Replacing my smt Bios

By rprzybylow ·

I have decided the problem with my PC is that the Cmos is bad. I have extracted it from the MOBO using my Brand new SMD Rework station...:-)

My question is; will another sst Cmos work or do I have to have the exact numbers on the chip.

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If the CMOS chip

by IC-IT In reply to Replacing my smt Bios

is from an exact duplicate motherboard (same make, model, revision), there shouldn't be a problem.
You can also Google CMOS (or BIOS) replacement chips to find sellers and purchase a new one.

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Flash ROM or CMOS?

by TheChas In reply to Replacing my smt Bios

While either way, you need the pretty much the exact same chip, what you will need to do depends on if you are replacing the CMOS RAM chip or the Flash BIOS ROM IC.

The Flash ROM holds the actual BIOS code. Without the correct BIOS in the Flash ROM, you will not be able to boot your computer and load the bios into the flash ROM. You will either need a programming station for the Flash ROM, or you must purchase a Flash ROM that has been pre-loaded with the specific BIOS for your motherboard.

Now, if it is the CMOS RAM chip, while it still needs to be the same size and speed, there should be no problem replacing it with a chip made by a different manufacture.

In the case of replacing the CMOS RAM, your motherboard will power up the same way it would if you were to reset the CMOS. You will need to enter BIOS Setup and set or at least verify all of the settings.

Back to your base question:
Flash ROM:
Same manufacture, same series, speed and amount of ROM are required. Minor differences in revision should not be a problem.

Must be same speed and same amount of RAM. While nearly any manufactures part should work, there may be some CMOS RAM chips that will not work properly with the BIOS Flash ROM. It would be best to get the same manufactures part.

I am very curious as to what kind of failure you tracked down to either the CMOS or the Flash memory IC. I would expect many other things to fail long before either of these devices would fail.


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My conclusion

by rprzybylow In reply to Replacing my smt Bios

MOBO gets power, HDD Powers up, Tried 3 PSU's, swapped the Ram, No beeps, No post, Fans spin on and never settle down. I have replaced Battery, and flashed bios with no success. Only thing I can concider is the Bios has failed. I tried 3 graphics cards too.

I forgot to mention, this is my Dad's Computer. I am 32 and need to fix it for him. Cause I can?

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Well in that case you need an Identical BIOS Chip

by OH Smeg Moderator In reply to My conclusion

These are an EPROM and they have different Pin outs for Different Chips.

Then you need one programed with the right BIOS Version and unless you have the ability to program EPROMS you will need to buy one form one of the BIOS Suppliers like Biosman

I've bought numerous BIOS Chips from this company in the past whenever I need to change the BIOS in Servers and never had a problem with any of the Chips that they have sent me over the years. I've found them to be very good.

But having said that I very much doubt that the BIOS IC is the problem I would be looking for Failed IC elsewhere on the M'Board which are not easily/economically replaceable.


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MOBO Regulators

by TheChas In reply to My conclusion

I cannot recall ever having a failed BIOS Flash ROM on a motherboard. BTW, how can you flash the BIOS if the system does not POST?

I would first suspect things like the voltage regulators on the motherboard.

Any number of circuits might not be getting the correct voltage from the on-board regulators.

I would also closely inspect the filter capacitors on the motherboard. I have observed failed filter caps on at least 3 different batches of boards. Any bulges of the top of a filter cap is clear evidence of a failure. The bad thing is that sometimes when the filter cap fails, nearby components fail. Just recently, we had 3 systems fail almost simultaneously. When we had the on-board Gig-E connected, the system would freeze. 2 filter caps near the controller chip had failed.


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Could still be

by IC-IT In reply to My conclusion

either the Motherboard or the CPU. You could check to see which CPU's it can handle. Then get a little thermal paste and switch the CPU out. Or if the known working system can handle that CPU try it in there.

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