Dell P1110 21" CRT repair thread

[laser]

Re: Dell P1110 21" CRT repair thread

ok I done a video of this monitor starting cold, no crackling or flashes this time
( sometimes it does not make)
as you can see the black is tinted in green, is out of brightness but this can't be noted very well in the video

I was exaggerating about taking 1 hour to full stabilize in good colors and normal brightness, it takes around 20-25 mins, I controlled using a clock

also another wrong thing I said is the monitor is based on the sony G500, according to the specs it seems is a sony G520
Tomorrow I will make the IC406 mod and I will use windas to normalize G2 to a normal level if is required ,and I will upload a new video starting in cold

https://youtu.be/ndTqymJUZVc

[momaka]

Re: Dell P1110 21" CRT repair thread

thanks for your reply master

about the "big flash and cracking"... what the hell this could be,?a bad weld ?
the flyback? an aged cap?

It's the high G2 causing it. I don't know why, though. Most likely there is a protection circuit that kicks in due to the abnormally-high G2 causing other issues.

On my Dell D1626HT, it was a different type of "cracking" - more of a static discharge, actually. And it would happen randomly, regardless if the monitor was warm due to hours of use or cold. Even have a thread for it here:
https://www.badcaps.net/forum/showth...hlight=d1626ht

I looked at the G board quicly and I don't noted any inflated cap

These Sony monitors run cool and they have good quality Japanese caps inside (Nichicon, United Chemicon, and Rubycon), so unlikely that you will see any bad caps.

I will upload a video later showing my monitor starting cold before I make the IC 406 mod, then of course I will make a new video with the mod done to see the differences

Sounds good. Keep us updated.

if flashes and cracking still persist I will dismantle the G board to look around where is the problem, I'm almost sure the problem is located there

Again, I doubt the G board is the problem.
However, it is a good idea to inspect the solder joints around all regulators and large parts. One of my Sony GDM-FW900 monitors had cracked joints on the stand-by regulator and heater regulator. It made the monitor hang in stand-by mode all the time (a signal would not wake up the monitor at all). Once I re-soldered those joints, it started working correctly.

ok I done a video of this monitor starting cold, no crackling or flashes this time
( sometimes it does not make)
as you can see the black is tinted in green, is out of brightness but this can't be noted very well in the video

Yes, I can see the green tint quite well. Classic G2-overbright issue, indeed. Do the IC406 pin mod and see if the monitor does the crackling and flashes again.

I was exaggerating about taking 1 hour to full stabilize in good colors and normal brightness, it takes around 20-25 mins, I controlled using a clock

Same for my Sony E540.

also another wrong thing I said is the monitor is based on the sony G500, according to the specs it seems is a sony G520

Oh no!
Externally, that looks the same as my Sony E540, too. And according to the E540 service manual schematics, IC 406 is already grounded :\ . Check your A board and see if that is the case. If yes, then we have the same monitor. What's worse is that I noticed yesterday that my E540 is also starting to develop an G2 overbright issue. Not sure how to permanently fix this one if there is no "Drift Correction" circuit to disable. Perhaps WinDAS to adjust the G2 only? Let me know what you find with yours. Maybe I will pull and disassemble mine as well so we can compare.

[blizzak]

Re: Dell P1110 21" CRT repair thread

Bump from another dimension (6.5 years since last post on this thread), hope this is OK as opposed to starting a new thread! Also seems I can't post new threads right now anyways...

I have a Dell P1130 that won't turn on at all. It was having some issues for a while but I wasn't sure if they were software or hardware, was using a DP to VGA adapter. Sometimes on starting PC the monitor would not display image or turn on (orange light showing), though the PC thought it was outputting to it. If I disabled the monitor in Windows and reconnected it would come back. Colours were not perfect but after warming up it seemed OK, did some tweaks but nothing crazy.

Fast forward to the other day when I was printing off some things for a friend and printer runs out of paper (older beast of a Brother laser MFC); connected to the same circuit as this monitor (note: never do this). Apparently the Brother was doing some mean things to the circuit while waiting for paper (seemed like constantly cycling fuser on and off maybe) and was in this state for a while. Come back and the P1130 won't turn on at all, no lights.

I find the post below from Th3_uN1Qu3:

Start by checking the mains fuse. If the fuse is blown, check the main switching transistor, it probably failed shorted. It doesn't go on its own - so check the capacitors too, one or more could be bad.

If the fuse isn't blown and the transistor looks fine check the controller IC in the power supply. Btw, if the main supply runs but seems to be in protection mode (listen for a ticking noise), check the HOT (horizontal output transistor). That is by far the most common part to fail in CRT monitors.

The service manual is pretty easy to locate and the schematics are very detailed so troubleshooting should be straightforward. If you can't find it i'll upload it here. Edit: This is it: http://www.eserviceinfo.com/download..._CPD-E500.html

So I open up the monitor, check fuse and it's blown. Order more fuses, replace fuse and on attempting to power up monitor again it blows. Suspect the main switching transistor per the above post. Try to look at the service manual but haven't analyzed circuit diagrams in a long time:
https://www.manualslib.com/manual/72...ron-P1130.html

No evidence of swollen caps, nothing obvious on the boards from a bird's eye view. If anyone has any suggestions let me know, if I get into it and make any headway will post here.

[Per Hansson]

Re: Dell P1110 21" CRT repair thread

On PDF page 7 you have the mains input on the left.
Just measure between live and neutral with your multimeter with a new fuse in the monitor.
Since it blows as you plug it in I expect a really low resistance reading.
Now start looking further into the monitor (referring to the schematic here)
Follow the path and test each component, the one with the lowest resistance will be the shorted one.
You can also of course take out components until the short is no more.
A good start is the bridge rectifier, then Q640/Q641

[R_J]

Re: Dell P1110 21" CRT repair thread

Does the fuse blow as soon as it is plugged in or do you need to press the power button and then it blows?
If it blows as soon as it is plugged in, suspect VDR601 is shorted. Next could be the bridge rectifier, I don't suspect the mosfets that are bad as there is a fuse resistor in the supply to them (R620, 0.1Ω), I also don't suspect IC601 as it should blow R610 & R611 if it's internal mosfet was shorted.