PVM-9044Q Problems

[Joko3]

I recently got burned two times in a row on Yahoo Auctions Japan buying PVM-9044Q monitors.

One has vertical collapse, and the other one (likely) has a bad tube as blue doesn't show up well at all (messing with blue gain and bias does hardly anything).

Anyway, I was wondering, because these are both the same monitor, could I swap some parts around to make a working one? If yes, where would be the best place to start? What are the safety precautions I need to take? I am decent at soldering, but I have never messed with CRTs before. Anytime our displays needed to be repaired in the Navy they brought in outside help while we just kind of watched them...and the last time I watched was over ten years ago lol.

YAJ essentially has no buyer protection for this stuff, so I can either send these to the dump or try to make a working one. I posted on the PVM group on Facebook as well, but I figured somebody here might know something as well.

Pictures will be in the next post uploaded through my phone.

 

[Joko3]

 

[hatmoose]

These are fun little monitors, the perfect size and spec for a bench test. Most content looks stunning on a screen this size. Well worth the effort IMO.

Option 1: fix the vertical collapse, it will either be the vertical IC or another problem in the horizontal section, many people would suggest a recap, but that is a lot of work.

Option 2: swap the tubes over.

My personal preference would be to swap the tubes. Sounds scary but it’s not. You can swap the entire tube unit, yoke, rings, convergence strips and all, it will be a drop in replacement.

If you have the service manual it will show how to extract the tubes.

 

[Joko3]

What about swapping just one of the boards?

I thought swapping the tube would be good too, but I’m scared shitless of it lol. Doesn’t this mean messing with those flyback transformers? Scary stuff

 

[hatmoose]

What about swapping just one of the boards?

Oooh, that’s a much better idea - I just learned how to do a tube swap, so of course every problem looks like tube swapping is the solution to me.

But objectively yes, swapping the A board would accomplish the exact same thing, and be much quicker.

 

[nobody]

@Joko3, it's actually not that bad, first one has probably a failed thyristor in the vertical deflection circuit, second looks to have cut off sets way too high for blue.

 

[Joko3]

https://elektrotanya.com/sony_pvm-9041qm_pvm-9044qm_sm.pdf/download.html#dl

Would it be the D board on page 32 where the problem is for the vertically collapsed one? Where do I look for the cut-off on the one with bad blue? Any help would be greatly appreciated. It's literally been 10+ years since I've looked at block diagrams and am a bit lost.

 

[kikaso]

@Joko3, it's actually not that bad, first one has probably a failed thyristor in the vertical deflection circuit, second looks to have cut off sets way too high for blue.

Apologies to @Joko3 for derailing the thread but is this supposed to be a joke in your sig, @nobody

This is pretty fucking racist.

 

[hatmoose]

is this supposed to be a joke in your sig, @nobody

My SIL is mainland chinese too and my brother lived in Chengdu for many years, it's how they met. Both of them are unaware of the history and the pain, and more recently the courage and the progress. My SIL especially - it's so far outside of the cultural context that she cant know.
I'm not so different - I didnt even see this for what it was until it was pointed out.
Pretty sure that this is the same situation, @nobody wont be emotionally attached to that image and it's not really relivant to Arcades or Projects - We can do the right thing and change it for something more arcade related.

 

[hatmoose]

https://elektrotanya.com/sony_pvm-9041qm_pvm-9044qm_sm.pdf/download.html#dl

Would it be the D board on page 32 where the problem is for the vertically collapsed one? Where do I look for the cut-off on the one with bad blue? Any help would be greatly appreciated. It's literally been 10+ years since I've looked at block diagrams and am a bit lost.

If you want to adjust the Blue Gain (B GAIN)and the Blue cut (B C/O)off you can do that with these pots on the B board (pic is from P23 of the manual) - I need to set a realistic expectation, it's hugely unlikley that these have been set incorrectly - that tube is dying, cranking the gain and reducing the cutoff will give it some more time, but it's not going to be a long term fix.



the D board (the deflection board) is home to the vertical deflection circuit, so if you want to fix your vertical colapse this is the place to start. I'd be looking at IC502 first and the surrounding passives.



