Need advice on where to look for Strobe modification.

Thread Starter

bloodreyna

Joined May 28, 2021
5
I am a photographer with a little bit of electronics background. I know that these devices can be taken apart and fixed, modified, etc. to improve performance. Basically I have these strobes and occasionally they misfire, ie they don't fire because, they don't stay cool, they aren't powered properly, the wireless signal was bad. Those are the typical things. I have gone through quite a few of these products and I'm tired of throwing money at them all when they all have the same issues. So I am thinking why not modify these somehow to improve their performance. I am aware that there are large capacitors in the strobes that can blast you to kingdom come! Just wondering if anyone knows anything about where to start with something like this. If I can replace a sensor, change a resistor, hack the battery, something like that to make it work better.
 

Papabravo

Joined Feb 24, 2006
16,160
I am a photographer with a little bit of electronics background. I know that these devices can be taken apart and fixed, modified, etc. to improve performance. Basically I have these strobes and occasionally they misfire, ie they don't fire because, they don't stay cool, they aren't powered properly, the wireless signal was bad. Those are the typical things. I have gone through quite a few of these products and I'm tired of throwing money at them all when they all have the same issues. So I am thinking why not modify these somehow to improve their performance. I am aware that there are large capacitors in the strobes that can blast you to kingdom come! Just wondering if anyone knows anything about where to start with something like this. If I can replace a sensor, change a resistor, hack the battery, something like that to make it work better.
Fooling around with things that can kill you is a terrific way to win a Darwin award. Modern manufacturing methods have all but eliminated the possibility of DIY improvements. Gone are the days when things were hand wired and the components loose packed into a package. Take one apart an you're liable to find a printed circuit board that was assembled by automated machines and is cheaper to replace than troubleshoot. If you still want to proceed you should gather some basic information on safety, start with basic circuits and work your way up. This journey will take a while so you can't be in a hurry. Most important is to learn from others the things you should and should not do. Like for example -- don't work alone with high voltage.
 

DickCappels

Joined Aug 21, 2008
7,442
I would approach this by searching for information on the internet. If you are having these problems the chances are that many others are having the same problems. Some of these may have solved the problem and published the solution.

It is unlikely that you will recruit help upgrading a broad set of products on a forum like this.

If you are looking ideas to repair a particular strobe you can publish as much as you know about the strobe and probably get help identifying the failure and devising a repair, maybe better than what you started with.
The best place to discuss the repair of a specific strobe would be in the Technical Repair forum https://forum.allaboutcircuits.com/forums/technical-repair/
 

Ian0

Joined Aug 7, 2020
2,252
I am a photographer with a little bit of electronics background. I know that these devices can be taken apart and fixed, modified, etc. to improve performance. Basically I have these strobes and occasionally they misfire, ie they don't fire because, they don't stay cool, they aren't powered properly, the wireless signal was bad. Those are the typical things. I have gone through quite a few of these products and I'm tired of throwing money at them all when they all have the same issues. So I am thinking why not modify these somehow to improve their performance. I am aware that there are large capacitors in the strobes that can blast you to kingdom come! Just wondering if anyone knows anything about where to start with something like this. If I can replace a sensor, change a resistor, hack the battery, something like that to make it work better.
You should find:
a large capacitor with the xenon tube connected directly across it
a trigger transformer with its output wire connected to the outside of the xenon tube
a thyristor circuit to pulse the trigger transformer
a circuit to charge the capacitor. If it is a 230V mains operated device, then that is probably just a rectifier and a current-limiting resistor.
Which part do you want to improve?
 

MisterBill2

Joined Jan 23, 2018
8,781
Obviously these are not simple strobe-flash packages. No mention is given about iif they are battery powered or mains powered, and that does make quite a bit of difference. The comment about not staying cool could certainly point towards part of the problem. Heat is usually an enemy in electronic devices.
Certainly having a circuit schematic drawing for us to see will be a good starting point.
But my first guess, based on the complaints is that they overheat and the battery voltages drop.
 

Ian0

Joined Aug 7, 2020
2,252
Generally, the power supply is allowed to run all the time. When the tube has been triggered the power supply current is not sufficient to keep the tube running and it extinguishes once the capacitor is discharged. However, if the tube gets hot, the current required to keep it conducting reduces and it fails to extinguish. Current keeps flowing and the capacitor cannot recharge. The current flowing is barely enough to keep it alight, but the cycle is stopped.
 

