Hi Milan,
You should take the board back and tell him he hasn't fixed it properly! ;-)
Seriously, it does sound like there is an excessive load across the
terminals of the battery. Before you do anything else then please make sure
that R91 and C40 have been moved from circuit. D15 should not have been
touched and the new diode (should be a 1N4148 or similar) is soldered in
place of R40 with the anode facing toward the anode of D15. If the new diode
is connected in reverse then the 5V rail will be connected to the battery
whilst the Polysix is switched on! (and also the battery will never power
pin 18 of the SRAM, if it is not destroyed already!).
If all the above look right connect an ohm meter across the battery
terminals making sure the Polysix is disconnected from the mains and the
cell is also removed. What resistance do you get? If it is below 1K ohm then
start pulling the SRAM and re-measuring. IC25 and C36 are also candidates
for failure as they are directly connected to the battery whilst the power
is off.
Let us know what you find.
Cheers,
Andy
From:
PolySix@yahoogroups.com [mailto:
PolySix@yahoogroups.com] On Behalf Of
mekonin
Sent: 05 March 2009 08:44
To:
PolySix@yahoogroups.comSubject: [PolySix] Having problems after battery replacement
Hello good people from polysix support group.
I have one pretty annoying problem with my beloved polysix and I was hoping
if you could help me.
I got it back from repair few weeks ago.
I had the notorious battery problem, and the tech guy fixed almost
everything except one thing.
He replaced the chip which I think is controling the memory, and it is
draining too much power.
We measured almost 30mA, which he says is way too much.
So instantly, when I put the fresh Lithium battery, the voltage goes from
3.3V (or something) to 2.8V, and it takes a few days for the battery to be
completely depleted (the synth is off all the time).
He is 99% sure it is that chip that is causing the problem,
and he suggests me that I find an original one, because he was unable to.
The chip is the replacement for TC-5514, it's 2114 I think.
I have checked if D15 diode is facing the right way, if it's not then the
battery would be routed to ground with 100 ohm which is something about
30mA..
But it's facing the right way.
I looked at the datasheet for the original TC5514 memory chip and it says it
needs up to 180mA in operating and 10mA in standby. The 2114 also uses 10mA
in standby but 100mA in operating mode, so it's a newer and more efficient
chip. It doesn't make sense that it's this chip that's making the problem.
Thanks in advance guys.
Cheers,
Milan
[Non-text portions of this message have been removed]