Fixing an old electronic organ
 

Hello electronics experts

I hoped someone could help a novice with this repair. I recently bought an
organ (70's technology!) but one PCB has been physically damaged. I have
some broken devices on this board (as well as some broken tracks). They are
17-pin SIP resistor networks (I think) and the question is whether I would
be able to find out whether they are just resistors and if so get a modern
replacement. I can't look it up anywhere as there's no technical info
around any more as the thing is so damn old! Any ideas?

Thanks in advance
Jason.
--

Jason Welch wrote:

Hello electronics experts

I hoped someone could help a novice with this repair. I recently bought
an
organ (70's technology!) but one PCB has been physically damaged. I have
some broken devices on this board (as well as some broken tracks). They
are 17-pin SIP resistor networks (I think) and the question is whether I
would be able to find out whether they are just resistors and if so get a
modern
replacement. I can't look it up anywhere as there's no technical info
around any more as the thing is so damn old! Any ideas?

Thanks in advance
Jason.
--

Jason,

I fear that the SIP's may be more than just resistors. They may be RC
phasing networks (Resistors and capacitors). Dimensions please? Any
numbers, letters, or other identifiers at all? Are they really little
circuit boards with little resistors and caps, and possibly transistors?
Are the pins "linearly regular" in spacing, or irregular? Irregular
suggests something other than resistors -- maybe. Since you have broken
ones, take one apart if big enough, and the coatings can be chipped or
peeled off. I'm hazarding a guess you've got something more than
resistors. Sorry.

Thanks, Steve

"Jason Welch" wrote in message
...
Hello electronics experts

I hoped someone could help a novice with this repair. I recently bought
an
organ (70's technology!) but one PCB has been physically damaged. I have
some broken devices on this board (as well as some broken tracks). They
are
17-pin SIP resistor networks (I think) and the question is whether I would
be able to find out whether they are just resistors and if so get a modern
replacement. I can't look it up anywhere as there's no technical info
around any more as the thing is so damn old! Any ideas?

Thanks in advance
Jason.
--





If it's 17 pin then it is likely 16 resistors and one common and will be
used as a pull-up or pull-down (most likely the former) on digital inputs.
The type number on the body should give you an idea of value - something
like 473 might indicate 47K per resistor, whereas 822 would be 8.2K.


--

Woody

Woody wrote:
"Jason Welch" wrote in message
...

Hello electronics experts

I hoped someone could help a novice with this repair. I recently bought

an

organ (70's technology!) but one PCB has been physically damaged. I have
some broken devices on this board (as well as some broken tracks). They

are

17-pin SIP resistor networks (I think) and the question is whether I would
be able to find out whether they are just resistors and if so get a modern
replacement. I can't look it up anywhere as there's no technical info
around any more as the thing is so damn old! Any ideas?

Thanks in advance
Jason.
--






If it's 17 pin then it is likely 16 resistors and one common and will be
used as a pull-up or pull-down (most likely the former) on digital inputs.
The type number on the body should give you an idea of value - something
like 473 might indicate 47K per resistor, whereas 822 would be 8.2K.


They might also be some kind of hybrid circutry. A picture will indeed help.

/John
remove 2 x nspam and replace pillow with hovedpuden in e-mail if you
want to reply direct to me.

Steve wrote in message ...
Jason Welch wrote:

Hello electronics experts

I hoped someone could help a novice with this repair. I recently bought
an
organ (70's technology!) but one PCB has been physically damaged. I have
some broken devices on this board (as well as some broken tracks). They
are 17-pin SIP resistor networks (I think) and the question is whether I
would be able to find out whether they are just resistors and if so get a
modern
replacement. I can't look it up anywhere as there's no technical info
around any more as the thing is so damn old! Any ideas?

Thanks in advance
Jason.
--

Jason,

I fear that the SIP's may be more than just resistors. They may be RC
phasing networks (Resistors and capacitors). Dimensions please? Any
numbers, letters, or other identifiers at all? Are they really little
circuit boards with little resistors and caps, and possibly transistors?
Are the pins "linearly regular" in spacing, or irregular? Irregular
suggests something other than resistors -- maybe. Since you have broken
ones, take one apart if big enough, and the coatings can be chipped or
peeled off. I'm hazarding a guess you've got something more than
resistors. Sorry.

Thanks, Steve

It would help if the poster gave us a brand name for the organ, and
maybe a model number, and anything else that is marked on the organ to
give us a clue. It would also help to have a photo of the broken unit
and one of a good unit to see if they are the same component.
Nothing like that was given, so it is almost an impossible task to
make coherent suggestions.

H. R. (Bob) Hofmann

Steve wrote in message ...
Jason Welch wrote:

Hello electronics experts

I hoped someone could help a novice with this repair. I recently bought
an
organ (70's technology!) but one PCB has been physically damaged. I have
some broken devices on this board (as well as some broken tracks). They
are 17-pin SIP resistor networks (I think) and the question is whether I
would be able to find out whether they are just resistors and if so get a
modern
replacement. I can't look it up anywhere as there's no technical info
around any more as the thing is so damn old! Any ideas?

Thanks in advance
Jason.
--

Jason,

I fear that the SIP's may be more than just resistors. They may be RC
phasing networks (Resistors and capacitors). Dimensions please? Any
numbers, letters, or other identifiers at all? Are they really little
circuit boards with little resistors and caps, and possibly transistors?
Are the pins "linearly regular" in spacing, or irregular? Irregular
suggests something other than resistors -- maybe. Since you have broken
ones, take one apart if big enough, and the coatings can be chipped or
peeled off. I'm hazarding a guess you've got something more than
resistors. Sorry.

Thanks, Steve

It would help if the poster gave us a brand name for the organ, and
maybe a model number, and anything else that is marked on the organ to
give us a clue. It would also help to have a photo of the broken unit
and one of a good unit to see if they are the same component.
Nothing like that was given, so it is almost an impossible task to
make coherent suggestions.

H. R. (Bob) Hofmann

On Sun, 22 Aug 2004 20:10:41 +0200, John Damm Sørensen
wrote:

Woody wrote:
"Jason Welch" wrote in message
...

Hello electronics experts

I hoped someone could help a novice with this repair. I recently bought

an

organ (70's technology!) but one PCB has been physically damaged. I have
some broken devices on this board (as well as some broken tracks). They

are

17-pin SIP resistor networks (I think) and the question is whether I would
be able to find out whether they are just resistors and if so get a modern
replacement. I can't look it up anywhere as there's no technical info
around any more as the thing is so damn old! Any ideas?

Thanks in advance
Jason.
--






If it's 17 pin then it is likely 16 resistors and one common and will be
used as a pull-up or pull-down (most likely the former) on digital inputs.
The type number on the body should give you an idea of value - something
like 473 might indicate 47K per resistor, whereas 822 would be 8.2K.


They might also be some kind of hybrid circutry. A picture will indeed help.



They may also be an early IC which appeared on the circuit diagram as a
single transistor with many emitters. I would have to look this up as it
is long ago...


--
ajb