MisterBill2

Joined Jan 23, 2018
8,781
If it is some sort of inverter supply running on batteries, and the photog is taking a lot of pictures, that inverter is working quite hard. THAT will indeed make it hot. And while flash tubes do get warm, or even hot, I have never heard of one staying conductive. I didburst one, but that was from firing it with a much higher voltage than it was rated for. About 10X the spec rating. Also used a bigger cap. And I did see a mains powered flashburst the big capacitors when it went into a fast-flashing mode for a few minutes. But that was a very high power unit used for crash test photography.
 

Reloadron

Joined Jan 15, 2015
5,934
I am a photographer with a little bit of electronics background. I know that these devices can be taken apart and fixed, modified, etc. to improve performance. Basically I have these strobes and occasionally they misfire, ie they don't fire because, they don't stay cool, they aren't powered properly, the wireless signal was bad. Those are the typical things. I have gone through quite a few of these products and I'm tired of throwing money at them all when they all have the same issues. So I am thinking why not modify these somehow to improve their performance. I am aware that there are large capacitors in the strobes that can blast you to kingdom come! Just wondering if anyone knows anything about where to start with something like this. If I can replace a sensor, change a resistor, hack the battery, something like that to make it work better.
I guess if I were to pursue this I would start with good equipment. Good professional grade equipment. That's where I would start before I tried to modify something that is unreliable. When it comes to strobes for photography they can play a few roles. The classic firing an SCR when we want a slave flash in sync with another flash and the old classic of using multiple flashes while holding a shutter open and bouncing a ping pong ball. Before we can modify anything with hope of improvement we absolutely need an accurate and correct schematic of what we have. That is not always easy to have at hand.

A really good strobe for general purpose use was the old Gen Rad (General Radio) 1531 series which had a good manual, did not need fixed the day you got it and gave years of service. Anyway good stuff does not come inexpensive and I am sure you know that based on cameras. The safety aspect has already been covered so we won't beat that up any further.

Ron
 

AnalogKid

Joined Aug 1, 2013
9,257
There is no useful information in your post. What strobes? Manufacturer, model number, age, technology (LED or tube) - your know, information.

Finding schematics online will be difficult, but photos of the internal circuit boards and wiring will help us determine what is and is not possible.

ak
 

MisterBill2

Joined Jan 23, 2018
8,781
There is no useful information in your post. What strobes? Manufacturer, model number, age, technology (LED or tube) - your know, information.

Finding schematics online will be difficult, but photos of the internal circuit boards and wiring will help us determine what is and is not possible.

ak
I am guessing that these are all battery powered strobe-flash packages, and possibly of an entirely adequate quality. So the first thing would be to evaluate the heat sinking arrangement for the inverter transistors. It might possibly work to simply improve the heat sinking. But that might be quite complicated.. It might also be quite expensive, or even impractical. So the very first thing is to understand the current strobe-flash units. A circuit may not be easily available.
 

Sensacell

Joined Jun 19, 2012
2,831
To improve the design, you would need to be better than the original designer, is this a reasonable statement?

You might be able to make it work better by "dumbing it down" - you want it to fire reliably? make it wired. You want it cooler? add a big ugly fan.
 

MisterBill2

Joined Jan 23, 2018
8,781
To improve the design, you would need to be better than the original designer, is this a reasonable statement?

You might be able to make it work better by "dumbing it down" - you want it to fire reliably? make it wired. You want it cooler? add a big ugly fan.
No, one does not need to be beter than the original designer. One needs to have different design goals. For the majority of consumer products the first design goal is minimum cost to produce. Often the next priority is the maximum number of features thattheproduct can be claimed to have. toward the bottom of the list are reliability and durability. So making changes to improve the reliability simply requires being able to see where the weak points are, and how to improve them. Often this means adding components or materials, such as bigger and more effective heat sinks, or possibly changing the inverter transistors to more efficient types..
All designs are a compromise, the difference being what variable is being compromised. Most of the time, for consumer items, it is cost that is being minimized.
 

Thread Starter

bloodreyna

Joined May 28, 2021
5
No, one does not need to be beter than the original designer. One needs to have different design goals. For the majority of consumer products the first design goal is minimum cost to produce. Often the next priority is the maximum number of features thattheproduct can be claimed to have. toward the bottom of the list are reliability and durability. So making changes to improve the reliability simply requires being able to see where the weak points are, and how to improve them. Often this means adding components or materials, such as bigger and more effective heat sinks, or possibly changing the inverter transistors to more efficient types..
All designs are a compromise, the difference being what variable is being compromised. Most of the time, for consumer items, it is cost that is being minimized.
Thanks for all the responses!

