Motherboard IC U31 burnt again

[jay vyas]

i have a epilog mahcine here in india and my three motherboard have been burnt specially each time i have noticed U31 ic has burnt what is the exact
reason for this ic to burn again and again is it true that due to
humidity this IC burns or bursts or if there is any other particular reason
please let me know

[Rodne Gold]

Is it adequately heat sinked? Is your power to the machine stable? Is there perhaps an intermittent short?

[Dan Hintz]

Can you tell us what that IC is? If you have a schematic I could probably tell you in 30 seconds what the most likely problem is...

[jay vyas]

@rodne

the temperature of the room is around 19-20 degrees celcius when ac is on and the humidity is around 75% when the ac compressor is on and when the compressor shuts down the humidity increases to 85-88% and when i on the blower of the machine the humidity is between 82-88% the power to my machine is given through a 1kva ups and i guess the power is stable and there is no short mostly...

@dan

its a small ic on which following details is written "EFEB 8918 3430 U31"

and i don't have any schematic if anyone can provide me with the diagram of the motherboard it will be helpful

and if you want i can arrange a clear pic of the the burnt IC...

waiting for positive reply.

[Dan Hintz]

its a small ic on which following details is written "EFEB 8918 3430 U31"
When you say "written", do you mean typed/handwritten or imprinted onto the chip itself? I ask because your description included the schematic-based descriptor U31, and this will never be imprinted on a chip from the chip manufacturer.

If typed/handwritten on a sticker, is that sticker covering a window? If yes, that's an EPROM. Look for other markings on the chip under the sticker. If it is, this chip is NOT the cause of your problem, it is somewhere else up the line.

[jay vyas]

hey am not sure but mostly it was printed on the board next to the chip and the chip is located near a intel chip on the board...

[jay vyas]

@dan

so finally i checked the board and here i am with the details as shown in the following diagram U31 is printed near the IC on the motherboard and this same IC has burnt 2 times on 2 boards and on the first board IC the details was printed "EFEB 8918 3430" and near the IC it was printed U31 on the motherboard and on the second IC it is printed "0516 3430 EFE 9532" and near the IC it is printed U31 on the motherboard and this IC id near other 2 ics D18 and C133

please please please help me find out where the mistake is...whats the reason for this IC to burn before this IC burbt the X axis worked abnormally and the IC burnt out...

here i attach a small diagram made by me:-

97155

[Vishal Sharma]

Hi I have many of Epilog machines actually one of the best in the world and I also faced same problem but I found it was the problem of static charge from my UPS due to some faulty circuit and improper earthing, check all that. I am sure Epilog people in india will support and replace that, they are quite good , Best of luck

[Dan Hintz]

Jay, post a close-up view of that area of the circuit board (please make sure it is clear, not blurry),large enough so the lettering is readable, and try to include some of the surrounding circuitry. D18 is a diode, C133 is a capacitor. I'm trying to determine the function of this circuit, which would lead to a more useful diagnosis.

The change in markings from one IC to the next leads me to believe it might be a custom-marked IC, an FPGA, a power component such as a stepper driver, etc.

[jay vyas]

@vishal

i had called the ups technician and he checked the output power of the ups and earthing also and he told the ups output and earthing is perfect, how did you check that your ups is sending static energy??? does epilog people have any trained engineers??? where are you located in india? and is your computer also connected to the same ups with the machine if there is a problem in the ups will the computer also get spoilt or diabled as my computer and machine are on the same ups but my computer never gave a problem...??

and the ups is not purchsed from the epilog people it is a liebert make 1kva ups and the problem is that each time my board burns i get a replacemant on time but i have to pay custom duty worth 26k and i have spent around 75k for three motherboard replacement that too in three months and now when i asked them they told its a humidity issue am very much confused where the problem is...

@dan

ok will do it and post the pics...in sometime

[Marc Myer]

I keep my machine in a shop that has no air conditioning, and our weather here in Hawaii also has very high humidity. From what I understand, Epilog has engineered their machines to handle high humidity environments.
I've only had my machine for less than 2 years, but have had no problems thus far.
Please keep us informed about your machine--we all can learn from your experience.

[jay vyas]

@marc

thanks for your reply but i don't know why but epilog company agent here in india says that epilog comapny has told him this reason that "due to humidity the board burns???"

