Fix Another Tek 465

2018/12/30

Don't be surprise. I got 2 of broken 465 with a Digital storage add on years ago.

Recently i fix one of them. This is another one.

Black Screen

Off cause black screen, typical PSU failure for a 40 years old equipment. Luckly, it's so clean inside and outside. At +55V TP, there is a full range 120Hz sin wave, but the 110V TP seems ok. Because 55V rail is providing the reference to any other supply rail, this suggest the C1513 is most likely totally dry. Plus the 15V to HV fuse blew.

Could you find out how I fix the capacitor?

I don't have a suitable Fuse, another fuse socket is parallel with old one.

Success! so easy? Enjoy the photo.

Low Intense

It works well after fix the capacitor, then i put into the case, bad news, the sweep line disappear! after turned it intense up to max, the sweep line come up again. Damn!

But i remember a case which the chopped generator transformer broken leading to Low Intense.

Luckily, while pull out the Chop cable, bingo! exactly same problem.

Chopped mode seems a bummer for Tek 465, it also might cause other intense problem.

Do't forget to un plug this cable, it's quick to isolating the CHOP circuitry.

Wired Fan Fault

One annoying problem is the Fan. It always on the full speed running.

Checking the RT1696, R1698 seems OK. The Q1698 also fine.

I don't want to tear down everything just for take out this fan module.

So, one thing should happen if I manually make the Q1698 shutdown by shorting CR1699.

Yes, it did make the Fan speed back to normal. And the Fan stay normal while I remove the short( the tweezers)!!! Unbelievable!

I just let it go, whatever it is, I don't care.

Blacking screen Again

Days latter, it went black again, suddenly, the fuse blew. I replace it with a 10 A current meter, off cause the current surge to 3A for a while and the magic smoke came out somewhere.

Sound familiar, first thing is checking the C1419, and it is dead short. I burning it to short permanently while i connecting a current meter on the fuse. It would recovery after black if you power off a while. before i done that.

No more other problem since then. and the Digital storage module is working!

What a surprise!