HP Z3801A frequency standard

[G3UEQ]

Hi everyone,

I bought a Z3801A about 6 years ago, fitted internal psu etc and was working fine. However just gone to switch on unit after lapse of 2 years and all is not well.
Power light comes up but the main Lucent DC -DC converter gets hot pretty quickly. Checking supply rails shows TP6 at 2.4v (5v), TP8 at 6.7v(15v), TP7 at -7.5v(-15V).
The Datel DC-DC block is giving correct voltages. Disconnecting PSU connectors to main board and oven reveals no change, no electrolytics are getting hot. I guess this means the Lucent unit is most likely U/S, or does anyone know of a fault that can cause this.
Regards
Andy

[G3UEQ]

Subsequent checking shows TP8 (+15v) as measuring 5.2 ohms to ground , disconnecting L4 from the o/p of the Dc-Dc converter still shows 5.2 ohms on the converter side, so I guess I have a duff module, are they still available? It is a Lucent CW025ACL-M.
rgds
Andy

[W9GB]

Contact the time/gps reseller on eBay from China/Taiwan. Seems to have various parts for many different units.

[G3UEQ]

Thanks Greg
We deal with China etc at work and had not thought of that. Will put some feelers out.
73
Andy