMCHECK II, this data can then be used to program your modules. If you do not need to edit the SPD data, you may also elect to simply read the SPD information from a master module into SIMCHECK II's buffer and then use this data to program others, without using the PC Interface software. Please visit our page on SPD Management and our page on SIMCHECK's Production Mode for further information. You may also consult your manual for further details.

Q. Why can I program the SPD on some modules and not on others?
A. The SPD chips employ a Write Protect Feature which may be active on your module. Typical SPD chips use pin 7 for this Write Protect line. This signal should be shorted to GND in order for the programming process to work. If this signal has been set to Vcc or left open, the chip will not be programmable.

Q. When using the SPD Hex Editor, why doesn't the information change when it is sent to the tester?
A. After a change has been made in the Hex Editor, it is necessary to press <ENTER> afterwards, so the program will receive the changed value. Sending the SPD to SIMCHECK without pressing <ENTER> after the change will send the former information. Further information is available from the on-line SPD Management section and your manual.

Q. The SIMCHECK II shows the speed, Tac access time, and Page Burst. Which is the most accurate parameter for determining PC-100 compliance?
A. There are various parameters that are needed to qualify a module for PC-100 compliance. Currently all of these figures are taken into consideration before SIMCHECK declares the module to be PC-100. You may review Application Note INN-8558-APN14 for an explanation on how SIMCHECK determines PC-100 compliance. Future firmware revisions may add some additional parameters to this determination.

Q. The SPD on the module tested says PC-66, but the test log shows that it is PC-100 Range, will the module work as a PC-100?
A. All of the parameters measured indicate the module to run at a PC-100 level, and it may very well operate as PC-100, however, please remember that modules react differently under different loads. Some modules when used in a complete bank will slow down to the PC-66 level. Please review Application Notes INN-8558-APN13 and INN-8558-APN14 to review what the individual measurements mean.

Q. The SPD on the module says PC-100, but the test log reports it to be PC-66, is the module PC-100?
A. Due to the possibility of loading, some modules may exhibit a slow down in speed. We recommend checking the Tac access times for further reference on PC-100 range. Also, refer to Aplication Notes INN-8558-APN13 and INN-8558-APN14 to review what the individual measurements mean.

Q. What Tac range is appropriate for PC-100 devices?
A. Please refer to Application Note INN-8558-APN13 for an explanation of these limits.

Q. During the Extensive Test, the SDRAM module under test now runs at 83MHz. Does this mean that it is not PC-100?
A. The only test that determines PC-100 compliance is the BASIC Test, so we ask that you check the results after BASIC Test. The frequencies used in the Extensive Test are for other tests altogether. Please refer to Application note INN-8558-APN14 for further information on PC-100 determination.

Q. When programming the SPD, which locations should not be changed.
A. We recommend that the SPD information be changed by the manufacturer only. Please refer to Application Note INN-8558-APN12 for an explanation of the SPD data.

Q. Why do some SDRAM modules test faster than others even though they are the same size, and why does the red LED flash on some modules and not on others?
A. Some SDRAM modules employ a FULL PAGE BURST feature which enables them to test faster. The Page Burst LED (red) will flash vigorously if the module has this feature. Please note that a full page burst is not a requirement for PC100 compliance.

Q. The red LED is still on after the Basic Test. Is it safe to remove the module from the socket?
A. It is safe to remove memory modules when the tester is in STANDBY MODE only. Some modules may exhibit a small current leakage that cause the red LED to remain lit after the test has completed, this is caused by a minute voltage that is present when the tester is in Standby Mode, however, you may safely remove the module when no test is occurring. We do, however, strongly recommend that the module under test remain in the socket while a test is in progress; you should NEVER remove it while it is testing!


Q. How long does it take SIMCHECK II to test a module?
A. It depends on the size and structure of the module, and which tests are performed.
Our proprietary test program is divided into four main tests: BASIC test, EXTENSIVE test, AUTO-LOOP test, and SINGLE BIT test. The BASIC Test is the first test performed by SIMCHECK and it is optimized to be performed at the least amount of time.

