[superstar]

Ok now I know this isnt computer related but it is in a sense. My friend is actually studying to pass some dental tests in America. He is from abroad but needs to pass some tests to legally run his own business in the States. He borrowed a small dental solution mixing machine as seen here from another friend at a clinic:



Source: http://www.kerrdenta...lloys-optimix-2

It's worth about $1500... & well he plugged it in and it was working fine for about 20 minutes. Than all of a sudden he also turned on another piece of equipment that uses a fair amount of wattage at the same time, on the same power strip. Something he had never done before because he would always run appliances independently by making sure other appliances were off on the same power strip. Turns out that after turning on the second appliance, and leaving the mixer on it duffed up the mixer. Now the mixer led screen shows "XXXXXXXXXXXX" [just the letters X across]. It lights up, just doesn't show the O/S as it would normally. The machine gets power, and seems to work, but the O/S isn't showing up.

He asked for my help since I know a lot about computers. In my opinion turning two high powered devices on at the same time, on the same power strip. Probably caused a brown out dip in electrical current which wiped the O/S from the black onboard nand chip/rom chip or what have you. I referred to the manual and all it said about a non working display is to check the fuses. Mind you the screen isn't blotchy, isn't damaged to the eye, it's just not showing the operating system only the letter "X' across the whole screen.

This is what the screen would normally look like working:



I took the fuses out and they seem to be fine. They're not charred, and the wire isn't melted, or broken away/separated. It does seem as if the wires in both fuses are somewhat slanted, but they look like they're connected on each end of the fuse correctly.

The two fuses are rated 0.63A 250V for 115/120V American Standard use, and look kind of like this with the wire slanted in the middle:



As you can see the wire in the google example is slanted but still connected. The photo below is a style of fuse I have usually seen with the wire directly centered in the middle:




I took the unit appart, and it's fairly basic looking inside compared to a computer. It looks like basic calculator style parts lol [jokes]. Anyways there is no charring on the internal motherboard, capacitors look fine, and the unit powers on as I said before. I think the unit lost the O/S in during a power fluctuation. That' my opinion... I have lost the onboard rom/nand O/S off an external hard drive enclosure before. Though I was lucky enough to find it through google and flash it back to the external enclosure. Which worked! But this is a dental device and you won't find that online, nor will you find a way to connect it to a pc obviously.

So my questions are:

1. What do you think happened?

2. Could buying two new fuses make the unit work? If so what are the chances percentage wise?

3. I know little about fuses, but from my understanding if one is done for the wire would be melted, or split. Could it be semi functional yet still power the unit? I wouldn't think a semi damaged fuse would even allow power through.



Thanks


Any help for this $1500 mess would be helpful.

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Unless you test the fuse, you can't be sure that it is actually blown. Sometimes it is obvious, other times it is not. You can use an ohm meter to test or just try replacing the fuses to see if it does anything different. If the fuses are the same, then you can try swapping them to see if anything is different.

Are there only two fuses?

Yes, it sounds like it is not loading the OS, but the question is why. You might also call the company and ask them for troubleshooting procedures, although they might say to send it in.

[Kemasa]

Unless you test the fuse, you can't be sure that it is actually blown. Sometimes it is obvious, other times it is not. You can use an ohm meter to test or just try replacing the fuses to see if it does anything different. If the fuses are the same, then you can try swapping them to see if anything is different.

Are there only two fuses?

Yes, it sounds like it is not loading the OS, but the question is why. You might also call the company and ask them for troubleshooting procedures, although they might say to send it in.

[superstar]

@Kemasa Yes there are only two. I didn't see any inside the actual unit. Ya they want us to send it in in order to make money [$300]. They didn't even tell us to check the fuses. Which goes to show that they just want money. I will try switching them in opposite positions right now. [eg: left one right, right one left]

Edited by superstar, 01 June 2012 - 11:57 AM.

[superstar]

Tried putting them in opposite positions but it does the same thing [Ie: left one right, right one left]. Unit powers on, yet the LED screen shows the letter "XXXXXXXXXXXX" <- like that when you turn it on. The screen lights up though...

[Kemasa]

There can also be fuses which are soldered in and may not look like a fuse to you. These are typically smaller, but often the board is marked with the fuse symbol.

Fuse symbol

It sounds like the display is starting, which can be separate, but the unit itself is not. It could also be that it is not finishing to load the OS.

There is no difference at all when you switch the fuses? You mention the screen lighting up, but I am not sure if it does that the same both ways.

You have left it unplugged for 15+ minutes, correct?

It is also possible that the machine is in a confused state, so if you can find a reset procedure that might work. As an example, I was working on some plumbing and had to turn off the water, but the dishwasher was on. It detected the loss of water and got an error and would not automatically clear the error. The company said that they would have to send someone to look at it, but I found the required paperwork (hidden), which had the error codes and reset procedures. Once it was reset, it was fine, but disconnecting it from power had no effect at all.

In a slight defense of them, it is often easier and safer for them to just have you send in the unit. If the fuse is blown, there is typically a reason and if the person replaces it with the wrong fuse, then other problems can result (fear of lawsuits).

If you can find out what it means to have all the Xs, then it might help lead to a solution. There could be on-board fuses and/or a means of resetting the unit.

[Kemasa]

FYI:

The government price on the unit is $441.45, retail was $935 (at least when this document was written):

gov price

One place I looked at had it for $988. It also appears to be a discontinued unit.

You could also check to make sure that all the voltages are working, if you have a meter.

[superstar]

Thank you so much for your help. I appreciate you actually looking into this matter.
I just opened it up again to double check if there were any extra fuses on board, apart
from the two that come out of the removable tray behind the machine. Well everything
inside looks completely fine. I guess the brown out in electricity duffed up something
somewhere. You can still input settings on the keypad and the machine still works. You
just can't see what settings your pressing on the LED screen.

After you turn the machine on all it does is say "XXXXXXXXXXX" on the screen, and that goes
away after about 3 seconds. The screen does stay lit up green though. Yes I'm not surprised
that it's discontinued. The manual states a date of 1999. Darn thing was supposedly bought
new and never used though. Until he used it... I have no meters to test any continuity, and
such. I guess it's either use it without the screen telling you what settings your on [which
is hard to do]. Or just find another one...


Thanks again

[Kemasa]

That sounds like the main part of the machine is working, so it is just lacking the communication from the main system to the display. It might be that something just failed and it happened at the same time.