Older Flashguns.


vic cross

Link Posted 26/11/2018 - 19:11
I have two TR power packs for both my 400's so maybe I'll try that. Thanks.
CHEERS Vic.
Born again biker with lots of Pentax bits. Every day I wake up is a good day. I'm so old I don't even buy green bananas.

K10D

Link Posted 26/11/2018 - 19:28
Vic, the electrolytic capacitor in the flashgun is the problem area. With age, they dry out which in simple terms means they stop being a capacitor. Just as with old HiFi amps, the capacitors are replaced with modern equivalents, much better, smaller and more reliable. This does mean that the flashgun needs opening so not something that most will attempt.

Any slight recovery will be just that.

Capacitor replacement is a common thing, just make sure that the correct operating voltage for the capacitor is known. Easy to do when the original is removed as the capacity and voltage will be on the component.




Best regards
cameradextrous _ Motorcycles etc. link

McGregNi

Link Posted 26/11/2018 - 20:21
And this is the usual place where someone always adds that you have to be extremely careful not to touch something inside that is going to give you a nasty shock....

(sorry, I'm no techie, someone else will have to be more specific about what exactly not to touch!)
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Last Edited by McGregNi on 26/11/2018 - 20:21

johnha

Link Posted 26/11/2018 - 22:47
McGregNi wrote:
And this is the usual place where someone always adds that you have to be extremely careful not to touch something inside that is going to give you a nasty shock....

I wouldn't advise disassembly. You have to be extremely careful, the capacitors are huge and are able to store huge amounts of energy (usually at very high voltages). They store the trigger voltage for the tube (which is always hundreds of volts irrespective of the voltage across the hotshoe contacts).

Electrolytic capacitors are polarised (marked on the can), you need high quality and precise soldering anywhere near them. A 'normal' electrolytic capacitor is the size of two LR44 batteries, these things are the size of C cell batteries.

I had a tiddler flashgun stop working - GN 28, despite my attempts to drain the charge (the fault was between the TEST switch and the cap), I received a huge belt from the capacitor (along with beautiful iridescent blue sparks...).
PPG Flickr
Last Edited by johnha on 26/11/2018 - 22:50

K10D

Link Posted 26/11/2018 - 23:01
It's horses for courses John. I've done a few flash guns over the years and not been zapped. You are right about the shock hazard though and the job should only be done by competent technicians or some one who works in the field of electronics. I would not expect Vic to attempt the job, no disrespect to him.

The capacitor can be safely discharged with a 1M ohm 1/4W resistor on fly leads.

Best regards
cameradextrous _ Motorcycles etc. link

pschlute

Link Posted 26/11/2018 - 23:07
Vic hasn't posted for four hours...are you ok mate ?
Peter



My Flickr page

vic cross

Link Posted 27/11/2018 - 08:05
Good morning Peter. Yes I'm fine thanks. I had to go out last night for a couple of hours.
I'm going to charge up my NI-MH C cells today and give that a try. If that doesn't work then does anybody know where I can get the two guns fixed. (New capacitors) or whatever it takes. I'll be back later today OR tomorrow to let you all know how it goes.
CHEERS Vic.
Born again biker with lots of Pentax bits. Every day I wake up is a good day. I'm so old I don't even buy green bananas.

pschlute

Link Posted 27/11/2018 - 11:48
vic cross wrote:
Yes I'm fine thanks.
.

Just was concerned you may be sitting at A&E with a flashgun welded to your hand
Peter



