Gould OS1000 B

Hi

I have a OS1000B oscilloscope with a strange fault ...

I was using it recently and suddenly there was smell of resistor burning up ?
I found the Ressy R632 (It was well cooked )

I cannot find a OS1000B schematic so I used a OS1000A !
Q.. are they the same inside ?

Q.. I have looked at the parts list for the OS1000A and it states R632 is 47K 0.5w ... is this the correct value ?
also found C613 stated in the parts list as 1UF 160v .. (E) it is not a Electrolytic ! what type of cap is it ?

Q.. any ideas .. why R632 burnt up ..I cannot find any short circuits ?


if I disconnect PCB pin 34 R632 does not burn .. poss CRT unwell ??

any ideas ?

Thankyou in advance for all your help

Coot said:

I cannot find a OS1000B schematic so I used a OS1000A !
Q.. are they the same inside ?

Click to expand...

Maybe, maybe not. Can you upload some pictures so people know what you are talking about?

Coot said:

Q.. I have looked at the parts list for the OS1000A and it states R632 is 47K 0.5w ... is this the correct value ?
also found C613 stated in the parts list as 1UF 160v .. (E) it is not a Electrolytic ! what type of cap is it ?

Click to expand...

Probably ceramic capacitor, Plastic film capacitor or similar, they are not electrolytic capacitors and have no + or - pins

Coot said:

Q.. any ideas .. why R632 burnt up ..I cannot find any short circuits ?

Click to expand...

Might be anything.. still we don't know what it looks like inside your device.