PM3267 oscilloscope

[ppppenguin]

At the Broadcast Engineering Museum we've been given a Phlips PM3267 'scope. Looks like a decent and useful 100MHz instrument. I'm a Tektronix man and have little experience of Philips but have heard that they are good.

A colleague switched it on. Panel lights appeared followed by magic smoke and the swear word "Rifas". Manuals readily available online. PSU circuit attached. It's Philips' own design of switchmode. I have little experience of this kind of PSU so any pointers before I get out the isolating transformer and start probing?

I also brought home a Tek 2465 which probably needs a hybrid and a Tek 1751A waveform and vector monitor which has an obscure fault. Hours of fun.

[ppppenguin]

I'm being daft. I didn't notice that the switchmode is fed by 24V from a double wound mains transformer. Hence no need to keep hands away from rectified mains. Still plenty that can bite, including a 1500V supply that probably supply enough current to hurt.

[Mike Watterson]

I'm being daft. I didn't notice that the switchmode is fed by 24V from a double wound mains transformer. Hence no need to keep hands away from rectified mains. Still plenty that can bite, including a 1500V supply that probably supply enough current to hurt.

I looked at a Philips scope with an exploded Rifa and blown thermal fuse on the transformer. A bridge rectifier that fed the SMPSU had melted the solder and fallen out! The transformer was OK.

At that point (at a friend's house) I said, "unless you are giving it free to me I give up".