battery replacement question

[Tygre]

Hi there!

How are you? I also replaced the battery of my Amiga 4000, but I could net get it to work!? The previous battery had leaked, do you think something might be broken? Did I miss something? :-(

Thanks!
Tygre  :-)  

[Tygre]

@ Tygre:
If the "save" button in the Time Preferences is ghosted out, it means the system cannot see the real time clock (RTC).
If this is the case, then probably one of the PCB tracks around the RTC have gone open circuit due to corrosion.  Sometimes the data latch U177 can die due to corrosion damage.


If you have the trouble of the RTC working, but not remembering the time due to the battery not charging up, then one of the tracks that charge the battery (via the +12V line) is probably open circuit.


I have schematics and stuff you can use if you have a reasnoble electronics knowledge.  The circuit is very simple.

Hi Castellen!

Yes, 9 years ago, I am back! :-)

Could you post or send me the schematics, the battery works but the "Save" button is ghosted so something must be wrong...

Thanks!
Tygre

[Tygre]

A revival of a 2003 thread; talk about scraping off the dust!

Anyway, you'll find all the information you need on my webserver here.

Isn't it cool ;-) That really tells something about the Internet never forgetting (forgiving?) anything...

Anyway, thanks a lot for the link! I am going to check it out and I'll keep you posted (hopefully in less than 8 years...)

Cheers!
Tygre

[Tygre]

A revival of a 2003 thread; talk about scraping off the dust!

Anyway, you'll find all the information you need on my webserver here.

I started to check the resistance measurements of the U177 following your great page and here are my results so far:

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Resistance measurements on U177 (latch)
Pin 1 1k ohm between pin 1 and 16 (+5V)            OK
Pin 2 10k to ground,                               5k
        connects to U178 pin 7                       NO
Pin 3 2.5-3k to ground,                            10k
        connects to U175 pin 6
Pin 4 2.5-3k to ground,                            10k
        connects to U175 pin 7
Pin 5 10k to ground,                               4k
        connects to U178 pin 6                       5k
Pin 6 2.5-3k to ground,                            2k
        connects to U175 pin 8
Pin 7 10k to ground,                               2.5k
        connects to U178 pin 5                       YES
Pin 8 less than 1 ohm (approx) to ground           OK
Pin 9 High resistance (greater than 1M ohm),       3.5k
        connects to U150 pin 72 (via 47 ohms)
Pin 10 10k to ground,                               3k
        connects to U178 pin 4                       YES
Pin 11 2.5-3k to ground,                            NO
        connects to U175 pin 9
Pin 12 not connected
Pin 13 not connected
Pin 14 not connected
Pin 15 not connected
Pin 16 Less than 1 ohm (approx) between U975/U976
        (located next to U177) pin 16 (+5V)


So, it seems that either I am missing something or my U177 is really destroyed! What do you think? What else could I test to find what is wrong (including me!) to get back my clock :-)

Cheers!
Tygre