F-19GS FUSE Monitor

[davg]

I have two of these monitors both of them will power up and show video however one will show squiggle reddish lines on the screen after 10-15 minutes of use? The other do not have a power light but do have a amber light when in sleep mode. The buttons on the front do no function at all? Both have an external AC/DC power supply. Picture of the boards attached

[retiredcaps]

Re: F-19GS FUSE Monitor

Check the voltage regulator on the main board. See if the DC voltage from the adapter is stable or not. The external adapter could have bad caps inside.

[davg]

Re: F-19GS FUSE Monitor

Thanks retiredcasps have to pull it apart again but in the meantime the voltage from the adapter is stable I have tried a couple different ones and the results were the same.

[selldoor]

Re: F-19GS FUSE Monitor

As you have 2 have you tried pick and mixing the boards to see if symptoms remain the same or if lucky a combination that works

[davg]

Re: F-19GS FUSE Monitor

Thanks selldoor Yes, I have swapped the main board and just transferred the symptoms. Did not swap the inverter boards??

[selldoor]

Re: F-19GS FUSE Monitor

On the mainboard in the picture there is no voltage regulator on U5 does it look like there has been one - is there one on the other board

[davg]

Re: F-19GS FUSE Monitor

No U-5 is empty on th other board as well. Some of the readings on the regulators
U-4
5JCL
17-18L
pin 1-0.24v
pin 2-1.74v
pin 3-5.06v

U-3
5GNL
17-33L
pin 1-0.24
pin 2-3.24
pin 3-5.06

U-1
SDM4435 (not sure)
59468T
pin 1-19.48v
pin 2-19.48
pin 3-19.48
pin 4-15.73
pin 5 to 8 5.12

U-2
FP5001
576-89L (not sure)
pin 1-18.75v
pin 2,3,4-0v
pin 5-.159
pin 6-1.35
pin 7-.926
pin 8-.029
The caps on the board a really compact and I have not replaced them don;t have anything to fit

[davg]

Re: F-19GS FUSE Monitor

These readings were taken on the unit that has video but no button control on the front panel. What components control the menu, on/off, etc buttons?
I think the readings on U1 may be taken wrong? The data sheet if I have the right one list pins 1-3 as source pin 4 gate and pins 5-8 as drain? I am not sure the sequence to take these readings. I can't find a data sheet U2 when I type in FP5001 I get a list of data sheets but all are three pin.

[selldoor]

Re: F-19GS FUSE Monitor

Not sure where we are going with this.
Another think to test would be the secondary windings on the inverter boards.
Power off -Meter on 2000ohms on the sides with 4 pins test the top two then the bottom two on each transformer and post the results.

[davg]

Re: F-19GS FUSE Monitor

Thanks selldoor I am hoping we are going to identify the components causing the problem at least that is the aim? Since this unit is working except for the fact that I can't turn it off and there is no OSM. I was wondering if someone might be able to narrow it down to a particular component or components? So the secondary windings on the inverter board could be a cause? That is the kind of thing I like to know.

[selldoor]

Re: F-19GS FUSE Monitor

Sorry I have re read the thread - may have mixed it up with another. The Inverter Test is not relevant as the backlight comes on and stays on on both machines. If the osm is not coming on and you cant switch it off that sounds like the mainboard or the button board. On the one that comes on then deteriorates does the OSM and buttons work on that?


Also is there another board on the back of the panel- can you post a picture of it - probably need 3 shots to get it all close up.

[davg]

Re: F-19GS FUSE Monitor

On the one that comes on then deteriorates does the OSM and buttons work on that?
Yes it does and I switch the two button boards and no change. so it must be in the main board.
I just blew the crap out of Q9 on the main board to the one that was working but deteriorates?? and it is so small I can't even get a reading on it and that will be quite difficult to take out and put back?? Right now I only have one of these monitors?? Chaulk it up to experience or the lack there of. Edit (The markings on Q9 appears to be t04 (PE)

[davg]

Re: F-19GS FUSE Monitor

How important are the numbers on these small transistors? How can I determine its function? Where can I buy a replacement? I have a board with several on it but the numbers are not the same?

[davg]

Re: F-19GS FUSE Monitor

Hi guys I would like to attempt replacing this Q9 transistor if I could find one (or three) (I know this would be quite a challenge) but I have no idea what I would be looking for?? The only markings on it looks like t04 and PE vertically?? can someone help identify this little component? I have looked but can't seem to find a t04 although Digikey list quite a number transistors with different #? I'm still kicking myself for being so careless??? It is unforgiving so as it have been said so may times in here " be very very careful when taking readings, I am only thankful it was only a board that I smoked?