Philips PM 3214 Oscilloscope Repair. Part 4.

[@Livebirdboxcatterall]

Just watched all 4 videos in the scope repair series again. A great job you did on this and we would all love to see you back on youtube.

[@campbellmorrison8540]

This is the most thorough work through of an oscilloscope I've ever seen, absolutely brilliant thank you.

[@GregorOttmann]

That blue finish looks absolutely stunning. This video series was very rewarding to watch and I hope you'll repair something else soon. :)

[@billtanguay8905]

Great and fantastic job creating a second life for the scope. I have the exact model and my trigger polarity switch failed yesterday because the same plastic peg cracked and loosened on the shaft. I have spent almost a day trying to re-assemble the switch, to no avail. Usually components have to have a reasonable assembly sequence, but this switch - a very clever and inexpensive snap-action design - has out-smarted me in holding it together to re-insert it into the switch housing. At this point I am considering a work-around, not exactly pretty. Kudos to you for reassembling your switch. Now I see that the other few switches have the capability to fail soon in the same manner. Too bad since my scope is entirely functional, even though a little old!

[@rockradio928]

An absolute pleasure to watch you restore this old scope. The presentation was so refreshing and clear. Thank you.

[@mrkattm]

Wow, Fantastic video, I am a degreed engineer and it is sad to say that I have zero troubleshooting abilities, although with every step you took I understood what and why you were doing it. Any how, you have a "good way" about you so please keep it up. I look forward to your next video.

[@Cordiaturbo]

Thanks for sharing. I've just bought a faulty PM3265e to attempt a repair and restoration.

[@johncunningham5435]

Superb job on the repairs; love the new finish, looks like a new scope. " Excellent demonstration "

[@GadgetUK164]

Great job! Looking and working sweet!

[@ovalwingnut]

FAN-TAS-TICK! 25mhz never looked so good. It's a keeper (love the custom blue. Why? Cause nobody else will have it:). Thanks so much for the ride-along.

[@standishgeezer]

Fabulous job. I watched all 4 videos; totally absorbing. Thanks

[@PaulHigginbothamSr]

Most excellent video. have you considered another on this scope, for the heatsinks for the blistering hot transistors, and perhaps other components?

[@charlessmyth]

The original finish is called NEXTEL which is not a durable finish. There is a BNC socket packaged in a nylon bushing, which may have been the proper fit for the rear chassis holes.

[@fredyearian4968]

The larger holes were likely for the BNC connectors that are chassis isolation type which have a larger mounting diameter.

[@JoulesperCoulomb]

You are probably right. I remembered such connectors not long after I put this video together. It also makes the instructions to connect the screen of the connecting leads at both ends seem more sensible. I might change the connectors one day, if I can be bothered.

[@TheAndersenman]

Beautiful device, and great documentation. Wonderful work of investigation, watching you was captivating, thank you very much! Oh, and I just bought one on ebay, used, from private; hopefully it will be in a state as good as, or even better than, yours.

[@TheAndersenman]

So it finally arrived! And it's working. It has a problem though. After about 5 minutes of operation, the beam alignment goes towards +x, and also the brightness reduces significantly. It also appears to spread in the x direction. Would you have any pointers for me before I start opening the thing and blast everything with contact cleaner? Oh, and it's one of the older models where the PM3214 manual actually applies, as opposed to the PM3217 one.

[@TheAndersenman]

And it just died in my arms tonight, as the song goes. It seems that for me it was, in fact, the power supply. When I ran it open for an amount of time, a faint fizzling noise was audible from the rear, from the power supply board, coinciding with the trace getting more and more irregularly dotted. It then stopped, and the power LED as well as the trace went out. A multimeter check revealed that although the raw 27 V were still arriving at the board, none of the other voltages were coming out. I suspect the Base Transformer, part T201, to be the culprit: The noise changed tone lightly when I pushed down on it. I'm looking forward to an adventure of verifying or overturning my suspicion and hunting for parts to get it working again. I shall hope that it's actually one of the surrounding parts which failed, I dread to think of having to find a suitable inductor ...?

[@TheAndersenman]

And once again, news. I wonder what's actually broken, because I have no reference for the resistances for the transformer windings. All the other components around the board, at least those I could check with a DMM, seem to be fine. Only thing I noticed was the two power transistors driving the primaries of T201 are getting very hot even with no load at all, but I can't figure out what's the cause, or if it's intended and the fault lies somewhere else ...

