19V2000 Recap Question

I would use the 1uF caps. As long as they've been stored in a reasonable way, they should be fine. (And if they are a decent brand like Panasonic or Nichicon, they'll definitely be fine.)

Caps are not as critical on THESE monitors, at least in terms of not replacing them causing bigger problems. Worst case if a cap is bad, the monitor just won't work. But it won't damage anything. Also, while the spot killer caps are important to the operation of the monitor, and the original tantalum caps DO go bad (and will cause the spot killer to not work properly), those four caps don't work that hard. So if the monitor works once you install the 1uF's, you're probably fine leaving them in there, and not replacing them again.

Cracked solder joints on the headers of the deflection board are more likely to actually cause transistors to blow. But as long as you reflow those, you'll be ok.
 
Well, I didn't quite get to the HV diode temperature check on account of my failure.
  • I did use the screwdriver method to discharge the CRT, however it had been of for a few days before I did the discharge. I heard/saw no spark.
  • Did the cap rework. Cleaned the HV diode springs/boots.
  • Re-installed boards, fail.
  • Discharged the CRT with screwdriver, saw spark.
  • I did test HV diode with 40 V --> 12 kohm --> HV diode --> GND. Did measure a very small voltage drop (sub 1 volt?) with diode connected forward polarity (vs. no small drop as expected when connected reverse polarity). I wonder if I needed to use a smaller resistor (I think I saw someone use 240 ohm), but then I thought I saw specs like 10 mA max forward current. Of course if that's true, then a momentary discharge through screwdriver you think would assure destruction I'd think.
  • Did a super good job of cleaning the diode springs/boots. Took them out (broke off the flyback side cap. Re-soldered it back on.
  • Re-connected. Same fail symptoms.
Any thoughts? Here's the fail:

IMG_20250708_203716100_HDR.jpg
 
Your HV is too low. (Which you can tell by the way the screen is super expanded/bloomed.) Either your diode is bad, or the connections to it aren't good enough. Or there's something else wrong in the cage.

If you're going to work on these monitors, you really need an HV probe. Not only is it good for safely discharging tubes, but if you're doing anything with HV, you'll need a probe to measure and properly set the HV level when you're done. You can also monitor the HV level as you power the monitor on for the first time after doing any repairs, and see what the HV level is (and shut the monitor down quickly if it isn't correct). My guess here is you're probably only getting 6-8kV or so at the tube, not the 14.5kV it should be.

A Fluke 80k-40, or B&K Precision PR28A are the ones most folks here use. You can get a used Fluke on ebay for around the price of a new PR28A, both should be under a hundred bucks.

And/or, if you want to send the cage in, I can repair it for you. PM if interested.
 
I was fearing that... I did order a 80k-40 off ebay. I have some other high voltage things to fix... and yeah, I'm going to feel a lot better. I'll try I think once more to fix it. I won't make it for this weekend, but I have some backup plans. But I'll keep you in mind if I fail again. Thanks.
 
I was fearing that... I did order a 80k-40 off ebay. I have some other high voltage things to fix... and yeah, I'm going to feel a lot better. I'll try I think once more to fix it. I won't make it for this weekend, but I have some backup plans. But I'll keep you in mind if I fail again. Thanks.

If you have any other questions, post them here. Happy to help.
 
Any issues with using a screwdriver to discharge a CRT? There is some talk about it possibly damaging the HV diode, but I can't seem to figure out why. Hoping to bust this myth.
 
Any issues with using a screwdriver to discharge a CRT? There is some talk about it possibly damaging the HV diode, but I can't seem to figure out why. Hoping to bust this myth.

I've pushed back on that claim of screwdriver damage, as there hasn't been much evidence of it.

If you want to be extra safe, just let the monitor sit for 24 hours after powering it off. Most of the charge will bleed off on its own. Then you won't get much of a pop, if any.

However, if you're going to work on these, you really should have an HV probe anyway, for the reasons mentioned a few posts above. If you aren't working on the HV cage, you don't need to discharge the CRT, if you're just going to remove the deflection board. But if you are going to work on the HV, you need a probe to calibrate the HV level when you're done.
 
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