Posts tagged ‘Repair’

Keithley 775A Programmable Counter TCXO Repair

In my last post, I did a teardown of the Keithley 775A programmable counter/timer. And while feeding a 10 MHz signal from my Rubidium frequency standard, I noticed that the measured frequency was significantly lower (9.9981 MHz) than the nominal 10 MHz reading and could not be compensated by adjusting the TCXO fine adjustment screw alone. My suspicion quickly turned to the temperature controlled crystal oscillator (TCXO). Continue reading ‘Keithley 775A Programmable Counter TCXO Repair’ »

HP 8566B Spectrum Analyzer “YTO Unlock” Repair

While I was making a video on how to use HP 8671A as the frequency reference for an improved version of my simple DIY tracking generator for my HP 8566B spectrum analyzer, my spectrum analyzer suddenly decided to call it quits and displayed the dreaded “YTO Unlock” message. Although it wasn’t the first time it had done so — other times the “YTO Unlock” message only appeared once in a blue moon and rarely affected any measurements — this time however the problem seemed to be permanent and the error message wouldn’t go away. Continue reading ‘HP 8566B Spectrum Analyzer “YTO Unlock” Repair’ »

HP 8620C Sweep Generator Repaired

In my previous post, I did a teardown of an HP 8620C sweep generator along with an HP 86245A 5.9 GHz to 12.4 GHz RF plugin. A few of the plguin boards in the 8620C had leaked capacitors and also there seemed to be some sort of mechanical issue as no power was delivered to the transformer regardless of the power switch positions. So what I planed to do next was to restore the power to the unit and replace those bad capacitors and see if I could bring this sweep generator back to life. Continue reading ‘HP 8620C Sweep Generator Repaired’ »

Epson PowerLite 84 Multimedia Projector Teardown and Repair

I recently was given a broken Epson PowerLite 84 projector. The projector would not turn on when plugged in and there was no sign of life. So I decided to take a look at what was wrong with it. The potential reward is high since I do not have a projector yet and I could definitely use one for my home theater setup. A video of this teardown and repair is linked towards the end. Continue reading ‘Epson PowerLite 84 Multimedia Projector Teardown and Repair’ »

Lambda LQ-521 Power Supply Teardown and Repair

I bought a non-working Lambda LQ-521 linear power supply on eBay a couple of weeks ago. Usually I avoid knowingly buying something that is broken unless I am certain that I could obtain parts for it at a reasonable price. But buying broken linear power supplies is another story as most of the problem can be fixed with readily available components. Continue reading ‘Lambda LQ-521 Power Supply Teardown and Repair’ »