Apollo 1240 Battery not holding time

[StompinSteve]

Hello all,

The Apollo 1240 I purchased recently had a missing battery so I bought a Panasonic VL1220 HFN 3V 7mAh, the same as StevenJGore uses in this thread: https://eab.abime.net/showthread.php?t=41629

I measured the voltage of the battery when I took it out of it's packaging: 2.988 V
I then soldered it in, in the exact same way as StevenJGore has (see his photo above). The + and - are written on the board, the orientation of the battery is therefore clear.

Before I inserted the card back into the trapdoor slot, I measured the voltage again against the two solder-points on the other side of the board (where I soldered). Still 2.988 V.
I then had the Amiga on for a couple of hours to give the battery time to charge.

However, when I set the date and do "setclock save" the time is maintained during soft reboots but is always reset to 2007 when I power-cycle. It behaves as there is no working battery on the Apollo...

Any ideas what could be wrong?
The previous owner desoldered the battery and cleaned the board up. The Apollo runs perfectly stable. I have no other issues outside this battery not doing it's job.

[StompinSteve]

Update: I checked for continuity on the board. The - of the battery successfully connects to other parts of the PCB where there is a negative terminal.
The + of the battery has continuity with other parts, for example the positive terminal where the + wire of a fan is normally soldered onto.
In other words, I'd say my soldering is good.

I'm looking for schematics of the Apollo 1240 but all links I've found so far are dead links :-(

[Jpor]

Originally Posted by StompinSteve

Update: I checked for continuity on the board. The - of the battery successfully connects to other parts of the PCB where there is a negative terminal.
The + of the battery has continuity with other parts, for example the positive terminal where the + wire of a fan is normally soldered onto.
In other words, I'd say my soldering is good.

I'm looking for schematics of the Apollo 1240 but all links I've found so far are dead links :-(

Had a similar problem with an Aminet Hawk accelerator card. Found that 2 pins were missing on the RTC chip. As soon as I soldered on W new legs all was good. I take it you’ve checked the RTC clock chip? Also try booting up Amitestkit off Aminet and checking if the RTC clock is being detected.

[StompinSteve]

TestKit reports the RTC as a MSM6242 (detected at 00dc0000).

I've found this dodgy repaired area on the board (bottom of screenshot). Those 2 pins on that F74 that are "bodged" together, are supposed to be connected via the PCB and they do have proper continuity. I guess that "repair" was done due to battery-leak damage because normally, the PCB has a trace to connect those 2 pins. That trace must have been damaged.

Before I sound like I know what i'm doing, I have no idea what a F74 Chip does despite googling it.

I checked the other pins of that F74 with the help of a partial PCB Diagram of the Apollo 1240 that i've found and the pins seem to have continuity with whatever they are supposed to be in contact with (as good as I could).

That black blob at the bottom is suspicious though. It looks like it could contain a small component. But what and why? I've seen no other Apollo 1240 or 1260 boards with such a "modification"..

[StompinSteve]

Ok i think I'll need to send the board in as this is over my head. I need someone who know's these Apollo 1240's well. Having the schematics would help but I have the impression only Jens Schönfeld and Mr. Hertell (Chucky) have these schematics.

Is Chucky still accepting repairs? I'll send him a PM.

Update: Mr. Hertell told me he does not have the time to accept repairs.

[jbenam]

The F74 is used as a clock divider. There is no component under that epoxy, I think it's just a wire with some insulation on it.

That's how it is on a genuine PCB as well.

I would check the crystal (the little round thing) next to the RTC chip.

[Chucky]

Sadly I do not do any repairs at the moment.. too busy with budilin TF1260s and doing PCB swaps.


that 74F74 on pictyure above only handles cpu clock. RTC is at other side of the board, the OKI Chip.

check that the positive side of the battery goes to the bottom pad of the 1K resistor right of the 32768Hz oscillator (and the cap that is on the outer end of that block)


top pad of that 1K resistor shold go to pin 18 of the OKI chip.

[StompinSteve]

Originally Posted by jbenam

I would check the crystal (the little round thing) next to the RTC chip.

How do I do that? All I can do is check continuity with a multi-meter and tell you that the clock runs perfectly normal (not too fast or slow) while the Amiga is running for many many hours. Does that "prove" that the crystal is ok?

[jbenam]

So the clock runs well while the Amiga is running? If so, the crystal is fine.

Must be a voltage issue then, looks like it's not keeping the RTC chip powered.

Please check what Chucky suggested

[StompinSteve]

Ok I followed Chucky's recommendations (I think, I hope):

I did not quite understand what was meant with "and the cap that is on the outer end of that block" so I put my multimeter in Continuity mode and went bezerk, touching and testing everything around the RTC chip.

I basically did four sets of tests:

Test 1: Multimeter's black lead on Battery's + and red lead on both sides of the little black component next to the oscillator.
Line colour: red
Result: No continuity on either side of the component
(also reversed the black and red leads but then no beeps from the Multimeter at all).

