Underwater Strobe Schematics (Sea & Sea YS-27DX)

[Chairman WAPSAC]

I'm hoping someone can help here.

I have a dead Sea & Sea YS-27DX strobe. The strobe flooded and subsequently let out all the smoke making the circuit work!. I appreciate that the damage may in fact be catastrophic but I'll have a go at fixing it anyway!

The problem is I don't have any schematics. Sea & Sea won't respond to my requests for schematics (no surprise there then). So I'm wondering if anyone has a schematic for this unit?

Thanks,

Ian

[William Sommerwerck]

You might be able to fix it by (forgive me!) shotgunning the likely
components.

I assume the unit has been thoroughly flushed with distilled water and
dried, and that you have cleaned/checked all the switches. The transformer
should be to see if it's open or shorted.

The caps and the semiconductors would be a good place to start.

[Jeff Liebermann]

On Sun, 3 Apr 2011 14:08:37 -0700 (PDT), Chairman WAPSAC
<chairma...@gmail.com> wrote:

>I have a dead Sea & Sea YS-27DX strobe.

Manual:
<http://www.seaandsea.jp/products/strobe/ys27dx/manual_AEKR.pdf>
<www.seaandsea.com/PDF_manuals/YS27DX.pdf>
<http://www.seaandsea.jp/products/strobe/ys27dx/>

>The strobe flooded

Fooded with what? Salt or fresh water?
Have you cracked the case yet?
How are you testing it?
Have you tested the fiber optic trigger cable?
<http://www.seaandsea.jp/file_master/adownload/50107_1.pdf>
Have you tried using a different camera flash to trigger it?

If salt water, and it was sitting for more than a few days, my
guess(tm) is the damage is more likely corrosion than component
failure. Look for green coppper sulfate crud around the PC board,
components, and transformer windings. It might pay to wash the entire
mess in clean water (several times) to remove any ionic contaminants.
It doesn't take much salt crust on the PCB to short out the hi-voltage
inverter that runs the strobe.

>and subsequently let out all the smoke making the circuit work!.

Nope. Water incursion doesn't not produce any smoke.

>I appreciate that the damage may in fact be catastrophic but I'll
>have a go at fixing it anyway!

Assuming the worst case is often a safe position, but not in this
case. My very limited experience with marine electronics (9.5 years
at Intech Inc designing marine radios) indicates catastrophic damage
is usually accompanied by massive corrosion. More commonly, corrosion
damage rots out the PCB, which prevents power of reaching components,
resulting in a dead circuit. It's very rare for corrosioin to bridge
the few places where a circuit resistive leak would blow something up.
Again, look for corrosion or contamination.

>The problem is I don't have any schematics.

Real techs don't need no stinking schematics.

>Sea & Sea won't respond to my requests for schematics (no surprise
>there then). So I'm wondering if anyone has a schematic for this unit?

Perhaps if you had your request for a schematic written in Japanese?

No schematic, but plenty of similar devices here:
<http://members.misty.com/don/donflash.html>
<http://members.misty.com/don/samflash.html>
Also, if there are any US patents on the device, they can be found at:
<http://www.google.com/patents/>

Good luck.

--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[N_Cook]

Chairman WAPSAC <chairma...@gmail.com> wrote in message
news:871a7c6b-b597-48bb...@glegroupsg2000goo.googlegroups.com
...

Don't know about flooding aspect. But inspect the bakelite of the socket
between the pins of the lamp, can break down from heat and volts and
generate smoke.

[Chairman WAPSAC]

OK thanks for the replies so far. Main reason for wanting schematics is that the board has a number of surface mount components and I can't see values on them.

Flooding was with salt water I believe.

Will be taking the strobe into work to place in ultrasonic bath but general condition inside is good with only a couple of areas where ingress is evident.

Have tried the transformer and switches and have buzzed out the battery lines. All looks fine so far. The LED which lights to indicate that the caps are charged and the unit is ready does not operate when batteries are installed and the unit is switched on. I've tested the LED and it's working fine and I've also used a camera flash and torch to try and trigger it which has no effect so I'm pretty sure the problem lies in the circuitry prior to the caps rather than in the triggering.

Cheers

[William Sommerwerck]

> The LED which lights to indicate that the caps are charged
> and the unit is ready does not operate when batteries are
> installed and the unit is switched on.

Handy tip... Do you hear the oscillator whining? Modern flashes are on the
quiet side, but you should be able to hear the transformer (or even the
transistors!) "singing" when you bend over.

If the charge circuitry is working, you should a couple hundred volts across
the caps.

[Chairman WAPSAC]

Yeah...have listened.....nothing.....checked the voltage across the caps....nothing.....maybe current limiting resistor in the circuit that's blown but the circuit isn't easy to trace and no idea what the components on the board are supposed to be as many of them don't appear to have markings other than whats on the board such as C3 D7 U2 etc. One suspect chip is a monostable multivibrator which should be easy to find but the SCRs are impossible to identify as are most the diodes, resistors and caps. Only double sided board so not the nightmare of multilayer but still it's two small boards and it's fiddly tracing it through.