Vector G08 Series Faq page 17

Most shorts will occur between the collector and either the base or emitter. If your test through
the connector reveals a short, pull the transistor and test it separately. If it is good out of circuit,
you may have accidentally shorted either the base or emitter against the heat sink, or the
transistor socket may have been bent. If the transistor tests bad detached from the heat sink, it is
ready for the garbage.
If you have to replace transistors, replace them all with the same type. I would use 2N6259s,
but these may be very difficult to find. Recently, I had someone try using the MJ15003
transistors that were original used in the design, and they had no luck with them (however,
2N6259s that I sent them worked just fine).
transistor is the MJ15024. I have used these as replacements myself and they appear to run
cooler than the original 2N6259s. I tested 4 of them in a G08 for 18 hours non-stop and they
worked fine.
Again, if y ou have a G08-001 (which is doubtful; I think all were returned to Electrohome), you
must use the MJ15003 and MJ15004 combination.
3) Resolder pins, joints, etc.
There are a few key points that generally need resoldered on these monitors.
Resolder all header pins. These are the pins that accept connectors. Check all the header pin
joints on the bottom of the deflection board, the current limiting boards (if present), the input
protection board, and the HV unit. Do not just reflow the solder; add a little fresh solder to each
pin (do not overflow onto adjacent pins, though). Double-check your work with an ohmmeter
when you are done.
Another common place where solder joints go bad is the HV regulator PCB. Sometimes the
regulators on this board get bumped a nd they break. Unscrew the HV regulator PCB from the
side of HV unit and resolder the pins to the HV regulators.
Be very careful when resoldering devices, as the screen has traces that lift very easily.
4) Do a visual inspection of the boards.
If you look at the bottom of the HV PCB or the bottom (or even top) of the deflection board,
you may see cut traces with jumper wires here and there, some resistors, transistors and diodes
soldered to the bottom. Do not let this frighten you. Assume that these are "factory
modifications" and leave them alone.
Look for burnt resistors, loose capacitors, broken solder joints, and broken transistor legs.
Resolder anything that looks suspect. If the deflection board has the current limiting boards,
carefully inspect them as they commonly have destroyed components. Reflow and increase the
quantity of solder on the joints for the large capacitors and the HV transformer. I have seen
broken solder joints cause monitor failures in both cases. Make sure the heat sinks on the small
G08 Vector Monitor Guide
My new recommendation for a replacement
Page 17 of 41