How To Check For Bad Ram Slot

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If the system fails to post remove last DIMM installed and set aside, continue from last DIMM slot and install another stick. (repeat with any other failed DIMMs) 6. If multiple sticks fail in the same DIMM slot install a confirmed working DIMM and verify if the slot is bad. (Make note of defective slot using DIMM guide DIMMD1, etc.).

Recently one of our blog readers raised this question that there are some errors when buying a used slot machine. Though his query was related to his IGT Double Diamond model 96435800 reel slot machine which he had bought but here we are catering to some of the most common errors buyers face when they buy a real slot machine specially a refurbished ones. You can try to fix these errors by doing the following actions as given against each error. Also there are many superb videos online that teach you how to fix these errors.

How to check for bad ram slots

EEPROM Device Error

  • I shut the machine down, re-seated the new RAM (and verified that I had, in fact, put the new sticks in). One of the new sticks must be bad, I thought. So I swapped them. So it isn’t the sticks. Must be one of the slots. So I booted up with a stick in only one of the 2 slots.
  • Again, Your memory slot can be the real culprit. So, Just place the RAM module to another slot and see what happens. There are many trusted tools to diagnose this problems. You also can use that. How to Fix RAM Problems: OK. Most of the time, You may need to buy a new RAM module or replace. Anyway, These are the things you can do – At first.
  • CMOS RAM Error This means Bad (or cleared) CMOS RAM data You can Press test button 3 seconds Error code 61-1 should now be displayed. Now close door, turn and release reset key once. Same for game data reset.
  • Test RAM with Windows Memory Diagnostic Tool Your Windows operating system comes with a built-in utility for diagnosing memory issues. It’s called Windows Memory Diagnostics. Open Control Panel (press Windows key and R Run box will appear type ncpa.cpl and hit enter).

EEPROM (electrically erasable programmable read-only memory) is user-modifiable read-only memory (ROM) that can be erased and reprogrammed (written to) repeatedly through the application of higher than normal electrical voltage. Unlike EPROM chips, EEPROMs do not need to be removed from the computer to be modified. However, an EEPROM chip has to be erased and reprogrammed in its entirety, not selectively. It also has a limited life – that is, the number of times it can be reprogrammed is limited to tens or hundreds of thousands of times. In an EEPROM that is frequently reprogrammed while the computer is in use, the life of the EEPROM can be an important design consideration.

A special form of EEPROM is flash memory, which uses normal PC voltages for erasure and reprogramming.

Here is the video how to fix this error

Error on door of slot machine

Many times when the display on the door indicates an error condition, open and close the door to reset the game and clear the error. Open the main door which clears the current game information and a “0” appears in the Coins Played window. Closing the door resets the game and the reels will spin and stop in their last valid position. The error code should clear and the digital display returns to normal game play.

Error Code 12 Battery Voltage

To fix this error turn power off and then turn power on if the battery voltage has dropped below 2.9 V. Also replace ASAP due to possible RAM (Memory) corruption. Open / close door to clear and also Replace 3.6 V Lithium battery on CPU board.

Coin Errors

For coin errors see that comparitor is seated in all four acceptor clips and that acceptor does not have coin(s) jammed or the coin optics below comparitor is not blocked You can ensure toggle power switch is in activated position if installed.

Coin Out Tilt Hopper

Check for and clear any jammed coins in the coin out channel. Also see that the coins are not jammed behind hopper knife or see that the coin out optic sensor is not blocked by dust. If so you can replace hopper coin out optic.

Error in Extra Coin Out Hopper

To fix this see that the hopper motor brake functions properly. Check the coin wiper/ knife for jams and if so adjust them if necessary.

Hopper Empty Error

This is the most common error that new slot machine owners will have because the cash out button was pushed and the number of coins in the hopper is less than the total credits to be paid out. You can open the main door and check the hopper for coin level (your hopper will not dispense all of the coins), refill and close the main door. You may have to do this several times for all of the credits to be paid out.

Reel Tilt Errors

You will find that there are reel tilt errors and for this see that whether the designated reel is misaligned or malfunctioning. Also check if the reel is not unplugged. You can switch connectors from one reel to another, determine if error follows change of connectors. Try replacing reel assembly or optics if error stays with bad reel. Also clear Ram and see if it works again.

Error Codes and Fixes

During the process of clearing error codes, you may encounter multiple 6x series errors. Here are few common ones and their fixes

CMOS RAM Error

This means Bad (or cleared) CMOS RAM data You can Press test button 3 seconds Error code 61-1 should now be displayed. Now close door, turn and release reset key once. Same for game data reset.

