I-Inc IF281D Display Problem

[PlainBill]

Re: I-Inc IF281D Display Problem

A lot depends on what the problem actually is. Please define 'shuts itself down'. When you were testing with the Playstation, did the power button stay active (green or blue) or did it go to standby (orange) or off?

Also, what I'd like the same information about this test

i tested the monitor yesterday by turning it on and just leaving it alone for awhile. It went into standby (orange light) and stayed on for hours as long as i didn't try to input a signal in which case it would turn off shortly after.

You could have a bad power supply, bad signal card, bad tcon, etc. Until we know, resoldering what could be the wrong board is pointless.

PlainBill

[AloofOne]

Re: I-Inc IF281D Display Problem

So i was looking over the power board and noticed a cracked solder joint so i decided to attempt a repair.

After about 20 mins practicing on a junk board i felt confident resoldering the joint. After resoldering i powered on the monitor hoping for the best but no change at all. i think they may be more there are alot of questionable spots i see on the board but i'm not the best at spotting them.

So my question is should i resolder any joint i think is suspicion or just leave it alone?

[AloofOne]

Re: I-Inc IF281D Display Problem

ok so i plugged in my playstation as a quick test and it work fine for about 2 mins then shutdown. i used a flashlight on the screen and saw nothing.

here is a photo.

[AloofOne]

Re: I-Inc IF281D Display Problem

Just to clarify when i took the readings i only had the video board and the power board hooked together then powered it on. Did i need to have the whole monitor assembled it order to get the readings?

As far as the light test i will try it today but i know the power light goes off when i try to plug in an input. must be a self shutdown?

Anyways i'll be back shortly with the results.

[jetadm123]

Re: I-Inc IF281D Display Problem

The voltages look good. With a computer connected to the monitor, shine a bright light at an angle against the monitor screen to see if you can see an image.

[AloofOne]

Re: I-Inc IF281D Display Problem

ok here are the results

smaller chip =
2.2Vdc
1.805vdc
3.304vdc

Larger Chip=
2.3vdc
3.304vdc
5.14vdc

I take another photo of the video board so its easier to see.

[jetadm123]

Re: I-Inc IF281D Display Problem

Test 2 using a screw

Rail 1 = 5.14V

Rail 2
Yellow = 0
Orange = 0
Red = 5.14V
Green = 0
Brown = 0
Black = 21.8V

It looks like the power board is outputting 5V and something close to 24V. I suggest connecting the boards back together and measuring the voltage at each pin of the devices circled in the photo.

[AloofOne]

Re: I-Inc IF281D Display Problem

Here you go.

Q1 = 30.01 (resistance)
Q2 = 30.10 (resistance)
Q3 = 31.65 (resistance)
Q4 = 28.35 (resistance)
QS1 = 29.99 2 on that heat sink the other read 000.1 (resistance)
F1 = 000.1-000.2 (fuse) (Resistance)
D10 = 0.610 / 0 (diode test mode)
D8 = 0.423 / 0 (diode test mode)
D5 = 0.617 / 0 (diode test mode)
D7 = 37 - 40 but doesn't look like a diode must be mislabled (resistance)

[AloofOne]

Re: I-Inc IF281D Display Problem

Test 2 using a screw

Rail 1 = 5.14V

Rail 2
Yellow = 0
Orange = 0
Red = 5.14V
Green = 0
Brown = 0
Black = 21.8V

[AloofOne]

Re: I-Inc IF281D Display Problem

i used the black wire from the set as ground. i'll try using a screw. As far as the reading i just copied what i saw from the DMM which has autorange on. do you need me to list which is a resistance test or diode test? i'm not a pro at using this meter. =)

[retiredcaps]

Re: I-Inc IF281D Display Problem

i've also taken some readings on the board prior to your post i hope they help.
Q1 = 30.01
Q2 = 30.10
Q3 = 31.65
Q4 = 28.35
QS1 = 29.99 2 on that heat sink the other read 000.1
F1 = 000.1-000.2 (fuse)
D10 = 0.610 / 0
D8 = 0.423 / 0
D5 = 0.617 / 0
D7 = 37 - 40 but doesn't look like a diode must be mislabled

Hope this helps some.

