EBME Forums Forums Maintenance Technical Assistance Very old HP monitor

For the older ones amoungst us possibly, like Louis maybe!!
Anyone have any experience with an HP 70304A monitor & 78203C ecg module????
I'm only 38 so it is before my time.
A circuit diagram of the ecg module would be handy.

While us 'oldies' are investigating the possibility of finding documentation on the monitor at least, perhaps you might care to share the problem you are experiencing. Those of us who grew up having to fault-find to component level everytime, might be able to point you in a favourable direction if nothing else!

Good luck - Nick

Louis has service manuals for both of these devices, we still have a few knocking around, as Nick says, please be a litte more specific as to the fault, I have inspected two of these units recently, one was a PSU failure, the other was the L.O.T. (Schematic available on request, please e-mail me)
Regards.

Louis III

Sorry for the tardy response to your replies.
The problem is/was a blown capacitor on one of the ecg module pcbs (top pcb 78203 66501, back left corner). There are no designators on the pcb, so I can not give you a component code. The cap blew and as a consequence no markings are legible on the cap. Fault shows as a very low bpm reading, 1 or 2. The cap also took out a transistor, which I have been able to identify (BC 178).
The cap in question was orientated across the pcb, approx 25mm in from the board connector along the back edge, beside 2 ic's labelled 916 1826-0043.
Only kidding about the old bit.