eMate 300 not working - "dead"

[Classicman]

Hi dear friends!

I recovered a Newton eMate 300 with its original power supply through a friend of mine. It's fantastic!!!
I can define the cosmetic condition as being like new!
But... connected to electricity it shows no sign of life... nothing... not even its green LED lights up.
I can tell you that I checked its power supply with a multimeter that it correctly delivers its 7.3/7.4 volts.
I also removed its internal battery pack (NiMH) because I think it is definitely exhausted but nothing, nothing changes.
I even held down its little "reset" button on the bottom of the chassis but nothing.
I researched on the web about this model of Newton, and I noticed that on its logic board there are no electrolytic caps which over time can lose the much feared electrolyte.
This "apparent death" should not be due to capacitors of this type...
Before starting to disassemble the very delicate bondi plastic of its chassis, can anyone help me with some tips? do I need to check something specific?

I thank you all in adavence! 

 

[CTB]

Dumb question but do you have the sound and contrast sliders turned up? I have been caught out my this before. I had a unit which didn’t show the green or orange power light but was on. I just could see or hear it.

 

[Classicman]

Thanks a lot for your reply CTB! yes, I've checked sound and contrast sliders.
My eMate don't show any sign of life... no sound, anything on LCD, no green/orange power light...

 

[CTB]

Try this specific sequence if you haven’t already. Plug in the AC adapter, wait about 30 sec, hold down the power key, press the little reset button on the back while still holding down the power key for another 30 sec. Release the power key and hopefully about 1 minute later you should see the “Erase All Data” dialog box, select “YES” and it should restart from there.

I have used this sequence a few times after adding or removing a RAM expansion module as the eMate sometimes just doesn’t want to start.

 

[beachycove]

Just to add to an excellent suggestion: the “Erase all data” in the previous post means to reset to how the machine came from the factory, rather than to blank everything out. NewtonWorks et al will still be on there. Also, don’t interrupt the device if and when the erase starts!

 

[splorp]

It’s so odd that you’re not even seeing the power indicator light up. To me, that says that there is something amiss internally … perhaps a dislodged connector.

As for disassembly, the eMate casing tends to be more robust than the beige Apple plastic that we’re used to seeing snap apart.

 

[CTB]

I opened a virgin eMate I got on eBay yesterday. The plastic is amazingly flexible compare to its Mac contemporaries. Just don’t forget the screw in the handle. It is hard to see as the rubber plug that covers it the same colour as the unit.

 

[CTB]

I have units where the light never comes on and still power up. However, I agree it is odd. Given the other symptoms it does sound like a power issue. You say you have tested the barrel connector on the power brick, next I would open it up and see if that power is making it through the female barrel connection on the unit.

 

[Classicman]

Thank you all for all the precious tips!
I've tried the tip suggested by CTB "Plug in the AC adapter, wait about 30 sec, hold down the power key, press the little reset button...".
Nothing changed...
In the next few days, as soon as I have some time, I will have to disassemble the eMate and check the power supply zone (connector, soldering, burnt components...).
I just hope it's a minor problem because as I was saying this recovered eMate is in really great shape! I'll keep you updated and thanks again to everyone!

 

[CTB]

Thank you all for all the precious tips!
I've tried the tip suggested by CTB "Plug in the AC adapter, wait about 30 sec, hold down the power key, press the little reset button...".
Nothing changed...
In the next few days, as soon as I have some time, I will have to disassemble the eMate and check the power supply zone (connector, soldering, burnt components...).
I just hope it's a minor problem because as I was saying this recovered eMate is in really great shape! I'll keep you updated and thanks again to everyone!

Persevere. I have opened approx. 20 of them and never had a motherboard fail. Lots of display cables being cut and hinges breaking but never anything that stopped it working apart from a corroded barrel connector that was easy to diagnose and repair.

 

[Classicman]

dear CTB, thanks a lot for your encouragement! It's always good to feel encouraged!
You are typing to the right person, I know well what "persevere" means in these cases and with electronics. Consider that I spent almost a month behind a Mac Classic where I first performed a complete recap (analog board and logic board) and then I went crazy because it kept giving me the serious vertical collapse problem... but thanks to a precious help of a member of 68kMLA in the end I won!

 

[bibilit]

Maybe a fuse gone bad, but you can remove the battery and try again with the PSU only.

Mine is unable to work with a battery fitted, but works ok when connected to the wall.

 

[Classicman]

Hi dear friends!
I'm sorry for my silence but during this period work doesn't leave me free time to dedicate to repairs... anyway I disassembled the eMate and nothing... nothing seems out of place on the motherboard, no burnt components. I checked the tracks of the power supply connector with the multimeter and found the positive and negative short-circuited... I desoldered the connector because I thought it was the connector's fault but no... even without the connector the positive and negative on the logic board are short-circuited. Which component will be burned/shorted? mmm... I really don't know where to go to look also because there isn't information about eMate repair on the web... Greetings to everyone and thank you in advance for any tips! 

 

[beachycove]

Stupid question, but needed at this point: You do have the ROM installed in its slot, do you? Lots of old machines have been cannibalized for parts.

 

[bibilit]

Not easy to help you at this point.
Finding the short is only possible by removing components one by one until is gone.

Any capacitor nearby ?

 

[Classicman]

Stupid question, but needed at this point: You do have the ROM installed in its slot, do you? Lots of old machines have been cannibalized for parts.It

It's not a stupid question! but the ROM is installed in its slot.

 

[Classicman]

Not easy to help you at this point.
Finding the short is only possible by removing components one by one until is gone.

Any capacitor nearby ?

Thanks for your help! but no, any cap nearby the power input port.

 

[aladds]

I could imagine there's a protection diode on the input which has failed - possibly due to someone connecting an incorrect power supply.

When the eMate works, you should get a green LED as soon as the power supply is connected, then this changes to orange just before it boots. From memory this happens even without a battery installed. And if you have a bad battery, I'd remove it.

 

[Daxeria]

You're likely already aware of this, but the eMate has a design flaw time bomb where a spring eventually works its way loose and punctures the display cable. It can be fixed by securing the spring with a washer.

 

[Classicman]

I could imagine there's a protection diode on the input which has failed - possibly due to someone connecting an incorrect power supply.

When the eMate works, you should get a green LED as soon as the power supply is connected, then this changes to orange just before it boots. From memory this happens even without a battery installed. And if you have a bad battery, I'd remove it.

I checked everything I could check dear friends, but clearly my poor knowledge of electronics doesn't allow me to bypass my problem.
I really don't know what to do!
I just have to wait to find a "new" motherboard to replace my faulty one...