OBERHEIM SYNTH

Oh god I hope not...those were the crappiest solder joints; I am surprised it even turned on. But it did!

--- In oberheim@yahoogroups.com, Martin Ator <cyllall@...> wrote:
>
> Well done. You will be building your own synthesisers next.
> 
> 
> 
> 
> ________________________________
> From: sokkerkid10101 <sokkerkid10101@...>
> To: oberheim@yahoogroups.com
> Sent: Tue, 15 February, 2011 7:29:06
> Subject: [oberheim] Re: Oberheim Perf/x Drummer problem
> 
>   
> Fixed! Replaced voltage regulator
> thanks
> 
> --- In oberheim@yahoogroups.com, "sokkerkid10101" <sokkerkid10101@> wrote:
> >
> > 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!
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > >
> > >
> >
>