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2014-10-01 by Florian Anwander
Hello, A buddy of mine has an OB-Xa (quite late version I think Rev6 or 7), which does not boot. It hangs in the boot sequence before doing the voice test and shows two LEDs at the program buttons (I think it is B-5 - I don't have access to the synth at the moment). Is there a list with the meaning of the LED error codes? (assuming that this _is_ an error code). Best regards Florian -- http://fa.utfs.org/
2014-10-01 by 65 Lotus
I don't know of any error codes, sounds to me like it's just hung during the boot sequence. Step one is to check the power supply voltages. The rectifier in the OBXa is notorious for failure. If all's well, then clean and re-seat all the connector cables and pins. If that doesn't work, re-seat all plug-in chips. Still no good, then it's bigger problems. ----- Original Message ----- From: "Florian Anwander fanwander@... [oberheim]" <oberheim@yahoogroups.com>
To: <oberheim@yahoogroups.com> Sent: Wednesday, October 01, 2014 8:48 AM Subject: [oberheim] OB-Xa LED error code at boot time? > Hello, > > > A buddy of mine has an OB-Xa (quite late version I think Rev6 or 7), > which does not boot. It hangs in the boot sequence before doing the > voice test and shows two LEDs at the program buttons (I think it is B-5 > - I don't have access to the synth at the moment). > > > Is there a list with the meaning of the LED error codes? (assuming that > this _is_ an error code). > > > Best regards > Florian > -- > http://fa.utfs.org/ > > > > > ------------------------------------ > Posted by: Florian Anwander <fanwander@...> > ------------------------------------ > > > ------------------------------------ > > Yahoo Groups Links > > >
2014-10-01 by Florian Anwander
Thanks for the reply. We know these topics (I renovated a Xa completely once). The powersupply has been already remade two years ago and as far as I know he did a quite good job at cleaning the connectors at the same time. IC sockets and trimmers still are the old ones. Also the powersupply for the 4051s on one of the control boards is still the old one. Nevertheless our question is: exists a document, that says something about the LEDs states while the boot up. Florian
On 01.10.14 19:03 , '65 Lotus' Lotus@... [oberheim] wrote: > I don't know of any error codes, sounds to me like it's just hung during > the > boot sequence. > > Step one is to check the power supply voltages. The rectifier in the > OBXa is > notorious for failure. > > If all's well, then clean and re-seat all the connector cables and pins. If > that doesn't work, re-seat all plug-in chips. > > Still no good, then it's bigger problems.
2014-10-03 by synthparts@...
2014-10-03 by Bob Grieb
I helped a friend fix his Xa. We found a bad 2114 RAM chip, and
also a chip on the lower board that was shorting one of the data bus pinsto gnd, and bringing the whole system down. We had to cut traces to
isolate which chip it was, since that one bit went to a number of
chips, and none of them were socketed, and also the cable between
the bds was soldered at both ends. Hate doing that, but we did it
discretely and got things going again.
Bob From: "synthparts@yahoo.com [oberheim]" <oberheim@yahoogroups.com>
To: oberheim@yahoogroups.com
Sent: Friday, October 3, 2014 1:07 AM
Subject: Re: [oberheim] OB-Xa LED error code at boot time?
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The OB-Xa doesn't have any error reporting ability other than blinking the voices which can't tune during the auto-tune routine. Possibly bad CMOS, ROMs, RAM, or Z80. I've seen failures in all of those on Xas.
Doug synthparts.com