Problem With Yongnuo Wireless Controller

[Doug B]

I have just bought a Yongnuo RF-602 Wireless Controller for my Pentax K200D on Ebay. When it arrived I eagerly connected the receiver to an old Starblitz 250BAZ I had laying around. This flash works fine on the hot shoe of the K200D. I mounted the transmitter on the camera hot shoe and fired the camera. The flash flashed. Tried again - nothing. Tried another old flash (Achiever 630AF) - nothing. The lights on both the TX and RX acted as they should as per the manual. Tried using the controller as a shutter release and although the lights acted correctly and a half press activated the auto focus it would not trigger the shutter. After a lot of tests I contacted the seller who sent me FOC another receiver unit. This time I tried it as a shutter release first and it worked just fine. Tried it as a trigger with the Achiever - nothing. Plugged it back in as a shutter release and this time it wouldn't work. All this points to a fault in the receivers caused by the flash units. Does anyone know if these older type flashes operate differently to the more modern ones? I think these flashes are triggered by a circuit being completed. Do more modern flashes operate like that or are they sent a seperate electrical charge to activate them? I opened up one of the RX units and nothing looked wrong with the wires or circuit board. Can anyone shed some light on whether I might be able to save the Controller or should I just chuck it in the bin? It's not the batteries cause I bought new ones. Any suggestions appreciated.
Doug

[jev]

There are a couple of things you can check:
- first, trigger voltage on the flashguns should most probably < 6 Volts (I can't find a spec from this so that's just a guess). If so, the receiver's hotshoe control logic may have died. Check voltage levels here or even better, find a multimeter and measure it.
- trigger voltages on flashguns sometimes use a negative polarity (plus and minus reversed). If this is the case with any of these two, chances are you fried the receiver's hotshoe control logic.
- don't know which type you bought (there are many RF-602 receivers from Yongnuo) - are there any extra pins in the hotshoe? If so, can they have been short-circuited by the flashgun?

[StanW]

Yes, be very wary of older flash units on digital cameras. Trigger voltage is the usual problem.

[MarkChap]

trigger voltage of the flash was the first thing I thought of,

The 250BAZ should be ok though at about 6-7 volts, mine measures 6.5v

[Doug B]

Hi Chaps. Thanks for the replies. I have just measured the trigger voltage for both flashes. They are both centre pin positive. the Starblitz 250BAZ was 5.50V and the Achiever 630AF was 4.77V. The Yongnuo I bought was this one on Ebay http://cgi.ebay.com.au/ws/eBayISAPI....m=370273290693 The receiver has 6 contact points on the hotshoe. Jev, can you explain to me what the hotshoe control logic is? Is it something I can see or fiddle with in the unit? I suspect I have fried something in the receiver because it worked initially when used as a shutter release but wouldn't work subsequently after I had tried use it the other way as a flash trigger.
Doug

[jev]

Voltages are not likely to be the cause of death if I read that - 5.5V shouldn't really be a problem. Polarity seems to be rigth too. Than peek electricity can be high if there's a problem in the flashguns. Or a short-circuit where one of the contacts get grounded or get a voltage instead of being connected to an input. Hard to say, but the end-result is the same: receiver and flashgun are not compatible.

Since the receiver most probably is beyond self-repair, you could just as well open it up and check if there's anything blown out visible. If not, just throw it in the bin - without schematics it's not very likely you'll be able to repair it.

[bigrizz]

I have just bought a Yongnuo RF-602 Wireless Controller for my Pentax K200D on Ebay. When it arrived I eagerly connected the receiver to an old Starblitz 250BAZ I had laying around. This flash works fine on the hot shoe of the K200D. I mounted the transmitter on the camera hot shoe and fired the camera. The flash flashed. Tried again - nothing. Tried another old flash (Achiever 630AF) - nothing. The lights on both the TX and RX acted as they should as per the manual. Tried using the controller as a shutter release and although the lights acted correctly and a half press activated the auto focus it would not trigger the shutter. After a lot of tests I contacted the seller who sent me FOC another receiver unit. This time I tried it as a shutter release first and it worked just fine. Tried it as a trigger with the Achiever - nothing. Plugged it back in as a shutter release and this time it wouldn't work. All this points to a fault in the receivers caused by the flash units. Does anyone know if these older type flashes operate differently to the more modern ones? I think these flashes are triggered by a circuit being completed. Do more modern flashes operate like that or are they sent a seperate electrical charge to activate them? I opened up one of the RX units and nothing looked wrong with the wires or circuit board. Can anyone shed some light on whether I might be able to save the Controller or should I just chuck it in the bin? It's not the batteries cause I bought new ones. Any suggestions appreciated.
Doug

Hiya Doug. If I may digress slightly, how do you find the Starblitz 250BAZ for off-camera work? I'm looking at picking one up. Does it allow for full manual flash control? Is it any good?

Cheers

[Doug B]

G'day Bigrizz
Unfortunately I wasn't able to get the flash trigger working so haven't used the flash off camera. I actally got the flash off Ebay included with a camera, a bag and a lens which I bought only a little while back so haven't really used it at all. I have now returned the Yongnuo to the Chinese Ebay shop for a refund which they say they will give me. I haven't heard back from them yet so I'm not holding my breath.

[MarkChap]

Bigriz,
The Starblitz 250BAZ does not have manual controls, only a full power pop or 2 thyristor controlled aouto modes.

Don't use mine much, mainly if I need a full flash for effect, blow out a background etc