Sample BASIC Test Times with existing firmware
4Mx32 3.5 sec.
16Mx36 19.2 sec.
4Mx72 PC-100(with optional Sync DIMMCHECK 168) 5.4 sec.
8Mx72 PC-100(ditto) 9.0 sec.
16x72 PC-100 (ditto) 18.4 sec.
32x72 PC-100 (ditto) 28.5 sec.

BASIC test is sufficient for most of your regular screening and verification tests, since each memory cells is tested several times. BASIC test also provides complete structure and speed information and it manages to complete all the device wiring checks. However, BASIC test may not detect intermittent and/or pattern sensitivity problems due to its short execution time.

EXTENSIVE test may take several minutes as it performs quite a few test phases. You can easily customized SIMCHECK test program to skip any EXTENSIVE test phase in accordance with your preference. The manual includes details on what is accomplished at each test phase so that you can decide which test phases may be skipped in your customized test. Of course, skipping a test will shorten the overall test time.

AUTO-LOOP is our burn-in test, and therefore will run until you abort it. The SINGLE BIT test should be used by technicians for module repair and to extract more advanced information about the module structure.


Q. Why should I upgrade to the new SIMCHECK II Communications program?
A. All future enhancement for the SIMCHECK II line connection to the PC will be made to the new SIMCHECK II Communications program. This program works on the WIN95/98/NT platform. We still include the older Downloader and Realtime Interface program on our web site for customers using WIN3.1/3.11, however we are no longer developing new features with these programs.

Q. What is the Automated SIMCHECK Firmware Upgrade feature of the new SIMCHECK II Communications program?
A. If your computer has a dial-up or direct connection to the Internet, use the Automated SIMCHECK Firmware Upgrade feature to start an automated process that will upgrade your SIMCHECK with the latest firmware version. The process will first download the current SC2F.zip file from our FTP server, will unzip the file and send it to SIMCHECK.

Q. Should the serial port on SIMCHECK II remain permanently connected to a PC?
A. NO. SIMCHECK II is made to be a portable device. The serial port is present to provide FLASH EPROM upgrades and to provide an interface for the Communications program, however, if you intend to leave your tester next to your computer, you may feel free to leave the serial port connected.


Q. How often should the FLASH BIOS on SIMCHECK II be updated?
A. We recommend updating your BIOS about every two months, and whenever you purchase new option. We typically post a new version every month.

Q. What are the benefits of the new program versions?
A. Version changes may include support for new modules that may have not been supported previously or support for adapters that have recently been released. Please refer to the SIMCHECK II Development Log for a detailed explanation of each version.

Q. After downloading the SC2F.zip file from the Downloads page of your web site, how do I send it to SIMCHECK II?
A. If you use WIN95/98/NT, you can install the new SIMCHECK II Communications program and use the Automated Firmware Upgrade described above. However, if you use our older WIN3.1/3.11 programs, or you do not have an internet connection in your computer, you will need to download the SC2F.zip file from our web site. Use your favourable unzip utility to unzip SC2F.zip into the SC2F.bin firmware file. Updating the BIOS is performed by running the downloader program that is enclosed in the SIMCHECK II disk. From this program, open the file SC2F.bin that was downloaded, and select TO SIMCHECK from the SIMCHECK menu (Making sure that the SIMCHECK II unit is in Standby Mode and already connected to an available serial port). When the updating is complete, press ESC to reset the SIMCHECK II unit with its new program. For additional information, please consult your manual.

Q. When upgrading my SIMCHECK II firmware, why do I sometimes run into difficulty while I have the Sync DIMMCHECK 168 installed?
A. The firmware is best upgraded while the SIMCHECK II is without adapters. Simply disconnect any adapter and try upgrading your tester again. If problems persist, please contact our Tech Support Dept.


Q. How can I calibrate my SIMCHECK II?
A. Calibration for SIMCHECK II is not a requirement, but a Calibration & Hardware upgrade is recommended every 12-18 months. This will ensure that your test system is current to factory specifications and has the latest updates and modifications that are necessary to run at its most optimum level.


Q. Can SIMCHECK II support EDO modules?
A. Yes. SIMCHECK II automatically supports Extended Data Out (EDO), Fast Page Mode (FPM), and the old Nibble and Static mode devices.

Q. What is the secondary speed that SIMCHECK II displays?
A. This is the cycle time, the amount of time from one memory access to the next.


