Re: I-Inc IF281D Display Problem
Thank you retired caps
The replacement power supply has a problem, +5v is not there, +5sb +12 and +24 are working OK, attached pic of PS, any suggestions would be helpful....
DIODE
Member
Last Activity: 08-08-2012, 02:08 PM
Joined: 03-08-2012
Location: Etobicke, Ontario
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Re: I-Inc IF281D Display Problem
HELLO
I have a I-INC 28 lcd monitor IF281D that was dead and after replacing the power supply it now powers up fine but will not display any image. The symptoms are as follows;
Without VGA input connected the power on light comes on blue the sceen illuminates white with no image and then goes black after a few seconds and the power light turns amble.
With a VGA signal connected the same thing occures but the screen stays illuminated white with no image and power on light remains blue until power is removed....Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
I cannot be certain about the LED operation for that model. However, if the power supply is labled "PHIHONG model PSM217-404-H-R" The following applies
On the header connection is printed in very small white lettering Gnd, 5v, 5vsb, PS-on,12v and 24v. If PS-ON is between 3.3 and 5.2 volts the other voltages should be present if theye are not the problem is on the Power supply. If PS-On is below 3.3 the power supply is not getting a power up signal from the main board.Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
Whne the monitor is plugged in and the LED goes blue then amber the monitor is powered up but not detecting an input or the main board that takes the input has a problem. As a first step connect video to a different input, HDMI input or the VGA input to illiminate lack of input as the problem. If the video souces is confirmed and tried on both inputs and still no blue led I suspect the main board not recognizing the video input(main board= board with VGA/HDMI connectors) This is based on my knowledge og the I-INC IF281D monitor that is likely...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
If anyone has a schematic of this power supply or very similar power supply I would appreciate knowing, the power supply is "PHIHONG model PSM217-404-H-R , the monitor model is; I-INC IF281D , similar to HANSPREE 281D.
I appreciatte all help and assitance. Thank You...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
The transformer is in place and all pins are soldered, See post 214 - the transformer was removed and reinstalled, the post 214 picture of the foil side was used to ilustrate what voltages are present at PS-ON after reinstalling the transformer, the post 214 pics are the best focus and exposures of the foil side I have....Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
I tried a 3.3k jumper from PS-ON to 5vsb and still no 5/12/24 volts, I measured no AC voltage going to the primary winding of the xformer in the center of the board. See attached pdf pic with voltages with 3.3k jumper from PS-ON to 5vsb, the 4.89v shown is the voltage measured on the PS-ON circuit with 3.3k jumper PS- to 5vsb. The PS-ON signal connects to Q702 and it appears to function. 174VDC is measured across the large cap downstream from the 120vac bridge rectifier.
Any suggestions would be helpful, thank you for...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
Jasgriff See post 207, the top left is temp 3A fuse wire....Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
Is it likely to cause damage to jumper the PS-ON to the 5vsb?...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
The pin maked PS-ON on the connector that goes to the main board (black wire end of header) toggles between 0v with amber led(input not detected) and 3.169v with blue led(input detected).Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
I tested the PS connected to the rest of the monitor components and removed but always connected to the main board, the main board needed to turn on the 5/12/24v supplies. I have attached pics of the PS with and without transformer, I removed the xformer to inspect its underside as I thought I saw/heard a click/pop from its underside....Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
Attached location of C114 , for some reason teaxt not does not showing on jpg...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
The Standby 5vsb is now working and the the blue power on and amber standby led on monitor front indictes power and recognize when video is connected - toggles front blue to amber as it should. Attached is location of slightly under value cap C114 -labled 2.2 uf measured 1.7, see attached pic showing location. The 5vsb is a rock steady 5.1v
The problem now is there is no image showing , ther is no 5v or 12 v or 24v on the labled output terminals of the PS.
I suspect this problem originates from the blown trace/fuse...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
I tested using Sinometer 6013 Capacitance meter pic attached, while observing polarity I measured in circuit cap values and if I could not read the minimum value I would remove, test and reinstall. I normally do not get into board level diagnosis (as pervious post,-blown fuse/bridge might attest - embarrassing). After thinking about this I am puzzled that the caps totaling about 1300 uf measured at the PS 5vsb terminal does not hold the 5vsb steady , when I measured only 40ma current draw, wondering if there is a ringing/resonance going on...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
I tested voltage between ground pin1, and Vcc pin 2, on SMPS DM0265R , it reads a jittery 10.56v to 11.32v as recorded on Fluke 85. I tested all caps suggested on page 1 and 2 of this thread as suggested by budm in post 197 ,all tested OK. Had to replace the bridge, 120vac fuse and about 2 inches of trace on the PS, a naughty ground clip from the scope poped off, went where it should'nt, sounded like a little red, firecraker. I measured the jittery 10.56v to 11.32v on the SMPS gnd/Vcc before the accident, all appears to be as it was now....Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
That ulr points to a FS DMO365R data sheet, page says 265 but the printed data sheet lists 365, looks quite similar to the attached DMO264R.
Dan...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
Confirming DM0265R, scraped some of the paint off pic attached, I will do those checks
Thank you very much budm/retiredcaps
Dan...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
So after exhausting all the other tests I dusted off the scope and found intermitant/flaky AC power going to D701 Anode, Attached pics (sorry about the quality). The AC supply frequency to D701 is varying between 4 K Hz and 9 K Hz going low to high on at about 45ms intervals (based on frequency counter - Fluke 85 and looking at the DC waveform) I could not sync the scope to clearly see the AC faveform attache pic as good as it gets - "AC Voltage....
The DC that varies from 3.2v to 5v is shown in pic "DC on D701 Cathode,...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
Thanks for those suggestions budm, I was also considering using 3 x 1.5v bateries in series to get the 5vsb up so the 5vmain could be switched on. If I only had a schematic of this I could manully start the 5vmain and jump it through a 1k to 5vsb......
Little guys hockey parctise in 4.5 hrs, I'll post tomorrow thanks again
Dan...Leave a comment:
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Re: Hanns-G HG281D, LCD Monitor no power
I looked at the link re 1 to 3 k resistor connect 5vsb to 5vmain, I will try that but I think the 5vmain is not on until the monitor is turned on and that needs the 5vsb to turn on, I'm thinking I need to pull D701 and test it, I may cut one of it's leads so not to heat it and lose the symptom of defect, D107 is sort of behaving like a diode in series with a 400-1k ohm resistor, if in fact it is an ordinary si power diode.
And thanks for the suggestions
Dan...Leave a comment:
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