Bad Game EPROM or Data EPROM Error

Check circuit board and replace Game EPROM. For Data EPROM error check circuit board and replace Reel EPROM

How To Check For Bad Ram Slots

Bad EPROM Device or Bad EPROM Data or Game Type Mismatch

Press self test switch for 3 seconds If error will not clear replace EPROM Also if the processor could not read or write to the named chip Press test button for 3 seconds Error code clears from display.

Most of the errors can be resolved with little help but many need technical knowledge. Remember that if you are on a warranty or not the place or online site where you purchased a used slot machine is there to assist you with trouble shooting and repairs. They can guide you over the phone or send some mechanical and technical person to do so.

Troubleshooting Memory Errors

MemTest86 detected errors in my memory. Is there something wrong with my RAM?

Please be aware that not all errors reported by MemTest86 are due to bad memory. The test implicitly tests the CPU, L1 and L2 caches as well as the motherboard. It is impossible for the test to determine what causes the failure to occur. However, most failures will be due to a problem with memory module. When it is not, the only option is to replace parts until the failure is corrected.

Sometimes memory errors show up due to component incompatibility. A memory module may work fine in one system and not in another. This is not uncommon and is a source of confusion. In these situations the components are not necessarily bad but have marginal conditions that when combined with other components will cause errors.

Often the memory works in a different system or the vendor insists that it is good. In these cases the memory is not necessarily bad but is not able to operate reliably at full speed. Sometimes more conservative memory timings on the motherboard will correct these errors. In other cases the only option is to replace the memory with better quality, higher speed memory. Don't buy cheap memory and expect it to work reliably. On occasion 'block move' test errors will occur even with name brand memory and a quality motherboard. These errors are legitimate and should be corrected.

All valid memory errors should be corrected. It is possible that a particular error will never show up in normal operation. However, operating with marginal memory is risky and can result in data loss and even disk corruption. Even if there is no overt indication of problems you cannot assume that your system is unaffected. Sometimes intermittent errors can cause problems that do not show up for a long time. You can be sure that Murphy will get you if you know about a memory error and ignore it.

We are often asked about the reliability of errors reported by MemTest86. In the vast majority of cases errors reported by the test are valid. There are some systems that cause MemTest86 to be confused about the size of memory and it will try to test non-existent memory. This will cause a large number of consecutive addresses to be reported as bad and generally there will be many bits in error. If you have a relatively small number of failing addresses and only one or two bits in error you can be certain that the errors are valid. Also intermittent errors are without exception valid. Frequently memory vendors question if MemTest86 supports their particular memory type or a chipset. MemTest86 is designed to work with all memory types and all chipsets.

MemTest86 cannot diagnose many types of PC failures. For example a faulty CPU that causes Windows to crash will most likely just cause MemTest86 to crash in the same way.

Why am I only getting errors during Test 13 Hammer Test?

How To Check For Bad Ram Slot Speed

The Hammer Test is designed to detect RAM modules that are susceptible to disturbance errors caused by charge leakage. This phenomenon is characterized in the research paper Flipping Bits in Memory Without Accessing Them: An Experimental Study of DRAM Disturbance Errors by Yoongu Kim et al. According to the research, a significant number of RAM modules manufactured 2010 or newer are affected by this defect. In simple terms, susceptible RAM modules can be subjected to disturbance errors when repeatedly accessing addresses in the same memory bank but different rows in a short period of time. Errors occur when the repeated access causes charge loss in a memory cell, before the cell contents can be refreshed at the next DRAM refresh interval.

Starting from MemTest86 v6.2, the user may see a warning indicating that the RAM may be vulnerable to high frequency row hammer bit flips. This warning appears when errors are detected during the first pass (maximum hammer rate) but no errors are detected during the second pass (lower hammer rate). See MemTest86 Test Algorithms for a description of the two passes that are performed during the Hammer Test (Test 13). When performing the second pass, address pairs are hammered only at the rate deemed as the maximum allowable by memory vendors (200K accesses per 64ms). Once this rate is exceeded, the integrity of memory contents may no longer be guaranteed. If errors are detected in both passes, errors are reported as normal.

The errors detected during Test 13, albeit exposed only in extreme memory access cases, are most certainly real errors. During typical home PC usage (eg. web browsing, word processing, etc.), it is less likely that the memory usage pattern will fall into the extreme case that make it vulnerable to disturbance errors. It may be of greater concern if you were running highly sensitive equipment such as medical equipment, aircraft control systems, or bank database servers. It is impossible to predict with any accuracy if these errors will occur in real life applications. One would need to do a major scientific study of 1000 of computers and their usage patterns, then do a forensic analysis of each application to study how it makes use of the RAM while it executes. To date, we have only seen 1-bit errors as a result of running the Hammer Test.

