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Is it possible to fix old PC monitor

pharaon

Oct 28, 2014
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i want to know if it's possible to fix this old PC monitor

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Minder

Apr 24, 2015
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Looks like some open traces/connections around the HOT (Horizontal output Txfr)!
Has someone been working on it?
M.
 

JWHassler

Dec 22, 2014
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There is an unsoldered(?) terminal in the seventh picture, neat the words "Rev 03"
 

Minder

Apr 24, 2015
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Yeah, that is the ones i referred to;)
M.
 

pharaon

Oct 28, 2014
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Looks like some open traces/connections around the HOT (Horizontal output Txfr)
i know but want to make sure if it's the only problem is there anything else i need to check
 

Minder

Apr 24, 2015
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Well I would re solder the open joints/traces first and see what transpires!
M.
 

kellys_eye

Jun 25, 2010
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I'd power it up and try to explain any ACTUAL fault you have. A set of pictures tells us little/nothing. Is there an actual fault symptom - have you taken any voltage measurements around the board?

The missing trace is an 'obvious' area for concern but, once repaired, may just lead to other problems - fix it and let us know the results.
 

pharaon

Oct 28, 2014
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Is there an actual fault symptom
the power led don't light

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i solider the loses parts, can i test it this way or do i need to reconnect the board to the monitor?
and is there any cautions before testing it
 

Minder

Apr 24, 2015
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Be careful where the end of the CRT HV lead is, for a small B&W monitor it will be around 9kv.
You really need the crt to complete the picture.
Specialized measuring device is required to measure the EHT voltage.
Ensure the ground connection on the crt is connected to the board if testing it out of the case.
M.
 

Minder

Apr 24, 2015
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Apart from the scan coils around the neck of the tube and the cathode socket, there is a HV lead from the HV transformer in question to the connection in the side of the CRT (9kv), there should also be a lead(s) from the board common to the mounting of the CRT and the black (aquadag) coating on the outside of the tube.
It is best to test with everything assembled.
M.
 

73's de Edd

Aug 21, 2015
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Why for . . . . .you no give us Brand and Model number . . .. .so that we can research what pin #1 of LOPT goes to ?
In addition to D10.

And I guesstimate ultor voltage at typically being ~ 1 KVDC per inch of kine screen size.
 
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73's de Edd

Aug 21, 2015
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Sir pharaon . . .


UNISYS techno info ain't easily / readily available . . .especially when they source it out of Korea, from the back door of Hyundai.

REFERENCING:

Your very first photo, with the dominating large BLACK canned main filter capacitor for the AC line supply, being just left of top center.
There is a folded around alum metal heat sink for the HEATSINKING of the POWER FET of the SMPS.
Me thinks that I see a hole where the screw used in mounting it used to be.
Was it someone else . . . . or you . . . . . that pulled that part ?
I think that it might be labeled as Q801 on the board area near it.
Also, is it being fed by a nearby 8 pin mini IC . . . .IC801 . . .with it being a KA3842 ?

ABOVE . . .

I'm just testing to see if I have a like Hyundai schematic . . . . and how many miles per gallon that it gets.

73's de Edd
.....
 

kellys_eye

Jun 25, 2010
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There is a separate SMPS section (identified by the clearance areas of 'no copper' on the underside of the board) that needs to be checked and - if required - repaired first.

I suggest that the OP skill level set is minimal and that, even f the fault could be identified, sourcing and replacing parts would be difficult to say the least.

If we can source the schematic there is a slim chance things could progress......
 

pharaon

Oct 28, 2014
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There is a separate SMPS section (identified by the clearance areas of 'no copper' on the underside of the board) that needs to be checked and - if required - repaired first.
can you show me on the picture
 

pharaon

Oct 28, 2014
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any one know
Q103
"what piece should i get for it"?
 
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