RTW PortaMonitor 1064

Neeno · May 25, 2013

Hey Guys, I've got one of these units...
It seems to be fairly old...
When I turn it on it seems something is happening.
The backlight of the display seems to work... I can barely see the logo on the display.
The unit worked randomly 3 times over 100 trials...
I've opened it up... No signs of faulty parts inside the unit, at least the main pcb, I didnt't opened the screen yes.

Has anyone fixed one of these units?
Can anyone help me please ?

abechap024 · May 25, 2013

Recap!

I would try it at least

Neeno · May 25, 2013

Really ?
There are only 3 electrolytics and they seem to be in good shape.
I removed and measure one... and it is good.
So I stopper raping this overpopulated full of smd double layer pcb.
But I'll give it a go.

There are 2 voltage regulators (2575s) and a TIP117 on the main board.
Maybe the TIP117 could be faulty... But I don't know how to check it...

abechap024 said:
Recap!

I would try it at least

matthias · Jul 5, 2013

Hello, I nearly have the same problem with my 10689 Portamonitor so I think it's quite a common problem...

http://www.youtube.com/watch?v=bcQ5QrvCPk0

could you fix your unit?

[silent:arts] · Jul 5, 2013

Most times it is the display itself.
Even RTW have no replacement parts anymore, nor will repair them ...

culteousness1 · Jul 5, 2013

matthias said:
Hello, I nearly have the same problem with my 10689 Portamonitor so I think it's quite a common problem...

http://www.youtube.com/watch?v=bcQ5QrvCPk0

could you fix your unit?

From your video, it seems more like a digital problem.
The µ-Controller or FPGA goes into reset again and again and again and...

This can have several reasons. I would check the power rails first.
Without a schematic at hand, I would guess that there are at least two rails.
One 5V rail around the LM2575S-5.0 and a other 3V3 rail regulated with another IC.
Next thing would be to scope the Controllers reset pin or the brown-out detector.

As your are located in Germany, this article may help to find the correspondent IC.
If you have this unit open already, you may search for the Controller's part name.

Best,
Carsten