LeCroy 9300 Series Oscilloscope - need Part #

[pulseczar42]

Hello, I am repairing a LeCroy 9300 Series Oscilloscope. The specific model # is 9384AL, but I believe that information on any of the 9300 series should apply. The problem is evidently a burned out transistor and pot on the vertical deflection circuit for the CRT, but due to the burn damage I cannot make out the manufacturer's part # in order to find a replacement. If anyone has a service manual and can either provide a copy or simply reference the two components I am examining for me, it would be much appreciated. The parts I am interested in are referenced on the PCB as:

VR203A or Q202 - the BJT in the deflector
VR203B - an adjustment pot connected to the BJT

Again, these components are on the CRT board, which also houses the suction cup that connects directly to the CRT.

If anyone has one of these or has a service manual and can offer any assistance, it would be much appreciated. Feel free to reply here or PM me if you would like to help me investigate further. Thanks!

 

[carltongoodman]

I have the same problem! Have you by chance found out more about these parts?

 

[carltongoodman]

pulseczar42 suggested to me in a PM that this may be a 2SD669A (Q202) and a 100 Ohm pot (VR203B). I am going to see if I can find the transistor and try this out. If anyone else is reading this and has tried or will try it, please let us know of the outcome.

 

[carltongoodman]

I am having a devil of a time finding 2SD669A transistors. I have some 2N6517 sitting on the shelf, so I tried to put 5 of them in parallel. Yep, the screen turned on, but the transistors got pretty hot, hot enough to melt the hot glue which I put on the back of the circuit board to act as insulation. Looks like I'll have to get something closer to what I need from DigiKey.

If anyone wants to try this with putting smaller transistors in parallel, you will need a lot of them, much more than 5 TO92 packages. Also, don't forget to put ballast resistors on the emitters.

 

[yura717]

I am having a devil of a time finding 2SD669A transistors..

**broken link removed**
price is 0.75 $

 

[swallabat]

I have the same problem! Have you by chance found out more about these parts?

I have a 9314 in bits right now, and just in case it's helpful 2 years after the original question, Q201 is an irf740 on my rev B pcb. I seem to have no Q202 transistor though, but my q201 is right next to VR203.

And if anyone reading this can send me a diagram of the PSU in my scope I'd be very grateful...

Cheers, Steve C.

 

[karesz]

Hi Steve,

you have it - https://www.edaboard.com/threads/156498/#post947978 , pages 392/3 or 8-172/3...

Cheers, K.