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P2 module malfunction. Is it totally dead?

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cte

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P2 module malfunction. Is it totally dead?

Post18 Feb 2015, 15:17

Hi all. :)

I don't suppose there is anything I can do about this dead/malfunctioning p2 module? When batteries are inserted the display stays light (as shown in the picture). Pressing the button does nothing. The battery compartment looks clean, but the inside of the back case looks corroded or possibly burnt?

I can't think there is much to try to get it working. :scratch:

Any thoughts would be most welcome.

Cheers. :D

Edit: as a last resort, would hanno's sasm procedure work on the module?

Edit 2: I don't know whether this has any significance, I just placed the faulty module inside a different p2 body and the first digits light up instead of the last digit. Pressing the button still does nothing, it just seemed strange when the different section light up.

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Edit 3: So, removing the battery and putting it back in again seems to change the display. As far as I can tell, it doesn't seem to display anything other than these few:

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Last edited by cte on 18 Feb 2015, 21:16, edited 1 time in total.
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bruce wegmann

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Re: P2 module malfunction. Is it totally dead?

Post18 Feb 2015, 21:12

You have missing segments, partially-lit segments, no oscillator. I'm calling this one...not repairable. I've seen the dark film on the inside of the caseback before; it does seem to be a byproduct of leaking batteries.
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767Geoff

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Re: P2 module malfunction. Is it totally dead?

Post18 Feb 2015, 21:17

1: the Quartz crystal is not oscillating and therefore not sending the prescribed interrupts to the PCA. This causes the watch to lock onto a single digit.

2: the changing of the case did not cause the digit to jump; it was the power interrupt that caused the digit to change. Try removing and inserting the batteries while keeping it in the same case and see the digit position change.

3: it looks like there is a display problem as the digit appears to be a 2 with a segment of dots not displaying.

4: someone probably attempted to solder the butterfly battery contact on and applied too much heat causing the discolouration. Also there is some battery corrosion. Batteries do not necessarily leak fluid but can outgas. This gas is also corrosive and although the module looks clean it may have suffered corrosive damage to the IC.

5: SASM module would work as well and I have a couple, also this module will work: http://www.pulsarledtime.com
Both are excellent and mimic the original modules, in fact using the original displays.

Geoff
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cte

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Re: P2 module malfunction. Is it totally dead?

Post18 Feb 2015, 21:29

Thank you. :)

Yes, I have been playing around with the batteries earlier (see edited post above) and it indeed shows up different digits etc. I can't really tell if any of the segments are missing as the rows that light up seem complete, but the 2 and 9 (possibly an 8?) might have the lower left line missing.

When I opened the watch for the first time today the old original RW11 batteries were still inside. They do not show any signs of corrosion, but the gas thing you mention could be the culprit for internal unseen damage.

I have a spare Quartz crystal. Is it worth trying to replace it in the module? It's a possible fix?
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Re: P2 module malfunction. Is it totally dead?

Post19 Feb 2015, 00:38

If you have more than 2 digits lit at the same time, then the oscillator is working. I would assume, that the module paid the dept of nature and it´s a better investment to buy a beer then to change the quartz. :-D
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bruce wegmann

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Re: P2 module malfunction. Is it totally dead?

Post19 Feb 2015, 00:48

The RW11 is the equivalent to the 355. These haven't been made since the mid-90s, so those batteries were likely in there at least 20 years, so there was plenty of time for corrosive material to work its' evil. Actually, static electricity can do more damage, in a microsecond, and leave a module looking absolutely pristine; I would guess as many Pulsars (LEDs in general, actually) fell victim to that as leaking batteries.
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cte

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Re: P2 module malfunction. Is it totally dead?

Post19 Feb 2015, 01:48

Thanks guys. :-)

Just to clear something up, for myself lol... Bruce, you have mentioned before about static. Now, every time I open a digital watch (Casio, seiko, etc) I am worried about static and the damage it might do. :o Can static damage all types of digital modules? Can simply opening a p2 and replacing the batteries (taking care not to touch the module) cause damage if not grounded? Sorry, I am a newb with this kind of stuff and it has been on my mind for weeks. :oops:
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bruce wegmann

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Re: P2 module malfunction. Is it totally dead?

Post19 Feb 2015, 07:11

Anything that uses CMOS circuits is vulnerable, to one degree or another. Modern CMOS is better engineered and protected, but the vintage stuff tends to catastrophically break down above 15V or so; even mild static charges carry hundreds or even thousands of volts, and so are deadly to early LED watches. I never open a watch unless I'm either grounded, or the humidity is above 65% relative (the air becomes conductive enough to prevent static charges from forming; I get a lot of work done on foggy or rainy days). Anything that could put an unequal potential across the battery terminals should be avoided.
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cte

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Re: P2 module malfunction. Is it totally dead?

Post19 Feb 2015, 09:44

Great. I see. Thank you Bruce. :-D

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