Q. Why is the PC COMMUNICATION Software not transmitting the firmware to my SIMCHECK II?
A. It may be necessary to change the COM port setting for SIMCHECK's PC Software. Please refer to the PC Communication Software page to acquire further information on selecting a COM port.

Q. Why are some known good modules failing on SIMCHECK II?
A. It's possible that your SIMCHECK II may need to have its program updated. We recommend updating its program in these instances before calling for tech support. Check our Program Download Sitefor the latest program revision. Please also refer to Application Note INN-8558-APN5 for further reasons on why this may happen.

Q. Why is the latest adapter I just received, not working with my SIMCHECK II?
A. With the rapid development of SIMCHECK II program and new adapters, your SIMCHECK II may still have an older version of the program which does not support the new adapter. Verify that the program version (seen on power up) supports the adapter you are trying to use by reviewing our SIMCHECK II Development Log. ALWAYS MAKE SURE TO UPGRADE YOUR SIMCHECK II VIA THE INTERNET. Check our Program Download Site for the latest program revision.

If the program version is correct, there may be a bad contact between the adapter and the SIMCHECK II expansion slot. A simple tech spray solution applied to the adapter's connector pins will usually eliminate problems that are due to a bad contact or connection.

Q. After various test parameters have been set, I can no longer use the SIMCHECK II without encountering test failures. How can this be corrected?
A. SIMCHECK II uses a nonvolatile EEPROM which stores the setup changes, therefore, when turning it off then on, the previous setup is restored. If this causes problems with modules that the setup was not intended for, simply enter the code sequence F2-F5 from standby mode. This will clear any changes done to the program.


Q. Can the SIMCHECK PLUS power supply be used with SIMCHECK II?
A. NO. The polarity of the SIMCHECK II power source is reversed compared to the SIMCHECK PLUS, therefore only use the power supply that your SIMCHECK II is packaged with. A special diode protects SIMCHECK II if a wrong power supply is used.


Q. How complicated is it to use SIMCHECK II?
A. While SIMCHECK II can produce hundreds of different screens full of information (as you may have seen on this web site) and advanced setup options, we have the reputation of producing the most user friendly machine in our industry. Most users, who care to know only if the device under test is good or bad, can perform the test with pressing only one button (F1). SIMCHECK II automatically detects the type of the tested device and selects the optimal test settings. All test results are clearly displayed (or printed with your PC).

Q. What is the difference between 2K and 4K refresh and can SIMCHECK II support these refresh varieties?
A. The DRAM memory array is arranged along a matrix of Rows and Columns. Each memory cell is accessed by multiplexing first the Row address and then the Column address. The row is the main access, and all the cells in a row are refreshed when the row is accessed. When the number of rows is equal to the number of columns, we say that the DRAM is symmetric, when the rows number is different than the columns number, we say that the DRAM is asymmetric. Asymmetric DRAM has the advantage of reduced power consumption, as less refresh is required. A symmetric 4M device with 11 address lines for both rows and columns has 2K refresh. An asymmetric 4M device with 12 rows and only 10 columns is called 4K refresh. SIMCHECK II automatically detects the refresh type (1K, 2K, 4K and the new 8K). Since historically symmetric devices were first used, SIMCHECK II regards symmetric devices as default, and puts a structure note message when an asymmetric device is encountered.

Q. Can SIMCHECK II test parity, ECC, or parity emulation modules?
A. Yes. SIMCHECK II automatically detects parity and ECC bits, and informs the user if parity emulation chips are used.

Q. What are SIMCHECK II advantages over the competition?
A. SIMCHECK II is our most advance memory tester. The success of our SIMCHECK PLUS, the original portable SIMM tester, enticed several new companies to try to imitate the features of our original design. We do not believe in bad mouthing the competition. Therefore, we would like to show you the advantages of SIMCHECK II by simply comparing it to our older, standard setting SIMCHECK PLUS. Such comparison will clearly highlight SIMCHECK II unique features, so that you can easily do your own comparison between SIMCHECK II and the competition. Please click here to review our comparison.

If you have additional questions, please feel free to EMAIL us at support@innoventions.com. Please remember to include your phone and fax numbers.

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