Hi Milan, This is always going to be difficult if electronics isn't your speciality, so do not get too hung up about it. I find this mixture art and science is not a good combination. I am poor musician but pretty good at electronics, I suspect it is the other way around for you. Not sure you can be good at both! Anyway. I don't want to be rude or disrespectful to the repairer, but this falls way short of the standards I would expect a board to be return to me in (plus it still has a fault). What I can tell you is that the diodes both appear to be correctly inserted from the topside, although I can't vouch for the bottom. I am not sure what the red goo is under the battery, but I suspect this is some kind of insulation? Perhaps we have a very slow leak to ground through this material which is causing the battery to drain. I personally would have mounted the battery 90 degrees to the current position with the body slightly 'floating' above the print surface (negative facing forward). One big observation is that it looks like the SRAM IC is in back to front! There is usually a dot marking pin 1 of the device. This seems to be where pin 10 is if you look carefully (this is the chip next to the orange connector). Could you take a mega close up picture of this device so we can have a good look at it. It must admit if this was the case then the print on top of the chip is upside down and the patch memory wouldn't work. But that sure as hell looks like the pin 1 dot to me!! If all else fails send me a private message as I may be able to take a look at the board for you and try and salvage something!! Cheers, Andy From: PolySix@yahoogroups.com [mailto:PolySix@yahoogroups.com] On Behalf Of mekonin Sent: 18 March 2009 09:55 To: PolySix@yahoogroups.com Subject: [PolySix] Re: Having problems after battery replacement Hello guys, sorry for the late response... First of all, I forgot to mention that I know almost nothing about electronics and schematics, and I also need to learn how to use unimers properly. I gave my best to decipher the schemes but I think the best way is for you to look at the pictures of the board here: http://img17.imageshack.us/img17/2954/img0020uwi.jpg http://img5.imageshack.us/img5/5016/img0021c.jpg I can tell that C40 has been removed and that R91 has been replaced but I could not find D15 (I presume that's the one right under R91). Cheers, Milan --- In PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> , "Chromatest J. Pantsmaker" <chromatest@...> wrote: > > Maybe a bent lead on the ram, shorting itself? > > I agree with Andy. The guy didn't fix it right. > > On Thu, Mar 5, 2009 at 7:03 AM, Andrew Jury <andy@...> wrote: > > 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%40yahoogroups.com> [mailto:PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> ] On Behalf Of > > mekonin > > Sent: 05 March 2009 08:44 > > To: PolySix@yahoogroups.com <mailto:PolySix%40yahoogroups.com> > > Subject: [PolySix] Having problems after battery replacement > > - Show quoted text - > > > > > > 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] > > - Show quoted text - > > > > > > ------------------------------------ > > > > PolySix "Digiest" Page: http://www.acc.umu.se/~amber/Poly6Yahoo! Groups Links > > > > > > > > > > > > -- > .sig > -Chromatest J. Pantsmaker > http://www.chromatest.net > [Non-text portions of this message have been removed]
Message
RE: [PolySix] Re: Having problems after battery replacement
2009-03-18 by Andrew Jury