[@kennethdegruchy5503]

Yes I bought one on Ebay about 8 years ago and I like this scope very much but in the last few years it has become unusable because the scope gradually lost brightness control to the point where the brightness control can no longer control trace brightness and the beam is always fully turned on regardless of the position of the brightness control. I will not use the scope under these conditions because the CRT phosphor would be burned which would be a shame for a tube that looked absolutely great before this problem developed very slowly over many months. Little by little I was loosing range on the brightness control not being able to cut off the beam even when turned fully counter clockwise and from there it continued to become brighter and brighter until now the beam is not controlled any longer. I do not see any retrace lines so I assume the horizontal sweep gating circuit for cutting off the beam at retrace time is still working which tells me the tube itself has not lost control grid functionality. Still pondering this one as I would like to get this PM3214 working again.

[@DarthNinjaCode]

NIce video as always. I liked the talking osciloscope :)

[@nando_br]

Very nice work! Congratulations!

[@SpringDivers]

Excellent series. Thanks much.

[@skinnymalink72]

Inspiring series of videos. I just picked up a very similar 3262 which could also do with some case-modding. Do you know whether it is possible to set this scope (or the 3262) into XY mode?

[@JoulesperCoulomb]

+Phelim Burgess I don't know about the PM3262, but the PM3214 can be used in X-Y mode by pressing the X DEFL button; then X deflection is controlled by whatever would otherwise have been selected as the trigger source.

[@garrywilliams3548]

Question for you Joules, how does the delay knob stay on, has it got a grub screw inside or such ?. damn thing falls of on my 3217.

[@garrywilliams3548]

+Garry Williams Answered that myself, you have to take the end plug of to find a screw in it. !

[@parjoleanu1]

Great job sir. I am currently in the process of restoring two PM3264. Until now I had no luck in finding the manual so I had to do it by instinct mainly. Even if the two models are very different I got some general lines that I can follow. Do you know where I can find the manual for the PM3264 or if you have one is it possible to send it to me please?

[@JoulesperCoulomb]

+parjoleanu1 I have never worked on a PM3264 or related model. The service manual for the PM3262 seems to be fairly easy to find online and so far as I can find out, that's the two channel version of the PM3264 and so that document ought to be useful to you.

[@parjoleanu1]

Not to be offensive .....but you try to find it online :)) don't you think I tried that?

[@JoulesperCoulomb]

+parjoleanu1 It only took me a couple of minutes to find the PM3262 manual. I've placed a copy at the following URL (I'll probably only leave it there for a few days): zx.zigg.net/resources/pm3262.zip

[@marco56702]

outstanding work!

[@paulmorrison1821]

Thanks for all the time you spent making such a brilliant video ! I have a PM3311 storage scope which I am trying to fix but have come to a dead end because I can't find a replacement for an I C. It's labeled OQ0017 -wonder if you spotted any IC labeled with OQ---- any where in that scope or anywhere else? Again really great video !

[@JoulesperCoulomb]

I don't think the PM3214 has this IC. I believe the only DIP devices in it are some 74 series logic and some transistor arrays. Assuming you have correctly determined it is faulty, I'd imagine your only options are to find a replacement from another piece of equipment or old stock or to re-create its functions using modern components, perhaps on a small board that can plug-in in place of the original IC.

[@paulmorrison1821]

Yes the fault is on the final X amp board and the IC and a transistor are cooked. I have been thinking along the lines you suggested and will watch out for a little while longer to see if I can pick up another junked PM scope. Just strange I can't find any mention or trace of IC's like OQ0012, OQ0017 and so on, anywhere on the web or indeed from Philips themselves. Anyhow as I say, I really appreciate you putting all your time into making those great UTube videos and your time replying here PaulM

[@MrMac5150]

This looks great.

[@fictionhouse]

Good job!

[@pa4tim]

Nice job and well made videos.

[@KX36]

Since this is more like a 3217 than a 3214 in some ways, I wonder how much work it would be to get 50MHz bandwidth out of it..

[@JoulesperCoulomb]

+KX36 I expect it'd be possible, but probably not worth the bother. If I remember rightly, the 3217 has a completely different vertical amplifier, mounted at the rear rather than on the main PCB.

[@KX36]

That's fair enough. My 1982 vintage PM3217 looks very similar to your 3214. There are 4 PCBs, a power supply identical to yours, an input attenuator board which you've already established yours looks more like the one in the 3217 manual than the 3214 one, the main board which includes the main vertical amplifier and the final amplifier board which sits in the CRT cavity. The final amplifier board has 2 trimmer inductors, 2 trimmer capacitors and 2 trimmer resistors to trim for optimal square wave response. The main board is identical except yours seems to have this final amplifier on the main board right at the back between the CRT and a DIP IC package whereas mine is unpopulated in that area and instead has wires from the main board to the final amplifier board. I don't think mine has what you described as the delay line in it, the chassis is referenced to protective earth and the colour scheme of the front panel is slightly different.

[@GaRbAllZ]

VERY NICE!