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Jean-Paul, This was one of the classic RIFA caps from the 70s as you describe it, and the encapsulation (what remains) does appear to be crazed and yellowed (though there's no way to know if that was

Hi Siggi, Video suggests A sweep is OK on Christophe's scope. The video starts with B sweep but towards the end A sweep only is active and it looks like there is full sweep in all the time/div

Hey Christophe, I would suggest you read through this document ( https://vintagetek.org/troubleshooting-your-oscilloscope/). After that you can use the organized approach in this document to isolate

Hello- Many years spent in the surface mount assembly design and test "school of hard knocks" taught me the best methods to find defective components pulling excess current from power rails in

In the video the scope starts in B sweep. You can tell from the readout: You will notice that there are two readout positions at lower right for time/div settings. Somewhere on the video you can even

Hi Siggi, I was able to extract the front assy and clean the time-base selector but it did not change anything. Then I swapped the A and B hybrids sweeps, but same problem. I'll keep searching...

For some reason around here they are run on separate poles, typically on opposite sides of the road... -- Member of the toughest, meanest, deadliest, most unrelenting -- and ablest -- form of life

Ok. which supply is reading near zero?? From what you said, it's the 5 volt supply. Disconnect the boards at the main power supply. Does it work?? If so, the fault is on a board somewhere.? If

Morris, This is very much what you expect! If you set the sweep speed to 10nsec/div then the beam is on screen for 100nsec. It then has to wait almost 1msec (1,000,000 nsec) before the next trigger

I gather that the TTL chips are all in sockets. How about removing all of them and then testing the board to see if it still indicates shorts?

James, If you can find L4096 on the A10 board, near C4096, and unsolder one side, that will isolate the 5V supply to A10. See the power distribution diagram. Roger

Hi David. If you mean from the test points, then I have been doing that. The 5v and 15v read 6Ω and 14Ω respectively. The 15v rail goes up to 15Ω when J1731 is disconnected. If all the

It's kind of hard to tell from the video, but it looks to me that you have B sweep, but no A sweep. The two sweep hybrids are interchangeable, did you try swapping them? [email protected]> wrote:

""Nearby lightning can induce voltage spikes, as can a car hitting a telephone or a squirrel shorting out the terminals on an electrical transformer." Lightning; yes, squirrels; yes, cars hitting

I think I have a mental block going on. Too much time staring at the same several hundred components perhaps? Obviously not all the caps are on the 5v rail, so as I test across the caps, short of

Hi, for those interested, I have upload the PDF of my repair exercise in the file "Repair Tek 2430A NVRAMs.pdf" available in the file section. Christophe

Hello Leo, Thank you for your recommendations. I was finally able to put the scope in XY mode and I agree that it is kind of weird to make the time-base switch meet the XY position. But I did it and

Nice one for the clarification on the testing. I'll go and have another probe around. The PSU does limit the current, and it is set at 1 amp. The biggest problem is trying to figure out which

Interleaved: In that case, you will need to replace any possible destroyed parts and destroyed tracks.? It's not recommended. The idea behind the current limited supply (and it's a external lab

(Edit) Hi again Harvey. "If you can, run the 5 volts from a current limited supply (assuming 5 volts is bad), and then look at voltage drops across parts, mostly capacitors. Lowest voltage drop