Regarding the way you are reporting the numbers above. See

https://www.badcaps.net/forum/showpo...2&postcount=31

[retiredcaps]

Re: I-Inc IF281D Display Problem

Rail 2 =
Yellow = -21.7
Orange = -21.7
Red = 5.07
Green = -21.7
Brown = -21.7

If you are getting negative voltages, you are probably using the wrong ground point. Use a screw (like the one by CN4/CN3) on the main board and remeasure.

[AloofOne]

Re: I-Inc IF281D Display Problem

Okay i'm back with more information.

I took some readings from video board with the power plugged in and connected the power board.

Rail 1 = 5.09

Rail 2 =
Yellow = -21.7
Orange = -21.7
Red = 5.07
Green = -21.7
Brown = -21.7

here is a photo of the area i took readings from

[jetadm123]

Re: I-Inc IF281D Display Problem

To measure the voltage off the wiring harnesses, set your meter to DC volts, place your black probe on a good ground point. Each wiring harness is plugged into a connector on the power board with the other end plugged into the inverter, logic board,etc. With your red probe, try measuring the bare wire coming out the back of that connector. Be careful, as those wires look like their close together. If it's easier to get to, then try measuring the voltages from underneath the board.

[AloofOne]

Re: I-Inc IF281D Display Problem

Says on the board. model# FSP217-4F02, DC Output +5.0V -1.5A, +5.0V - 4.35A,+24.0V - 5.5A, +12.0V - 4.77A.

i've also taken some readings on the board prior to your post i hope they help.
Q1 = 30.01
Q2 = 30.10
Q3 = 31.65
Q4 = 28.35
QS1 = 29.99 2 on that heat sink the other read 000.1
F1 = 000.1-000.2 (fuse)
D10 = 0.610 / 0
D8 = 0.423 / 0
D5 = 0.617 / 0
D7 = 37 - 40 but doesn't look like a diode must be mislabled

Hope this helps some.

How do you test the voltage at the wire harness?

[jetadm123]

Re: I-Inc IF281D Display Problem

Well, it appears that the printing on the power board indicates the output voltages are 5v and 24v. Correct? The 24v should feed the inverter and the 5v supplies the video board. I suggest piecing everything back together and measuring for these voltages at the wiring harnesses connected to each board.

[AloofOne]

Re: I-Inc IF281D Display Problem

hello again, sorry i haven't replied in some time i was sick last week and haven't been able to do any testing. I was able to borrow a friends DMM of decent quality so i'm hoping my readings with be accurate.

i tested the monitor yesterday by turning it on and just leaving it alone for awhile. It went into standby (orange light) and stayed on for hours as long as i didn't try to input a signal in which case it would turn off shortly after. i noticed that on the video board 1 of the chips (ic controller?) had a solder bridge. Not sure if that has anything to do with my problem. Anyways i checked all the caps and they seem fine in appearance but from reading the forums here i know that they can still be bad.

Any advice from here would be appreciated.

[AloofOne]

Re: I-Inc IF281D Display Problem

thank you, i'll read through the posts.

[retiredcaps]

Re: I-Inc IF281D Display Problem

I turned the monitor back on again and this time it shut down in about 20secs, a third time and it shut down almost immediately.

You might be experiencing 2 seconds to black. Read through posts #19 and #20 at

https://www.badcaps.net/forum/showthread.php?t=10419

2 seconds to black can be (in no particular order)

a) bad caps
b) bad inverter transformer
c) bad ccfls
d) bad ccfl wiring (especially the return wire)

[AloofOne]

Re: I-Inc IF281D Display Problem

i removed the inverter board from the monitor but it has some plastic cover over which is very difficult to remove.