Dismantling a Sunpak 544 "potato masher"

<p>I'm trying to dismantle my Sunpak 544 "potato masher" flash in order to add a 1/8" miniplug for syncing it more reliably. I removed the screws under the rotating head, and popped the clips near the top of the handle, but I can't figure out how to separate the front & rear halves at the bottom of the handle. Any suggestions? The last thing I want to do is break it.</p>

<p>Probably the same as a 522, see here:</p>

<p>http://www.photo.net/photography-lighting-equipment-techniques-forum/00XNTn</p>

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<p>Ben, If this is a thyristor (I think it is), I've been told to be very careful what you touch, and that it might carry quite a charge.</p>

<p>Capacitors hold charge, not thyristors. But yes, be careful. All flashes will have a high voltage capacitor.</p>

<p>Sure enough, there are two more screws hidden under the sticker at the butt of the handle around the 1/4-20 mounting hold. The sticker is actually about 1mm thick. There isn't much of a gap between the sticker and the surrounding handle, so I had a hard time prying it off without buggering up the plastic, but I managed. The adhesive was still sticky enough that I didn't have re-glue it; I just pressed it back on when I was done.</p>

<p>Soon, I'll have a write-up on adding the 1/8" miniplug sync port to this flash, complete with photos. The clearance inside that housing is tighter than you might think for such a large flash.</p>

<p>f-ing PN policy on editing previous posts... This is one of the reasons I dropped my paid subscription.</p>

 

<p>As for the capacitor, I made sure I drained it by shorting the leads for several seconds with a 100K ohm resistor (held with insulated pliers). I think it was probably drained already because it hadn't been used in a few days, but I wanted to be sure.</p>

<p>Ben; there use to be NO editing at all; this went on for about almost decade.</p>

<p>Today one can edit for 10 minutes; which works even on dialup.</p>

<p>ie I can do 3 or 4 corrections</p>

<p> There has to be be a some time limit; to reduce the Beavis and Butthead behavior.</p>

<p>ie one can call another an ahole; get them to fire back; then you retract you first strike comment to appear as a total saint.</p>

<p><strong>What time window do YOU want; to NOT call it a: </strong></p>

<p>"XXXX-ing PN policy on editing previous posts.."?;</p>

<p>ie 1, 3, 10 30 minutes; hours; days; years?</p>

 

<p>As far as draining the high voltage 300 to 600 volt DC flash cap; after discharging them with a high resistance resistor; many will rise again in voltage after the resistance is removed. ie loose charge in the dielectric can make the cap rise in its DC voltage seen on its terminals.</p>

<p>With a super giant cap say in laser work; this charge is enough to kill one; thus you leave the cap shorted for safety reasons. With a flash cap on strobe; you just get zapped and thus startled. In many places I have worked; unused high voltage caps are shorted to prevent shocks.</p>

<p>I have seen surplus caps at swap meets be live; sort of weird since they were in a guys junk box for years.</p>

<p>Some Sunpack strobes like my old Sunpack 611 have many leads on the flash cap; ie it is a custom cap with many caps in series; all tapped with leads.</p>

<p>I hope your miniplug is a better one; here I have had many on cellphone and other small gizmos get flakey after used many dozens of time. ie like the temper on the spring contact on the jack is total crap; it it creeps.</p>

<p>In some flashes I have opened up; to get them back together is a total mess. ie the plastic has shrunk and thus to mating parts are a devil to snap back.</p>

<p>Every other forum to which I'm subscribed allows continuous editing of posts, and changing history in the manner you suggested is uncommon enough that I've never seen it. Alternately, I should at least be allowed to edit my post until somebody else replies. Today, I had an edit link, which I clicked, but the timeout must have expired while I was composing, because I wasn't allowed to submit my changes. Very annoying. I also can't stand the odd mix of HTML and plain text between which PN seems to alternate when composing various text fields. Pick a format and stick with it like the rest of the world does.

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For the caps, that's probably good advice. There were multiple terminals coming from the cap in my 544, but two of them were nearly the size of car battery terminals with a pound and a half of solder on each, so I shorted across those. I never did check it with a multimeter (I'd left mine out in the garage and was too lazy to go retrieve it), but I made it through alive.

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I bought my miniplugs from Radio Shack (<a href="http://www.radioshack.com/product/index.jsp?productId=2103452">part number 274-249</a>, $3 for 2 jacks). They seem to work nicely right now, but time will tell. I made this mod because the factory Sunpak sync jack was acting flaky at my last shoot, and my radio triggers already have built-in 1/8" jacks.

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My plastic fit back together just fine once I figured out how each of the boards was supposed to be inserted into the casing. It all kind of fell apart when I opened the case, and I wasn't ready for that, so I wasn't paying close attention to how it was originally assembled.

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<p>Recap: I wrote up a web page with photos describing how to disassemble & reassemble the Sunpak Auto 544, as well as a couple other flashes, so as to add a 1/8" sync jack.</p>

<p>http://www.jedi.com/obiwan/photo/syncjack.html</p>

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