Continue to Site

Welcome to

Welcome to our site! is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Is this IC broken?

Not open for further replies.


Newbie level 4
Jul 6, 2015
Reaction score
Trophy points
Activity points

I have a sensor what I think might be broken. It has IC what has two bulges in it. Do you think its broken or is that just for hiding IC type?


It certainly looks unusual but when small ICs like that overheat they usually show scorch marks and there is a single bulge above the silicon in the center of the top face. That looks more like the glue dots used to keep components in place prior to soldering. Possibly the manufacturer has used glue dots to deliberately obscure the part number or to indicate a revision of the board design or IC firmware. What is the board? Is it possible they are glue and something was intentionally stuck to the IC but has come adrift, for example if it is is temperature sensor was it glued to a surface to improve heat conduction?

It's sensor for Canon ipf 9100 printer. Nothing was stuck to the IC, I am sure of that. Is there any way to know it is glue? It certainly seems like part of IC.

You might be right of course, it's difficult to say from 2,000Km away :)

Try scraping it away, if it's glue you should be able to remove it back to the original epoxy of the IC. If the bulges are 'blisters' from overheating, the underlying epoxy will be britle and powdery, you would see (feel) a very different texture underneath them. You would probably expose obvious holes going deep into the epoxy and be able to detect the scent of burned plastic.

I scarped them and they go inside the IC. I also tryed to scrape flat area and knife didnt penetrate material same way.

I have a sensor what I think might be broken. It has IC what has two bulges in it. Do you think its broken or is that just for hiding IC type?

I've examined all your posts, you seemed to have forgotten to mention whether or not the module is functional.

Is there an issue with the module? If not, leave it be.

If the module is nonfunctional, then obviously there is a component which is either damaged or simply failed.

However, if you find the component is damage and plan on possibly replacing it, you will need read the part identification markings on the top of the device or have a schematic available to determine a proper replacement. So take care not to remove the identification markings, with all that scraping, if you do not have access to a full schematic of this particular module.

After examining the images you've posted, the "bulges" appear to be too perfectly circular to be cause by internal damage within the IC, although almost anything is possible.

Perhaps if you could state whether or not the module is functional and if not how does it fail, it might shed some light on the topic.

I'm not sure if the sensor is the problem.

It's really hard to test it when I dont have any schematics about sensor (Cant probably get it anywhere) and those bulges covered IC type. As I said I carefully scraped where the bulges were and now I see metal inside IC.

If it was glue I think I could not carefully scrape it until I would see metal.

New sensor is like 100 euros with postage, I'm going to order it now. I agree that those bulges look too "nice".

New sensor is like 100 euros with postage, I'm going to order it now.

Yes, they typically have you over a barrel when it comes to purchasing replacement parts.

Is this an imagePROGRAF iPF9100 printer/plotter?

Have you Googled for new/refurbed part suppliers, if they carry the part, they can typically be a fraction of the price quoted by Canon.

In any event, best of luck.

Listen to Bigdogguru - he's a genius. (and he probably has my address to send financial help for praising him :-D)

The fact that you noticed a difference in the consistency of the epoxy and uncovered metal is a sure indication it is truly dead. Do yourself a favor though, if you are getting only a replacement IC, before fitting it but with the old one removed from the board, measure the resistance across the LED joints. Make sure they have not gone short circuit. It looks like it may be a sensor to detect whether paper is in transit through the mechanism so it might be in charge of switching the LEDs on and off. If one has gone short circuit it could immediately damage the replacment IC.

From the location I'd say the bond wires got fused from
some overcurrent event (possibly, the two blisters are
the fault current path through the part). Question is, what
will be different for the next victim?

Probably better luck finding the board at surplus / eBay,
than repairing it (anytime you have a catastrophic damage,
there's a good chance of "walking wounded" neighbors).
Listen to Bigdogguru - he's a genius. (and he probably has my address to send financial help for praising him :-D)

What's that address again?

As both Brian and Dick bring up excellent points, it's not uncommon to see such a replacement part simply go too up in smoke as damage may extend to other boards/components throughout the entire system, particularly if the power supply has been damaged. You might want to use a multimeter and check the power supply outputs to see if they make sense and then trace these connections throughout the system, carefully examining the other boards for damage, before replace this board/part.

As both Brian and Dick alluded to, you may want to keep an eye on eBay for a structurally damaged unit, but still electronically intact, which you can then turn into a parts cow. It certainly is not uncommon, for large format printers/plotters to be structurally damaged during shipping or liquidation, the external case maybe broken/cracked or missing a door/cover, however internally most of the parts are still intact and viable.

Judging by the opto emitter symbols , it looks to be an End Stop sensor with a stepper motor driver to stop overtravel or find datum position.

So inspect mechanical and optical paths for faults. Does it smell like it looks? Burnt epoxy....

That sensor is called multi sensor and its located in carriage unit near the paper. It detects leading edge and width of the paper. It consist of four leds (two infrared) and two light receiving sensors. There are two pcb's inside carriage unit, headrelay and carriage relay. I put picture here if it might be usefull somehow.

When I turn machine on, it makes some sensor checking and then it gives multi sensor error. That error didn't always appear same way. First it just appeared randomly when I was printing but now I cant get printer started all the way at all.

As it can be seen by picture wire goes in headrelay pcb from multisensor. Headrelay pcb has multisensor control IC what generates led control signals and makes gain adjustment for the multi sensor.

When I have enough time I will try to measure wires going inside the multi sensors connector.

- - - Updated - - -

There was no burnt smell at all, at least I can't smell any, IC is very small tough. Headrelay pcb's multi sensor contol IC looks fine when I checked it by eye.

I came across several multi-sensor boards for the imagePROGRAF iPF9100 printer/plotter, available from new/refurb printer/plotter parts deals in the $40 to $60 USD range. I suspect you might find even a better price on eBay as Dick pointed out and, of course, there is always the parts cow option.


They are cheap in USA, but when I look them in Europe prices are with postage 80-100 euros to Finland. Trying to find shop what has them in stock and have fast shipping method available. I dont like waiting parts :D

Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to