Olympus FL-36 flash head - anyone ever opened one?

[PakkyT]

Rather random question, but I got two non-functional FL-36R flashes from another member here from the Free to good home / karma / pay it forward thread here at Mu-43 thinking I could get one or both working.

Short version I need to get into the flash head part and for the life of me can not figure out how to crack this baby open. There are two screws which I removed, but there does not seem to be any other fasteners and as much as I try to split the two halves apart it seems like there is something else holding them other than cheap plastic clips. This is the part I mean...

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Longer version: One flash turned on and was fully functional except you couldn't actually fire the flash (either with the test button or on the camera through the hotshoe). The other one didn't power up at all and was simply dead. So I speculated that the almost working one had a bad connection within the head so it was not seeing the "FIRE" signal. On the dead one I figured it was the main body circuit board and unlikely that its head was also bad, so I went about swapping the head from the dead unit onto the almost working unit and after MUCH struggle getting it all back together with dropping tiny screws, springs, and plastic pieces over and over and trying to figure out the origami used to assemble these, I finally got it back together. The almost working flash is now fully functional. Yay!

Later playing with just the PCB half of the body of the dead unit and the battery compartment (see upper left in photo above), I put batteries in it and held them in place with the loose battery door and NOW it powers up. So there is hope. But I still have to investigate the bad connection in the head I pulled from the other one and this is where I am stuck because I can not get the damn thing open. So posting here on the off chance someone here disassembled on of these and might know the trick.

 

[Michael Meissner]

I don't know how tech savvy you are, but obviously with flashes the capacitor bank can be deadly if the capacitor still has a charge and the current goes through your body. Even if you think there is no charge in it, be sure to safely discharge it.

Here is a FAQ for working on flashes that I saw several years ago:

• Sam's Flash FAQ

 

[gnb40]

I just found this on an old DPReview thread....

"The two disks at each end of the head probably need to be pried off. Most likely held by double sided tape, but possibly glued on. That will reveal other screws. Be sure to discharge the capacitor housed in cylindrical section at top of the bottom section".

Can't vouch for this. I replaced the tube in one many years ago, took a while to get everything to fit when I was putting it back together. I seem to remember there were a couple of screws in the plastic rim around where the wires come through. Could be wrong on that... it was a FL-36 and many years ago.

Good luck,
Gary

 

[PakkyT]

I don't know how tech savvy you are, but obviously with flashes the capacitor bank can be deadly if the capacitor still has a charge

Pretty savvy as I am an electrical engineer and at one time even worked for a company making X-Ray equipment and had to trouble shoot the 35-50kV generators (ALWAYS kept one hand in my pocket when working on those).

On the one FL-36R I did get working, I did accidentally discharged the cap putting it together (I had powered it up previously in pieces but all connectors plugged in to verify it worked before re-assembling it) when I was plugging one connector. Nice loud POP that scared the crap out of me. ? Fortunately the discharge didn't break anything.

I just found this on an old DPReview thread....

Thanks for that. I did pry at the rubber ends a few times but you know how it is when you start to have to apply more pressure and you are not sure if it just takes more force or if you are prying something that isn't it and you are going to break it. Guess I will just go for it and see. If it breaks, oh well. I will try a hair dryer on it to see if I can soften it up if held by doubled sided tape.

I seem to remember there were a couple of screws in the plastic rim around where the wires come through.

There is a metal piece that goes over the plastic rim and was held on by 5 screws. I took that off and there doesn't appear to be any addition screws there.

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It must be under the rubber piece on either side (one of which houses the button to unlock the head to adjust for tilt.

 

[PakkyT]

OK, double sided tape it was. Blow drier on each side for a minute and I was able to lift off the heavy rubber pieces to uncover 8 more (4 per side) tiny Phillips head screws. BTW, the flash is a mix of 000 Phillips and T5 Torx screws or various lengths and heads in case someone reading this later is looking for a tools required list.

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Flash cap is an 800uF, 350V and when fully charged it is at 300V. I use a simple 10k-ohm resistor wrapped between the leads of my meter to discharge it. This is a nice way to do it because you can watch the voltage drop on the meter and know you are doing it right and when it is safe.

Unfortunately I don't see any obvious broken wires as I was hoping, so got to dig into this further.

 

[gnb40]

I replaced a hot shoe on one of these (years ago, I had switched to full frame, now going back to MFT). While doing it, I checked the wires from the shoe and found one had very high resistance (probably from flexing). You might want to check that.

I'd be interested in knowing how you made out.

Gary

 

[PakkyT]

I checked the wires from the shoe and found one had very high resistance (probably from flexing). You might want to check that.

Thanks but that wasn't it. I tried it on the hot shoe of my E-M1 to be sure it wasn't only a bad test button but neither the test button nor the hot shoe contacts would fire the flash. In fact in the first one I got working I broke one of the hot shoe wire so in addition to the head I swapped the hot shoe from the dead unit. Yesterday I re-soldered the hot shoe at work (I don't have a good soldering iron at home for delicate work). I am able to power up the dead unit now and it acts just like the other one did (since I am using the other one's defective head unit). It powers, charges the cap, read light comes on, all controls work, I can zoom the flash head, etc. But the flash will not fire with the test button. So it is definitely in the head unit since the head acts the same on both otherwise fully operational bodies.

I think I figured out what most of the various connectors go. Most of which have nothing to do with firing the flash but are either switches to tell the flash the position of the head, if the close up panel is out, the AF illuminator & the RC receiver on the front, and the little flash head zoom motor with position potentiometer. I am down to one connector which is the one that powers the capacitor and two of the signals off it, judging by the name on the PCB in the head go to gate signals, one to an SCR (silicone controlled rectifier) and one to an IGBT (insulated gate bipolar transistor). All the wires ohm out correctly (no broken/open wires). Unfortunately I am not sure of what the voltage levels should be in them and which one actually fires the flash. Each one could be the trigger or could be the "quench" to stop the flash. Maybe I will take it into work next week so I can solder tack some test wires onto some spots to try and get some measurements with things powered up.

 

[ouldsmobile]

@PakkyT if you can't get the second one working and are just going to throw it away, I have a FL36r that has a broken lock ring that I wouldn't mind replacing.

 

[PakkyT]

@PakkyT if you can't get the second one working and are just going to throw it away, I have a FL36r that has a broken lock ring that I wouldn't mind replacing.

No problem. It is currently off and put to the side while I work on the rest of it. The black wire (as mentioned above) is freshly soldered back on after I broke it off. So if I give up I can send just the hot shoe part if that is all you need...

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While you can replace just the lock ring, it is actually easier to replace the whole foot as shown above (you have to get it to this level anyway to get to the lock ring). If you disassemble further, removing that little green PCB, under is a bunch of little springs and little metal bits that act as the shoe pins. It is very fiddly to get it all back together without dropping the little springs and pins while trying to line everything up when putting it back together.

 

[ouldsmobile]

No problem. It is currently off and put to the side while I work on the rest of it. The black wire (as mentioned above) is freshly soldered back on after I broke it off. So if I give up I can send just the hot shoe part if that is all you need...

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While you can replace just the lock ring, it is actually easier to replace the whole foot as shown above (you have to get it to this level anyway to get to the lock ring). If you disassemble further, removing that little green PCB, under is a bunch of little springs and little metal bits that act as the shoe pins. It is very fiddly to get it all back together without dropping the little springs and pins while trying to line everything up when putting it back together.

Sweet, thanks! Yep, all I need is the shoe part. PM me if you decide to get rid of it, no worries though if you don't. I will obviously pay for shipping etc.