Sorry to ask you guys a computer question again...

[site123a]

That’s why I never buy computer monitors at thrift shops; you’re just getting someone else’s problems… Unless it’s something rare, like the monitor for the Commodore 64.

[ChrisW6ATV]

If you do want to replace it with another Trinitron, I have a 17" Sony monitor in great condition. Never mind that I paid $650 for it new, I will sell it for $65. I probably still have its box, packing materials, and manual as well.

[radiotvnut]

I agree. Picking up these new LCD TV's and monitor's may be good for the back; but, at least I know my '76 19" Zenith color TV is built well since it almost breaks my back to move it.

I have about a four year old HP flat screen CRT monitor that still works fine for the most part. The only problem is the picture is bowed in on the sides when you take the computer out of standby. Turning the monitor off and back on solves the problem. I have no idea who made this monitor for HP; but, I'll continue to use it as long as it works.

That smell you're getting from your CRT board could very well be the result of leaking caps. Just remember to clean off any residue that you may find.

[karmaman]

I've been looking around on Craigslist for a few weeks now, someone gave away a 21" Dell Trinitron FD in "great shape, bright clear picture" a week ago. It broke my heart that it was in central San Diego, about an hour away. No way to get there, I could take the bus, but that would be an all-day excursion that I would have to make on a Saturday, risky and difficult, plus if my parents find out I am S C R E W E D. I'll have to keep checking until something turns up within walking distance.

A friend and I rode our bikes 25 miles to pick up some free computer stuff we found free on Craigslist a few months ago. One of the greatest days of my life. It felt so good when we finally got back, plus we rode through some beautiful scenery on the way there. We scored 2 brand new microphones and three headsets, plus some computer books and an UPS. Good stuff.

I carried the 19" home from the thrift shop, 4 city blocks, told my mom I found it by the side of the road. That was before she flipped and told me no more electronics. I'd be willing to carry a Trinitron from the other side of town if that's what it takes. For now though, I'm going to try and fix this one, and hit up the thrift shops every other day. I don't think she'll make me throw it away if I show up with it.

[Cadillac Kid]

Originally Posted by vinyldavid

Just sneak one home ....I do that often enough with other equipment. ...parents never know.....

David just carries it in on his shoulder and no one notices.

[vinyldavid]

Originally Posted by Cadillac Kid

David just carries it in on his shoulder and no one notices.

[karmaman]

Alright guys, I took a good look at the monitor today. I focused only on the neck board, I will check the chassis tomorrow if necessary. The smell of urine was coming from a 10uf 200V Rubycon cap, on the multimeter it tested 9.6uf, so it's borderline. Most caps seem to test a few uf higher than they are supposed to on my multimeter, this one didn't. It was not leaking or bulged. Maybe this is the cap that was causing the crappy image quality? I also found a resistor on the neck board that measure 10M, according to the service manual it should be 22M. Is it possible that this resistor is what caused the problem? I haven't found any other bad resistors on the neck board, so hopefully I can just change the bad one and swap the cap and I will get a decent picture. The neck board was pretty complicated, I hope I don't have to mess with anything on the rest of the chassis.

[MRX37]

Eh... I would at least test parts on the chassis.

You said the image collapsed to a line. That means something in the horizontal or vertical sections went.

I know on a 21 inch viewsonic I found, the horizontal had collapsed and upon opening it I immediately spotted a fried transistor on the main board.

[karmaman]

I'll test parts on the chassis tomorrow if changing that resistor on the neck board doesn't help, which I have a feeling it won't. I'd rather not mess with the chassis since it looks like it will be a pain the posterior to get the actual pcb out of the metal cage it's in, but every second I have to stare at my backup 17" makes me want to fix that Trinitron more and more. It seems so round (since the Trinitron is vertically flat) and so small.

Also it collapsed into a Vertical line, so no Horizontal deflection.

[karmaman]

Changing the resistor on the neck board had no effect, and Rat Shack didn't have any 10uf 200v capacitors, heading to Fry's tomorrow. What's funny is that the resistor read 150 (incorrect) yesterday, but 220 today (correct). I changed it anyway.

I tackled the chassis today. I found a .2 ohm resistor that reads anywhere from .4 to .7, it fluctuates wildly, and another 2.5M resistor that read .4. I will try swapping these out tomorrow once I buy replacements from Fry's, but I'm losing hope on this monitor. I really doubt those two are the problem, as they were some of the first I tested and they were bad. By the way, I test all of these after removing them from the board, 9/10 times I get funky readings if I don't remove them from the board first.

[MRX37]

I think your horizontal transistor went. If it's anything like the viewsonic I had, it'll be a smallish three pin transistor mounted to a biggish heatsink, and the board around the pins will have darkened significantly.

If you can find no burned spots, your monitor might be savable. Don't give up on it so quickly. Since you obviously like it so much, you'll regret pitching it, epecally if you learn later how you could have fixed it.

[karmaman]

I can't believe I hadn't Googled "sony 420gs". I Google everything and anything, I like to have all my questions answered and the internet does just that. Anyway, found two bits of interesting information. First off, the chassis (D98 according to the service manual) is the same as that in the Dell Trinitron P990. The Dell P990 looks exactly the same, except for the second VGA input on the front. Secondly, I found a forum posting where someone was asking about how much a flyback for one of these puppies cost. However, he also mentioned Q901 and Q902 were replaced in a previous repair. I don't have access to either the monitor or the repair manual right now, but according to google Q901 is a IRFI9634G and Q902 is a FS7KM-18A. They are both 3-pin power regulators. I will try swapping these out. Are they cheap/available at Radio Shack or maybe Fry's (Fry's, for those who don't know, is a huge electronics store, they have 2 rows of electronic components)?

[Eric H]

I have a 17" Trinitron monitor that had bad solder joints, it took a few tries to fix it but I finally did.
That was a few years ago when a CRT monitor was still worth something, I had also bought it new so I didn't want to toss it, now I'd probably just pick up a used one somewhere.

Monitors, especially better monitors with all their boards and shields are a huge pain in the butt to work on!

I just replaced my 21" Sony with an HP LCD 16:9 monitor I got for Christmas (a couple weeks early ) I don't regret it at all as I reclaimed a bunch of desk space and it only weighs maybe 5 lbs compared to the Sony's 68 lbs!

You'd be welcome to the 21" Sony if there was a way to get it to you, it's cosmetically challenged but works well.

[karmaman]

Thanks for the offer Eric, I'll consider it if I can't get my Trinitron going. I guess this is a great monitor because it is a pain to work on. I had to desolder 3 metal cages just to be able to work on the neck board, and there are 5 large heatsinks in there, along with a few small ones for random components. The monitor weighs somewhere around 50-60 pounds. Built like a tank.

So do you guys think any electronics store will carry Q901 and Q902?

[MRX37]

If they don't carry it, order it online. Fry's is your best bet as Radio shack carries mostly phones, and a few electronic components...