@Vishal waiting for your reply

[John Noell]

I do use air con in the laser shop but the weather here in Fiji is WARM and HUMID. We overlook the sea from the workshop. Our power is also pretty flaky. I use surge protection through a UPS but it does not go through the battery backup part. (Epilog seems not to have concerns about using a UPS.) I worry, but have had no problems so far. The power did fail while cutting one time but all was okay when the power came back on.

[jay vyas]

@john

thanks for your reply i also use a ac but still the temperature goes down to 18 degrees celcius but humidity is between 75-88% and epilog agents here in india tell us to use a 1kva online ups compulsory and what is a surge protection and how does it work will i get this thing in india if anyone knows?

@vishal waiting for reply

[John Noell]

I run my shop at about 26C. Humidity is about same as yours. When I asked epilog USA about using a UPS they had no recommendations and seemed not to think it was necessary. On the APC 650VA UPS I use for the computer (because hard drives often die on low voltage) there is one outlet/powerpoint that does not have battery backup but does have surge protection. That is what I use for the laser. FWIW, an electronic engieneer gave me a LONG explanation as to why cheap surge protectors (like in powerbars/powerstrips) are USELESS. He said a real surge protector for single use (i.e., burns out and cannot be re-used in the case of a surge) would cost at least US$100.

[jay vyas]

@john

thanks for your reply but as of our indian epilog agents say ups is compulsory and secondly they give me a reaon of my motherboard ic burning is due to humidity that too they say usa epilog company told them so i can't understand whee the problem is i have lost 3 motherboards and paid 26k custom duty per board still i didn't get any solution why my board's ic is getting burnt...

please help me findout

@dan
i'll post the image soon

@vishal
waiting for reply

[Vishal Sharma]

We face this in only one of three machines we have saperate ups for computer, we are in gurgeon near delhi. I have no idea how to check ups and it was done by the ups supplies. But last two years we have no problem

you are right duty is a big problem with warrenty parts, actually warranty parts should come on very little invoice value

[Dan Hintz]

FWIW, an electronic engieneer gave me a LONG explanation as to why cheap surge protectors (like in powerbars/powerstrips) are USELESS. He said a real surge protector for single use (i.e., burns out and cannot be re-used in the case of a surge) would cost at least US$100.
I second this assessment. And even that "real" surge protector will still be useless against a direct strike... there just isn't much out there that can survive kA and kV in one short burst.

[Rodne Gold]

The problem with power in underdeveloped countries , like where I live , South Africa , is brownouts , sudden losses , surges when it comes back on , bad wiring , unequal phases and so on.
The Power supply in the machine should handle this quite adequately , but to protect yourself , get a UPS with batteries , the kind that converts AC to DC , and then DC to AC - Ie you isolate yourself COMPLETELY from the mains. These are expensive , and you need a 1.5 -2 KVA unit.

However I don't think it is this or humidity thats blowing the IC , I would like to see a pic of this IC as I suspect its a driver IC
Does it have a metal plate/tab with a hole ? is it screwed into a metal heatsink with heatsink paste? You say your X axis goes wrong before the IC blows , thats what makes me think its a stepper/servo motor driver. If it has been replaced and the wrong heatsink paste used , or no paste used etc , it can easily blow again.
I would mount small fans like you get on computers somewhere and let em blow on the IC in question , cooling it. Make sure all the components on the motherboard are dust free , that there is good ventilation round the motherboard and make sure its the same with the power supply components that go to the motherboard. Make sure all cables are securely plugged in.

[jay vyas]

@vishal

thanks for your reply

@Dan

thanks and will be posting the image by today

@rodne

i have a 1kva online ups with battery back-up of 45mins and it converts ac-dc and dc-ac

my x-axis mothor has not been replaced but my motherboard has been replaced three times and each time this ic burns and that too it burns after working for a month do you think that there is a problem in the x-axis motor? once i had changed my y-axis motor but after that my macine worked fine for 6 months the problem of this motherboard burnout has started from the june-july months the months of rainy season...

how will i come to know please help me findout where the problem is as laser lab india people have no proffessional engineers here in india...

it doesn't have any metal plate/tab its a black colour ic a metal like thing is next to it C133

and about cooling how will it be possilbe to blow a fan the motherboard inpacked from the sides where to add fans for cooling

will post the image today...