OBERHEIM SYNTH

Anyone happen to know the voltage/amps/current of the perf/x unit's power adapter?

thanks


--- In oberheim@yahoogroups.com, Martin Ator <cyllall@...> wrote:
>
> There's some test points on the PCB near the Intel CPU. +5 and GND. You can 
> check the function of the regulator here and monitor any changes in voltage.
> The PC900 could cause midi problems. According to the datasheet the LED that's 
> inside the PC900 decreases in luminosity by 50% after 5 years of use. You could 
> possibly test the Midi by using Midi thru socket instead of the Midi in(if it 
> has a midi thru socket) Try a sysex dump out and send it back in with the midi 
> in port to test that if it doesn't work properly try the thru. I don't know if 
> the cyclone has a verify sysex function. You should use that and not load 
> directly into memory if poss. You could maybe change the Midi in 220 ohm 
> resistor (R4?)to 150 or 120 ohm.
> 
> 
> 
> 
> 
> ________________________________
> From: sokkerkid10101 <sokkerkid10101@...>
> To: oberheim@yahoogroups.com
> Sent: Sat, 29 January, 2011 9:42:30
> Subject: [oberheim] Re: Oberheim Perf/x Drummer problem
> 
>   
> Read through some other google links
> do you think it could possibly be the photocoupler (pc900)
> I will also start testing the regulator, since that
> is what some have claimed to cause them problems. It's not
> the power supply and all solder points and resistors look good...
> 
> --- In oberheim@yahoogroups.com, "cyllall" <cyllall@> wrote:
> >
> > I'm looking at some pictures of a Cyclone I found online as I don't have any 
> >Perf/x stuff.
> > 
> > Check that all the legs in any socketed chips are actually in the socket. It is 
> >possible when putting a chip in, to bend the legs back on themselves in a "U" 
> >shape and it looks like they are in and they're not.
> > There may be something wrong with your display showing 3 instead of 8.
> > You can check for cracked solder or a short circuit by the display/resistors 
> >and underneath.
> > This could be a power supply problem.
> > You need to check the +5v and GND test points on the board.
> > If you clip a crocodile clip to the regulator(as a heatsink) and it then takes 
> >longer to go funny then it could be the regulator.
> > Make sure your power adapter is the correct voltage and unless it's the same 
> >mah rating as the original(or is the original) it should be a regulated/switched 
> >mode supply, so as not force too much current in.
> > I would take the battery out for now as it could hold corrupted data in the 
> >RAM.
> > Wait a few minutes and do a hard reset.
> > 
> > 
> > 
> > --- In oberheim@yahoogroups.com, "sokkerkid10101" <sokkerkid10101@> wrote:
> > >
> > > narfman96:
> > > No nothing seems to be getting too hot but that seems like a very logical 
> >possibility and would explain why there is a delay for it reverting to a state 
> >of 0 ram, maybe the bad component is dealing with the ram
> > > 
> > > Martin:
> > > The original battery was a DL2032, I tore that out and have in it now a 
> >CR2032. The original ram (8k one)is# made by hyuandai, I replaced it with a 32k 
> >of HM62256LP-10.
> > > 
> > > One thing to note is that when the version displays on startup, it says 3.3, 
> >although the manual says it should be at least 3.8
> > > 
> > > Yes the CPU (and the ROM for that matter) both appear to be in correctly
> > > 
> > > Yes there is only one ram chip
> > > 
> > > And yes I have access to a voltmeter (and one of those displays that show 
> >current and stuff-i know I sound like an idiot, I can't remember the name of 
> >them right now) I am not keen on circuitry however
> > > 
> > > 
> > > Thank you
> > > 
> > > --- In oberheim@yahoogroups.com, "narfman96" <narfman96@> wrote:
> > > >
> > > > This problem sounds like a component is overheating and shutting down. A 
> >capacitor could be leaking to ground. Have a tech look at the power circuit and 
> >then the cpu and the rest of the digital section. Is anything getting warm or 
> >hot? 
> >
> > > > Fran
> > > > --- In oberheim@yahoogroups.com, Martin Ator <cyllall@> wrote:
> > > > >
> > > > > Hi,
> > > > > What type of battery is it? CR2032?
> > > > > What is the part number of the original RAM, is it something like this on 
> >the 
> >
> > > > > end ******-15L
> > > > > Have you identified the CPU, is it in a socket, is there only one RAM 
> >chip, have 
> >
> > > > > you got a voltmeter?
> > > > > 
> > > > > Martin
> > > > > 
> > > > > 
> > > > > 
> > > > > 
> > > > > ________________________________
> > > > > From: sokkerkid10101 <sokkerkid10101@>
> > > > > To: oberheim@yahoogroups.com
> > > > > Sent: Sat, 22 January, 2011 12:17:01
> > > > > Subject: [oberheim] Re: Oberheim Perf/x Drummer problem
> > > > > 
> > > > > 
> > > > > Thank you for the reply and info about the battery
> > > > > 
> > > > > I put a 32k ram chip in there but the problem still persists. However I 
> >believe 
> >
> > > > > the problem is due to something with the RAM since I get the same 
> >messages when 
> >
> > > > > there is no RAM chip in it; except it takes a few moments to occur when 
> >there is 
> >
> > > > > a chip in it. 
> > > > > 
> > > > > 
> > > > > Any other help would be appreciated, I can make a video if needed. Also 
> > > > > considering taking it to a pro...
> > > > > 
> > > > > --- In oberheim@yahoogroups.com, "Steve" <steve@> wrote:
> > > > > >
> > > > > > The battery keeps the data in the RAM alive.  Without it, it would 
> >revert back 
> >
> > > > > >to factory
> > > > > > settings when you shut off the power.  Today we would use Flash memory 
> >for 
> >
> > > > > >this, but battery backed RAM was one of the better options back then.
> > > > > > 
> > > > > > As far as curing what ills your drummer, I can only suggest reseating 
> >anything 
> >
> > > > > >that is socketed, in case oxidation is making a bad connection 
> >somewhere.
> > > > > > 
> > > > > > --> Steve
> > > > > > 
> > > > > > --- In oberheim@yahoogroups.com, "sokkerkid10101" <sokkerkid10101@> 
> >wrote:
> > > > > > >
> > > > > > > Hey all, first of all- hi
> > > > > > > I was running out of options until I found this wonderful group!
> > > > > > > 
> > > > > > > Secondly,
> > > > > > > I just purchased an oberheim drummer off ebay and it started giving 
> >me 
> >
> > > > > >problems immediately. The issue is that, if I let it sit and rest for a 
> >bit, it 
> >
> > > > > >starts up fine and works great, until after about 1-3 minutes when all 
> >of the 
> >
> > > > > >function become inaccessible. AKA it shows "0" for preset, and it is 
> > > > > >unchangeable, as well as all other functions show "oF" and I cannot 
> >change it. 
> >
> > > > > >This will happen immediately if I just switch it from on to off.
> > > > > > > 
> > > > > > > I have it opened up here (got scared that I had destroyed it on one 
> >or two 
> >
> > > > > >occasions while playing with the ram and eprom). I am trying a new 
> >battery but i 
> >
> > > > > >don't have my soldering iron here at school so it is just sitting 
> >between the 
> >
> > > > > >tabs.
> > > > > > > 
> > > > > > > what does the battery do btw?
> > > > > > > 
> > > > > > > And I have a new 32K X 8 ram on its way. 
> > > > > > > 
> > > > > > > Any other suggestions?
> > > > > > > 
> > > > > > > Thank you!
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>