A few people were asking about the brand, it is a Westcott FJ400 which is thought to be a clone of a Jinbei strobe. It is battery powered but has an option for AC power that runs through the battery charging port. It supposedly has a fan but I have never heard it. Not a bad strobe but it does misfire, especially at higher power which is the whole reason I bought it, maybe it is just Chinese junk and should be abandoned?

I supposed the battery could be causing it to misfire as that is a huge source of issues on say a Canon 600EX which runs on AA's.

I can get some pictures if anyone wants to see what it looks like on the inside.
 

anniel747

Joined Oct 18, 2020
1,122
Thanks for all the responses!

A few people were asking about the brand, it is a Westcott FJ400 which is thought to be a clone of a Jinbei strobe. It is battery powered but has an option for AC power that runs through the battery charging port. It supposedly has a fan but I have never heard it. Not a bad strobe but it does misfire, especially at higher power which is the whole reason I bought it, maybe it is just Chinese junk and should be abandoned?

I supposed the battery could be causing it to misfire as that is a huge source of issues on say a Canon 600EX which runs on AA's.

I can get some pictures if anyone wants to see what it looks like on the inside.
Did you try this? https://www.fjwestcott.com/firmware
 

Yaakov

Joined Jan 27, 2019
3,161
Thanks for all the responses!

A few people were asking about the brand, it is a Westcott FJ400 which is thought to be a clone of a Jinbei strobe. It is battery powered but has an option for AC power that runs through the battery charging port. It supposedly has a fan but I have never heard it. Not a bad strobe but it does misfire, especially at higher power which is the whole reason I bought it, maybe it is just Chinese junk and should be abandoned?

I supposed the battery could be causing it to misfire as that is a huge source of issues on say a Canon 600EX which runs on AA's.

I can get some pictures if anyone wants to see what it looks like on the inside.
So can you be more specific about what you mean by "misfire"? Do you mean it's not cycling fast enough and so when you try to shoot it doesn't fire?

You mention the Canon 600EX which I use, and while cycle time can be extended if I dump the whole capacitor charge, I have never had a "misfire", and if I use an HV battery pack it cycles after full power in less than a second.
 

Thread Starter

bloodreyna

Joined May 28, 2021
5
So can you be more specific about what you mean by "misfire"? Do you mean it's not cycling fast enough and so when you try to shoot it doesn't fire?

You mention the Canon 600EX which I use, and while cycle time can be extended if I dump the whole capacitor charge, I have never had a "misfire", and if I use an HV battery pack it cycles after full power in less than a second.
Yes by misfire I mean it fails to fire. Running two of them at about the same power settings one of the FJ400's tends to misfire more frequently than the other.

And to the previous poster, I am on the latest firmware from Westcott and have been updating all my gear as frequently as possible.
 

Yaakov

Joined Jan 27, 2019
3,161
Yes by misfire I mean it fails to fire. Running two of them at about the same power settings one of the FJ400's tends to misfire more frequently than the other.

And to the previous poster, I am on the latest firmware from Westcott and have been updating all my gear as frequently as possible.
Wait. This is important. Do you mean fails to cycle in time for the next flash or fails to fire in spite of being charged?
 

anniel747

Joined Oct 18, 2020
1,122
Yes by misfire I mean it fails to fire. Running two of them at about the same power settings one of the FJ400's tends to misfire more frequently than the other.

And to the previous poster, I am on the latest firmware from Westcott and have been updating all my gear as frequently as possible.
You don't hear the fan of the misfiring one only?
 

MisterBill2

Joined Jan 23, 2018
8,781
A slower recharge would certainly cause a non-fire if taking pics in a fast sequence. But it might be a poorly wrapped trigger wire on one unit. Or it might be a bad connection in the trigger circuit wires. Try re-soldering those connections.
 

Yaakov

Joined Jan 27, 2019
3,161
A slower recharge would certainly cause a non-fire if taking pics in a fast sequence. But it might be a poorly wrapped trigger wire on one unit. Or it might be a bad connection in the trigger circuit wires. Try re-soldering those connections.
The TS is using the word "misfire" but I think he is complaining about cycle time, not a failure for the flash to fire when indicating ready. The question is, if it is the former, is the flash in spec for cycle time? If so, it is unlikely he is going to be able to have any impact on performance as compact strobes like that one are highly optimized to get the most out of the space available.
 
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