Test 2: Multimeter's black lead on Battery's + and red lead on other nearby components..
Line colour: yellow (I tested everything there and no yellow line means no continuity).
Result: continuity OK only the sides of the components "touched" by yellow lines.
(reversed the black and red leads but then no beeps from the Multimeter at all)

Test 3: Multimeter's black lead on Battery's + and red lead on all 18 legs of the RTC chip (one by one of course).
Line colour: green (no green line means no continuity)
Result: Continuity OK
I also tested the small greenish component near pin 18 of the chip. Had continuity on both sides.
(also reversed the black and red leads and Multimeter beeps then also)

Test 4: Multimeter's black lead on bottom (towards edge of the PCB) of small black component and red lead on pin 18 of the RTC chip.
Line colour: purple
Result: Continuity OK
(also reversed the black and red leads and Multimeter beeps then also)

[Chucky]

Test 1 that one shold go to plus on battery, from the other side than the purple that is connected to the RTC chip.

and I was stupid. it wasn't to a cap. it was to one of the diodes the cadfile I had did not comntain componentdata just the pads

[StompinSteve]

Originally Posted by Chucky

Test 1 that one shold go to plus on battery, from the other side than the purple that is connected to the RTC chip.

That is what I did didn't I ? I tested "Plus on battery" to "both sides of the little black component (red lines)", even though you told me to only test the "top" side of that black component ("bottom" side = close to the edge of the board there in my photo)".

There is no continuity between the "Battery Plus" and the "top side" of the black component (red line going straight from under the letters "at" towards the "top side" of the black component).

There is continuity between the "bottom side" of the black component and pin 18 of the RTC chip (purple line).

[Chucky]

I had card rotated other wat.

however that end of the resistor you get connection to pin 18 of the RTC chip.
the OTHER end should go to + of battery

[StompinSteve]

:-)

If we call "bottom" side = close to the edge of the board there in my photo
and
"top side" is towards the middle of the board (what you call "the other end").

Then:
the bottom side of the resistor (close to the edge of the board) has connection to pin 18 of the RTC chip
and:
the "other end" (what I call "top side", towards the middle of the board) does NOT have a connection to the battery plus.

I guess a piece of the trace between the battery's + and that resistor is kaput?

The fact that the + of the battery successfully connects to many many places elsewhere on the board indicates the broken trace (or whatever) is closer to the resistor.

Where does the + of the battery connect to something else for the first time?
I see a single trace coming from the Battery's + via, going along the outside of the bottom of the PCB (top side for me = where the battery is) all the way up towards the SIMM slot and then I lose it / have difficulty following it further.

[StompinSteve]

Question: Can't I simply remove the RTC chip (and battery) from the board completely? Will it cause problems or have no effect at all?

If it has no side-effects at all, i'll simply plug in a battery-backed RTC unit in the motherboards clockport and problem solved.

[Chucky]

board works fine wigholut it.. to be honest why even bother. I sync time via network

[StompinSteve]

Ok then off it goes. Gonna be fun without a desoldering-device but i'm a patient man.

Timesyncing over the network is "too modern" for me. I goes against my "original Amiga experience" mantra

It's also the reason why I don't go the 68080 route. I had an A500 and later an A4000/040 back then and that's as far as i'll go

[daxb]

What do you do if programs/scripts use time/date for its tasks?!

[StompinSteve]

Originally Posted by daxb

What do you do if programs/scripts use time/date for its tasks?!

As I wrote, i'll simply plug in a battery-backed RTC unit in the motherboards clock-port.

In my experience, working with Workbench is a nightmare without a working clock. Constantly running into problems with time-stamps being wrong, creation dates in the future and all that jazz.

[StompinSteve]

Talked to Jens Schönfeld about my little problem. He advised me to take the easier route and lift pin#2 of the OKI RTC (select pin), then make a connection with a 10k ohms resistor between pin#18 and that lifted pin. That will silence the chip.

Well, I could not lift pin 2 as those pins are super close to the SIMM slot and each other. I don't have the skills to pull that off. So I pulled something else off: the entire chip.
All fine. System runs stable but has no RTC anymore. All good.

Then I unpacked the package from Jens that came in the mail, happy to see the RTC module. Opened my A1200 and started crying
Turns out, I have a 1D4 motherboard with the clock-port pins on the "other" side...
Found this image of such a board: https://bigbookofamigahardware…4_clo..._darkgreen.jpg
On that same page, there is also an image of a 1D4 with the clock-port pins closer to the outside edge. This is what Jens his module is designed for as it has an L-shape to plugin into the port and the long side of the L go along the Kickstart chips.

Long story short, I can't use his RTC module.
The RTC module from AmigaKit is the same shape as the Individual Computers product so won't work either.

Cannot use this module from Amigastore.eu either as my Indivision AGA MK3 is in the way.
https://amigastore.eu/en/744-a…al-ti...ck-module.html

I must now find one that works with my version of the 1D4 board. No luck so far.

Man I need a drink...