There are several actions that can be taken when you discover that your RAM modules are vulnerable to disturbance errors:

  • Do nothing
  • Replace the RAM modules
  • Use RAM modules with error-checking capabilities (eg. ECC)

Depending on your willingness to live with the possibility of these errors manifesting itself as real problems, you may choose to do nothing and accept the risk. For home use you may be willing to live with the errors. In our experience, we have several machines that have been stable for home/office use despite experiencing errors in the Hammer Test.

You may also choose to replace the RAM with modules that have been known to pass the Hammer Test. Choose RAM modules of different brand/model as it is likely that the RAM modules with the same model would still fail the Hammer test.

For sensitive equipment requiring high availability/reliability, you would replace the RAM without question and would probably switch to RAM with error correction such as ECC RAM. Even a 1-bit error can result in catastrophic consequences for say, a bank account balance. Note that not all motherboards support ECC memory, so consult the motherboard specifications before purchasing ECC RAM.

Detection and mitigation of row hammer errors

The ability of MemTest86 to detect and report on row hammer errors depends on several factors and what mitigations are in place. To generate errors adjacent memory rows must be repeatedly accessed. But hardware features such as multiple channels, interleaving, scrambling, Channel Hashing, NUMA & XOR schemes make it nearly impossible (for an arbitrary CPU & RAM stick) to know which memory addresses correspond to which rows in the RAM. Various mitigations might also be in place. Different BIOS firmware might set the refresh interval to different values (tREFI). The shorter the interval the more resistant the RAM will be to errors. But shorter intervals result in higher power consumption and increased processing overhead. Some CPUs also support pseudo target row refresh (pTRR) that can be used in combination with pTRR-compliant RAM. This field allows the RAM stick to indicate the MAC (Maximum Active Count) level which is the RAM can support. A typical value might be 200,000 row activations. Some CPUs also support the Joint Electron Design Engineering Council (JEDEC) Targeted Row Refresh (TRR) algorithm. The TRR is an improved version of the previously implemented pTRR algorithm and does not inflict any performance drop or additional power usage. As a result the row hammer test implemented in MemTest86 maybe not be the worst case possible and vulnerabilities in the underlying RAM might be undetectable due to the mitigations in place in the BIOS and CPU.

Why do I get errors only when testing RAM modules together, and not when individually tested?

Most memory systems nowadays operate in multiple channel mode in order to increase the transfer rate between the RAM modules and the memory controller. It is recommended that modules with identical specifications (ie. 'matching modules') when running in multi-channel mode. Some motherboards also have compatibility issues with certain brand/models of RAM when running in multi-channel mode.

When you see errors while running MemTest86 with multiple RAM modules installed, but not when they are tested individually, it is likely that the multi-channel configuration is the culprit. This could be due to mismatched RAM specifications, or simply using brands/models of RAM that is incompatible with the motherboard. Most motherboard vendors release a list of known compatible RAM models that have been tested to work with your motherboard. Replace the modules with a matching set of known good ones and see if you get better results.

MemTest86 reported the memory address of the failure. What does this mean?

When MemTest86 detects errors during the memory tests, the memory address, actual and expected data are reported to the user. The memory address is the location in system memory where the data contained does not match what was expected. This is the address that is specified by the CPU to the memory controller when requesting data from DRAM. The memory controller then decodes this memory address to identify the specific channel, DIMM, rank, DRAM chip, bank, row and column in DRAM using a chipset-specific address decoding scheme.

The address decoding scheme is the process used by the memory controller to generate the appropriate address signals to the DRAM chip. Depending on the memory controller, this process can get fairly complex as it is not simply a a direct mapping of the system address bits to the DRAM address bits. In order to increase the memory performance, strategies such as channel interleaving (for Dual, Tri and Quad channel setups), rank/bank/row interleaving, and address swizzling are used to increase the concurrency of memory accesses. For some chipsets such as AMD, the address decoding scheme can be configured/determined via PCI registers as described in the chipset specifications. For other chipsets (eg. Intel), however, the address decoding scheme is proprietary and not made available to the public. This makes identifying the DRAM address and correspondingly, the failing module, much more difficult. For that reason, MemTest86 does not have the capability to report the DRAM addresses and thus, the failing DIMM, of memory errors.

How does MemTest86 report ECC errors?

