I'm looking for a bit of advice or better yet a schematic for a Metrix 803B oscilloscope.
The 40MHz animal here...
.. I picked one up for very little on ebay, and it looks quite a useful thing to have around.
The listing stated that it was dead, but in clean condition, so I took a gamble that it might be something simple.... needless to say it wasn't the fuse or the mains switch, and the next logical step is to check the power supply.
Naturally I can find no schematic on line for it, so before I start to reverse engineer the thing, I wondered if anybody else had a schematic, or access to another 803B to compare.
Everything looks clean and there are no obvious crispy bits or popped or bulging caps. When I power on, the mains gets from the power jack board, through the mains switch and over to the PSU board, and appears at the input side of the switch mode supply. Thats as far as I have probed so far, other things keep getting higher priority.
I dont appear to get any audible high frequency squeak from the switch mode transformer or static on the tube, at start up suggesting it might be fairly simple to track down, but before I actually start to get my hands dirty I thought I would ask around in case the fault is a well known issue that someone here has enountered before.
An incomplete set of pictures of the innards of the poor beast complete with optional dust are available here.... and yes, I know that the fuse is missing in some of those pictues, I had popped it out to test it. I did remember to re-fit it.
The 40MHz animal here...
.. I picked one up for very little on ebay, and it looks quite a useful thing to have around.
The listing stated that it was dead, but in clean condition, so I took a gamble that it might be something simple.... needless to say it wasn't the fuse or the mains switch, and the next logical step is to check the power supply.
Naturally I can find no schematic on line for it, so before I start to reverse engineer the thing, I wondered if anybody else had a schematic, or access to another 803B to compare.
Everything looks clean and there are no obvious crispy bits or popped or bulging caps. When I power on, the mains gets from the power jack board, through the mains switch and over to the PSU board, and appears at the input side of the switch mode supply. Thats as far as I have probed so far, other things keep getting higher priority.
I dont appear to get any audible high frequency squeak from the switch mode transformer or static on the tube, at start up suggesting it might be fairly simple to track down, but before I actually start to get my hands dirty I thought I would ask around in case the fault is a well known issue that someone here has enountered before.
An incomplete set of pictures of the innards of the poor beast complete with optional dust are available here.... and yes, I know that the fuse is missing in some of those pictues, I had popped it out to test it. I did remember to re-fit it.
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