Raymarine ST7000 component id and circuit needed

[Freddie]

Hi fellow cruisers, I have an ST7000 display unit that has suffered an internal blowout and has obliterated the top of an SMD component that is on the input side of the power to the PCB. It is a small square 4 legged component that looks like it could be an SMD fuse. I had a look at an ST4000 display unit which has a similar component with the numbers S8357 on it, and can find no listing for that either! If anyone has an ST7000 and is brave enough to open it and get the number off the part I sure would appreciate it! Any advice or circuit information greatly appreciated. Many thanks, Freddie in NZ.

[S/V Elusive]

Freddie - Can I suggest you call RayMarine Customer Service? As you know, RayMarine insists that there are NO Customer repairable parts on their units. Ergo they don't publish schematics or parts lists. What they WANT you to do is send the unit in, they will evaluate and tell you what is wrong and what it will cost to repair. I think that is a REALLY POOR way to handle that. But that is what their policy is.

Sooooo ... Call their CS - INSIST that you want to know What part, and part number you have is, and what it would cost to purchase from them (they may only have their internal part number available and so most likely couldn't get you an outside source number) Once you know what it is, you could possible shop it around - but I would suspect it wouldn't be that much more expensive to order from them.

They are NOT going to want to tell you what it is - they will claim that SOMETHING had to cause that part to fail (and they are right - but since you want to go it alone ... do it) and they will tell you it will probably fail because of the root cause. Tell them you have nothing to lose by attempting it yourself, and are they CUSTOMER Service or not?

Good luck.

[hellosailor]

Freddie, four legs doesn't sound like a fuse, they only need 2 contacts, in and out. Components with 4 pins might be brideg rectifiers or other things, although I doubt they'd stick a rectifier on the input to a display.

I did get a google hit on "S8357 smd" which leads to a Chinese electronics parts list. Using Googles translator, it shows an "S-8357 series" linked to PDf data sheets and a reference to "two triode". If you slug around in that, you might be able to get further with it but usually, something with that kind of hit means it is a custom part and there will only be one source for you: Raytheon/Raymarine.

No idea why it went kerflewie? No lightning strike, alternator and regulator tested and confirmed OK?

[Freddie]

Hi guys, many thanks for your replies. I have tried Raytheon Customer Service and agents many times and get the same answer, send it in and we will have a look at it and advise the cost of repair...............They refuse to part with any circuit information or parts. I certainly do not recommend them to anybody for this reason. As an electronic tech I find this sort of behaviour difficult to comprehend! I have tried googling for info but the parts are a bit obscure. Othe surface mount parts in RadioSpares and Farnells listing are similar but with no ID on one of the components apart from 4 legs it is very difficult. There is a listing for a double semiconductor fusr and a bridge rectifier in the Farnell parts book that looks like the same package, so I am going to try a bit of reverse engineering and draw out the input circuit just to be obstinate! I will put it on this website as it may be useful to others and Google should also find it eventually. Once again, thanks for taking the time to reply. All the best, Renfred.

[hellosailor]

Freddie-
From the four legs, and the odd "double triode" reference on the web, it sure does sound like some kind of fuse/bridge rectifier (sacrificial bridge rectifier??) in there. Do you have a working Raytheon display of some kind, that you could pin out and see if that's how the "black box" behaves?
Does it make some kind of sense to have that on the data input to a display unit?? (Compulsive engineering? Or spike/reverse protection?)

[DeepFrz]

I came up with this in my search, but I am far from confidant that it is right.

S8 BAT14-099 Sie NQ SOT143 Dual schottky

HTH

Deep

[markpj23]

Freddie - did you get the part number you needed? I'm back aboard now and will have a look at my unit if you still need the info.

[Alan Wheeler]

Hi Freddie, yeuuup, that's why I didn't want to have raytheon on board. Not the products fault, it is that stupid attitude of Lusty's. That they will not part with any info or parts to "non-authorised" repair agents. The repair agent does nothing more than replace the board, as they do not consider them repairable. Mainly because very few agents have the ability to work at component level anyway. And I suppose to be honest, the board should be replaced. It's something you want to be bullit proof, you don't want to risk it maybe failing in the future.
Do you know why it failed??? What happend???
There must be a reson why something like this failed and I would be worried about what else is fried or stressed beyound help. Reverse polarity I would have thought would be either fused or have some form of protection to stop a problem.
I suggest it maybe a regulater device to maintain a constant 12V or what ever the unit operates on. Just a guess though.