IFR 1000S repair / troubleshooting

[rkeith2]

I am looking to raise from the death bed my IFR 1000S. So far I found the 1 watt resistors on the main xfmr/bridge area burned open. I found a 150 uf shorted and replaced that and the resistors. I had the unit lit up for a while and then I saw a 150 uf burining in the scope are and then replaced that one. I now have a stable power supply with scope operating and spectrum noise floor, however the right lock light is out and the bulb checks good. I looked at the output on the 80 ~ 90 low PLL board and it reads around 7500 and does NOT change with thumbwheel. This is where I am stuck at this time.

[Astro Spectra]

I know nothing about the IFR but with two dead so far I'd be replacing ever other electro of the same type.

[d119]

I know nothing about the IFR but with two dead so far I'd be replacing ever other electro of the same type.

Agreed. With an instrument of that age, you can rest assure capacitors are starting to dry out. Replace ALL of the electrolytics.

[rkeith2]

Most are tantalums

[rkeith2]

OK - I found a problem in the 80~90 low pll and I have lock now and many operations are good except generate.

Its making me work -

[d119]

Well once you become an expert, I'll send you my 1000 to fix.