If ECC detection and correction is enabled on the system, MemTest86 is able to report any detected ECC errors to the user. Depending on the chipset that is used, the reported address of the ECC error may either be the system memory address (eg. 0x93801200) or the DRAM rank/bank/row/column address (eg. 0x3E0, 0x5F6D, 0x2, 0x2). This is entirely dependant on the chipset that is used and how the hardware reports the ECC error details to the system; Ie. MemTest86 does not have the capability to interchange between displaying the system address or the DRAM address.

If I know the address decoding scheme, can I configure MemTest86 to report the failing module?

For systems where the address decoding scheme is known, MemTest86 provides several configuration file parameters to aid users in determining the faulty module that corresponds to the memory address:

For each of these 3 parameters, a list of bit positions can be used to specify which address bits of a memory address to exclusive-or (XOR) in order to determine the corresponding [memory channel|slot|chip select (CS)] (0 or 1) of the failing module. This is only useful if you know that the memory controller maps a particular address to a [memory channel|slot|chip select (CS)] using this XOR-based decoding scheme. If these parameters are specified and MemTest86 detects a memory error, the [memory channel|slot|chip select (CS)] will be calculated and displayed along with the faulting address.

How do I know which RAM module is failing?

Once a memory error has been detected, determining the failing SIMM/DIMM module is not a clear cut procedure. Different CPUs map memory addresses to physical memory sticks in different ways. Features like dual channel RAM (with interleaving), channel hashing and NUMA make the mapping of addresses to modules, banks & rows very difficult. With the large number of CPUs and motherboard vendors and possible combinations of memory slots it would be difficult if not impossible to assemble complete information about how a particular error would map to a failing memory module. However, there are steps that may be taken to determine the failing module. Here are some techniques that you may wish to use:

  1. Removing modules

    This is simplest method for isolating a failing modules, but may only be employed when one or more modules can be removed from the system. By selectively removing modules from the system and then running the test you will be able to find the bad modules. Be sure to note exactly which modules are in the system when the test passes and when the test fails.

  2. Rotating modules

    When none of the modules can be removed then you may wish to rotate modules to find the failing one. This technique can only be used if there are three or more modules in the system. Change the location of two modules at a time. For example put the module from slot 1 into slot 2 and put the module from slot 2 in slot 1. Run the test and if either the failing bit or address changes then you know that the failing module is one of the ones just moved. By using several combinations of module movement you should be able to determine which module is failing.

  3. Replacing modules

    If you are unable to use either of the previous techniques then you are left to selective replacement of modules to find the failure.

How do I fix the memory errors?

Depending on what is causing the memory errors, you can try the following options:

  • Replace the RAM modules (most common solution)
  • Set default or conservative RAM timings
  • Increase the RAM voltage levels
  • Decrease the CPU voltage levels
  • Apply BIOS update to fix incompatibility issues
  • Flag the address ranges as 'bad'

Once you have determined with certainty which RAM module(s) have failed, replacing them with a new set of RAM modules usually fixes the errors. When choosing which modules to use as a replacement, consider using one that is listed as compatible by the motherboard vendor as it would have been verified by the vendor itself.

How To Check Faulty Ram Slot

Sometimes, memory errors only manifest themselves when RAM timings are set too aggressively in the BIOS (eg. overclocking). For certain modules that support higher performance XMP timings, consider using standard, non-XMP timings to see if you get better results. Consult your motherboard manual on how to set or reset your RAM timings to default settings.

How To Check For Bad Ram Stick

For certain configurations (especially when using aggressive RAM timings), higher voltage may be required in order to operate the RAM in stable conditions. If you are using non-standard RAM timings, slightly increasing the voltage (eg. from 1.5V to 1.55V) may increase the stability. Increase the voltage at your own risk as excessive voltage may damage the components of your system

A higher CPU voltage may cause overheating, resulting in memory errors that lead to system hangs/crashes. Check with the motherboard vendor for instructions on configuring CPU voltage levels.

In certain cases, RAM incompability issues can be fixed with a BIOS update. Check the motherboard vendor for updated BIOS with RAM compaibiliy fixes.

Several operating systems allow the user to pass in a list of 'bad' memory ranges to prevent the operating system to use or allocate memory in that range. See Blacklisting RAM Pages for more details.

Why are ECC errors not being reported on my ASRock/AMD Ryzen system?

There is a possibility that a BIOS setting, 'Platform First Error Handling' (PFEH), is preventing ECC errors from being reported to MemTest86. If this setting is enabled, set to disabled and try running MemTest86 again.