[GregS[_3_]]

In article , Bob Larter wrote:
GregS wrote:
In article , "William Sommerwerck"
wrote:
If I understand it correctly, poking the tranny (something I would never
do!) caused the corresponding channel to drop in and out.

So... are you ready to swap trannys?

(I'm a bit confused. Does this unit actually use driver transformers? It's
hardly a recent model, but I thought driver transformers had disappeared a
few years before this series.)



I think he meant trany istor.

Used to have bad transistors in some Tek scopes that ran hot.
over time the internal connection would become unstable and poking
would bring it back. Probably just the solder joint.

That'd be my diagnosis too. Happens all the time with heatsinked parts,
because the pins don't get hot enough to 'wet' properly when they go
through the wave-soldering machine at the factory.


Thats what happens to boards, but I'm not saying that. Its
the connections INSIDE the transistor that were going bad.
Poking the transistors vibrated the internal connections.
The only way to fix the problem was to install new transistors.
These were the ones in the 5000 series for the vertical and horizontal
drives.

greg