My Flickr page

vic cross

Link Posted 27/11/2018 - 12:15
No thanks Peter. Iv'e spent enough time in A&E in the last 2 & a half years. 2nd. June 2016 my wife Sheila had a stroke which has left her with "Aphasia" (Can't speak properly and forgets things) Because of all the worry one month later I ended up with pneumonia and by the end of the year this caused my own immune system to attack my kidneys so now I'm on pills to kill my immune system as my kidneys are now up to 25%. The problem is that if I get the slightest infection of any kind I end up in A & E. Last year I only got out of hospital on Christmas eve. All of this has left me knackered. My muscles ache and I get short of breath just fastening my shoe laces. I Haven't had a holiday for two years and haven't been out with a camera for about 9/10 months. HOWEVER. I have signed up at the local tech collage on a 10 week evening course starting Jan. 8th. on photography just to get me out and doing something. It's mainly a studio course. I have hospital appointments all through next year right up to Dec. 2019.
Enough of my problems.
Iv'e charged up a set of "C" cells and put them in a TR Powerpack plugged it into my 400t switched it on and now I must wait and see if it brings the flash to life again???.
As I asked yesterday if anybody knows where I can get them fixed please let me know.
CHEERS Vic.
Born again biker with lots of Pentax bits. Every day I wake up is a good day. I'm so old I don't even buy green bananas.

pschlute

Link Posted 27/11/2018 - 13:07
Sorry to hear that Vic. I sincerely hope 2019 will be a better year for you both.
Peter



My Flickr page

McGregNi

Link Posted 27/11/2018 - 14:03
I second that! Flashes are clearly the least of your worries Vic, but no doubt having something more fun to focus on is a good thing, and that course sounds like a good idea. I hope you will wow them all with the legacy Pentax gear! Here's hoping for a healthier 2019 for you both.
My Guides to the Pentax Digital Camera Flash Lighting System : Download here from the PentaxForums Homepage Article .... link
Pentax K7 with BG-4 Grip / Samyang 14mm f2.8 ED AS IF UMC / DA18-55mm f3.5-5.6 AL WR / SMC A28mm f2.8 / D FA 28-105mm / SMC F35-70 f3.5-4.5 / SMC A50mm f1.7 / Tamron AF70-300mm f4-5.6 Di LD macro / SMC M75-150mm f4.0 / Tamron Adaptall (CT-135) 135mm f2.8 / Asahi Takumar-A 2X tele-converter / Pentax AF-540FGZ (I & II) Flashes / Cactus RF60/X Flashes & V6/V6II Transceiver
Last Edited by McGregNi on 27/11/2018 - 14:03

K10D

Link Posted 27/11/2018 - 15:04
Vic, when you put new battery's on the 400's, could you hear the oscillator whining? The most common cause of old dead flash guns is the capacitor but normally you may hear the oscillator working as it tries to charge the capacitor. Since you have used the TR power pack, it generates the full voltage required to the gun without the gun needing to use the internal oscillator and if the capacitor is usable, the ready light should illuminate.

There's a company in London that might be able to help link. Downside is pricing. Most of the repair companies will be wanting around sixty pounds or so.

Best regards
cameradextrous _ Motorcycles etc. link

vic cross

Link Posted 27/11/2018 - 15:54
Hi Gary. Iv'e just come to check at 3.44pm and nothing. There is no whining from either of the guns and the TR Powerpack light which came on at first has gone off. I've just checked the batteries with my voltmeter and they are completely drained. They read 1.37 to 1.39 and now read .03 .04.
I'll recharge all 12 batteries and try again tomorrow. In the meantime thanks for the link. I'll look it up now.
CHEERS Vic.
Born again biker with lots of Pentax bits. Every day I wake up is a good day. I'm so old I don't even buy green bananas.

vic cross

Link Posted 28/11/2018 - 08:07
Wed. 28th. 8am. Just checked again with fully charged NiCads in my TR pack. ALL IS GOOD. Both guns now fully working.
Thanks to all of you for your suggestions. Now it's trial and error to see if I can make them work all wired together with the 280 gun.
Great joy in the fundimold.
CHEERS Vic.
Born again biker with lots of Pentax bits. Every day I wake up is a good day. I'm so old I don't even buy green bananas.

vic cross

Link Posted 28/11/2018 - 15:42
Wed. 28th. 3.35pm. I've just tried my 280 gun with and without the Hot Shoe Grip Direct on my K3ii and also my two 400's direct on my K3ii and they all worked perfectly.
Who's a happy bunny then.
Once again thank you all for helping a retired "MECHANICAL" Engineer with an electrical problem.
CHEERS Vic.
Born again biker with lots of Pentax bits. Every day I wake up is a good day. I'm so old I don't even buy green bananas.
Add a Comment
You must be registered or logged-in to comment.