Hi all - Yesterday I pulled my old Philips PM 3240 out of its 9-year hibernation to do some fault finding on my dac.
Unfortunately the scope wouldn't turn on. I see the red light come on, the display light coming up, but then it shuts down again after 0.5sec. From thereon, it goes on/off/on/off indefinitely.
Any ideas how to fix? It seems the unit is still revivable but not sure how (cap?)
Unfortunately the scope wouldn't turn on. I see the red light come on, the display light coming up, but then it shuts down again after 0.5sec. From thereon, it goes on/off/on/off indefinitely.
Any ideas how to fix? It seems the unit is still revivable but not sure how (cap?)
I have witnessed a miraculous resurrection of the scope yesterday! I worked without any problems for about 1 hour and then without any further symptoms completely went off….
I checked the fuse (ok), probably a psu issue. Since I’ve never worked on a scope (and since last time I worked on diyaudio was a decade ago and my knowledge is a bit rusty), looking for some pointers on troubleshooting the scope….
I checked the fuse (ok), probably a psu issue. Since I’ve never worked on a scope (and since last time I worked on diyaudio was a decade ago and my knowledge is a bit rusty), looking for some pointers on troubleshooting the scope….
My first thought is an issue with old caps in the SMPS. After years in storage there may have been deterioration that 'improves' after use. Temperature may play a part as well.
The board layouts show what seem to be axial caps in many locations and these Philips parts are sometimes prone to issues. No easy answers I'm afraid but it would make an interesting restoration project if done with care.
The board layouts show what seem to be axial caps in many locations and these Philips parts are sometimes prone to issues. No easy answers I'm afraid but it would make an interesting restoration project if done with care.
Hi,
my PM3267 released the blue magic smoke just on first switch-on.
Reason was the notoriously infameous X2-Cap, equiv. to C1804.
Unfortunately with the PM3267 the whole SMPS was cast, so I simply couldn´t repair.
Fortunately though,as it was designed as a ´mobile´ device it featured a dc battery input which I feed from a external 12V dc SMPS till then.
jauu
Calvin
my PM3267 released the blue magic smoke just on first switch-on.
Reason was the notoriously infameous X2-Cap, equiv. to C1804.
Unfortunately with the PM3267 the whole SMPS was cast, so I simply couldn´t repair.
Fortunately though,as it was designed as a ´mobile´ device it featured a dc battery input which I feed from a external 12V dc SMPS till then.
jauu
Calvin