I think a good way forward could be to swap the D boards over - that will leave you with one fully working 9044, and one 9044 with bad deflection AND a bad tube

 

[Joko3]

@hatmoose Thank you for the advice. What should my main safety concerns be while swapping the boards? Is there any particular step where anything needs to be discharged or is this just a matter of unplugging stuff and plugging back in? Definitely don't want to do anything careless and want to ensure I'm going in with the right info.

Pics added: The page that shows D-board removal (they make it look so easy lol) and then pics of the unit open. This is the one with screen collapse.

 

[hatmoose]

It's a good idea to discharge the CRT if you are going anywhere the anode (that big suction cup attached to the tube)

But for this operation we can probably skip that part - just dont go poking at it.

1) unplug from the power and leave it unpugged overnight
2) flop out that D board as shown in the manual - from memory there are a couple of grounding straps you may have to detach
3) unscrew the D board, unplug all the plugs (take some photos so you know where to plug them back in) and remove
4) perform the same operation on the other unit
5) Swap them over
6) reinstall by perfoming (3) and (2) in reverse

I've got a 9040 somewhere, I can make a short video if you want; I warn you in advance that my video skills are of at least the same standard as my photography skills

 

[Joko3]

@hatmoose

A video would be SUPER helpful actually and would be greatly appreciated. The service manual leaves quite a lot to be desired on removing the board.

I’ll take lots of pics when I do the swap as well. Between your video and the pics I take this repair will be well documented for anyone else in the future.

In exchange for your time I can offer you 2550 yen credit (1.5hr time) for my third party Japan shopping service so you can buy something cool from Japan later .

 

[Joko3]

So I couldn't help myself and ended up swapping the boards out today. There was one difference between them, one had a four prong plug and another had a 5 in the same place, the 5th being a 4:3/16:9 that the other didn't have. Turns out one monitor is a PVM-9044 and the other PVM-9044/2. Anyway, I didn't notice until it was time to plug in that final plug, so I just plugged the five into the four (without plugging in the 16:9). Powered up, and I know have picture.

Now that bad part, the screen is burned in pretty bad. Also the colors are very washed out no matter what you do with the settings. The CPS2 color test looks fine, but then when you actually load the game it looks like bad. Same for S-Video, Shenmue looks especially washed out and void of life. The 250 line PVM 904(1?) I have by comparison is very vibrant. I also owned one of these 9044Q back when I Iived in California, so I have a reference point of what it's supposed to look like. I don't know if it's because that 4:3/16:9 wire couldn't be plugged in, but I doubt it. Either way the tube is too burnt on this thing. It's not too noticeable in the pictures, but believe me you sure as heck see it in person.

At this point, I'm just going to get rid of these things and call it a day. My 250 line has perfect colors and no burn-in, so I'll just stick with that until I can locate a monitor for sale that I can actually go look at in person before buying it.

I'll upload photos of the monitor working on my phone in a bit. Unfortunately, the pictures don't really show just how bad the burn-in is and how washed out the colors really are (it actually looks somewhat fine in the photos lol).

Thank you everyone for your help with this : )

 

[Joko3]

For giggles I put the other D board into the one with the dying tube too. Now that one is vertically collapsed (big surprise lol).

I may try swapping the D-boards back over and then messing with that blue gain and cutoff (gain up, cutoff down right?). The tube definitely looks like it was dying, but at least it wasn't burned in like the one that was originally vertically collapsed. In any case, I'll wait two days to mess with them again as they were both just energized.

 

[Joko3]

Here is the 450 line with burns and super faded color. It looks fine in these pics I know, but trust me it looks like ass in person.

 

[Joko3]

Here is the 250 line I have that is working perfect in comparison. Again pictures don’t fully illustrate the difference, but with the Shenmue shot anyway you can clearly see the difference.

 

[nem]

Surveillance monitors are the worst. Those always have a crap load of hours on them since they're on 24/7.

 

[Joko3]

Surveillance monitors are the worst. Those always have a crap load of hours on them since they're on 24/7.

I guess I got lucky with this 250 line one then. I give up on buying a clean 9” HR model. Getting burned twice in a row stings.

 

[kikaso]

Bummer