Daytek F19AH

[retiredcaps]

Re: Daytek F19AH

A few different views.

Holy. The very first monitor I repaired was coated in that dust like yours. It took more than 30 minutes just to clean up the insides to a respectable point.

I didn't think Winnipeg was that dusty!

[UserName666]

Re: Daytek F19AH

There was no smoke just a faint burn smell at the time it went out/died.

[PlainBill]

Re: Daytek F19AH

Yes, go ahead and put D108 back. Can you supply a photo of the logic board (board that that plugs in the 6 prong connector on the power board)?

Man, at this point I'm hoping that PlainBill may have a trick up his sleeve.

At this point PlainBill is trying to find a rational explanation for the behavior of the output. Why is voltage detected at the input side of the opto-isolator, but not at the output? And what is the expected output voltage? Where did teh 'magic smoke' come from (or is that another monitor)?

PlainBill

[UserName666]

Re: Daytek F19AH

A few different views.

[jetadm123]

Re: Daytek F19AH

Yes, go ahead and put D108 back. Can you supply a photo of the logic board (board that that plugs in the 6 prong connector on the power board)?

Man, at this point I'm hoping that PlainBill may have a trick up his sleeve.

[retiredcaps]

Re: Daytek F19AH

So if D108 is good it can be put back in?

jetadm123 asked for these readings so wait to see if jetadm123 is satisifed first.

[UserName666]

Re: Daytek F19AH

So if D108 is good it can be put back in?

[retiredcaps]

Re: Daytek F19AH

I'm not sure what it is but it is labeled L102. D108 is what I just took out.

This boards also has an L107,L105 and L108 surrounding the Filter cap. Not that has anything to do with anything. Just not sure what the "L" is.

L indicates an inductor. They will measure 0.3 ohms on the multimeter. L102 is in parallel with D108 pins 1-3 (look at the back of the PCB). This explains why D108 was reading 0.3 ohms suggesting it is shorted.

This is why sometimes, "in circuit" testing, is not reliable. We know D108 is good out of circuit.

PS. Good job on the pics. It helps a lot.

[UserName666]

Re: Daytek F19AH

I'm not sure what it is but it is labeled L102. D108 is what I just took out.

This boards also has an L107,L105 and L108 surrounding the Filter cap. Not that has anything to do with anything. Just not sure what the "L" is.

[retiredcaps]

Re: Daytek F19AH

OK I pulled the STPS10H100CT from the board and it reads:

There is another component right by this STPS10H100CT. I can't see it from the angle of the pictures, but it has 02 and the end. I think it is a diode D102?

1) what is it?
2) if it is a diode, do a diode check with your multimeter. This component could be shorted? This would explain why pin 1-3 on the STPS10H100CT in circuit, but measure non shorted out of circuit.

STPS10H100CT is good out of circuit from your measurements.

[UserName666]

Re: Daytek F19AH

OK I pulled the STPS10H100CT from the board and it reads:

1-2 = Starts at 30 Mohm and continuously drops rapidly-reverse leads- Starts at 32 Kohm and drops slowly.

1-3 = Starts at 26 Mohm and drops rapidly -reverse leads- Starts at 36Mohm and drops rapidly

2-3 = Starts at 30 Mohm and drops rapidly -reverse leads- 40.1 Kohm (steady)

[retiredcaps]

Re: Daytek F19AH

No I meant 2mm close on the top of the board but looking underneath the middle pin of the rectifier IS connected to the cap that was bloated.

Rectifier in blue and the capacitor that bloated is in red.

Okay, soldering all looks good. No bridges. I suggest you desolder the component and test out of circuit.

If it is bad, a replacement is available at digikey for just over $1.

[UserName666]

Re: Daytek F19AH

No I meant 2mm close on the top of the board but looking underneath the middle pin of the rectifier IS connected to the cap that was bloated.

Rectifier in blue and the capacitor that bloated is in red.

[retiredcaps]

Re: Daytek F19AH

OK & ya know what...The one with 00.3 ohm reading (red) is DIRECTLY BESIDE the capacitor that was bloated by like less than 2mm. I'll get to the desoldering in a little bit and get back w/ he readings

Is it possible that your replacement capacitor soldering is touching this component? That would cause false readings.

[UserName666]

Re: Daytek F19AH

0.3 and 27 ohms suggests this is shorted or bad.

edit: Datasheet is at



You will have to desolder this component and test out of circuit to verify it is shorted.

F, I think, is Fairchild.

OK & ya know what...The one with 00.3 ohm reading (red) is DIRECTLY BESIDE the capacitor that was bloated by like less than 2mm. I'll get to the desoldering in a little bit and get back w/ he readings

[retiredcaps]

Re: Daytek F19AH

The one circled in RED by the cluster of caps is:
1-2 = 27.1 ohms reverse leads 26 ohms
1-3 = 00.3 ohms reverse leads 00.3 ohms
2-3 = 27.1 ohms reverse leads 26 ohms

Part #'s are visible in pic 2 & 3. I didn't know if that was a letter F or a company logo.

0.3 and 27 ohms suggests this is shorted or bad.

edit: Datasheet is at



You will have to desolder this component and test out of circuit to verify it is shorted.

F, I think, is Fairchild.

[UserName666]

Re: Daytek F19AH

As for the service manual I found one for a 1914 but not 1914bm specific. The powerboard is not a match.

[UserName666]

Re: Daytek F19AH

I should have asked first but I hope these tests can be done in-board because thats the way I did it.

The one circled in YELLOW on the heatsink by the filter cap is:
1-2 = Starts at 41 Kohm rises to about 400 Kohm then jumps to about 1.2 Mohm and keeps rising. Reverse leads 0 Mohms
1-3 = 86.1 kohm reverse leads 81.2 Kohm
2-3 Starts at 18.5 Mohms and drops. I stopped testing at 12 Mohms. Reverse leads 0 Mohms

The one circled in RED by the cluster of caps is:
1-2 = 27.1 ohms reverse leads 26 ohms
1-3 = 00.3 ohms reverse leads 00.3 ohms
2-3 = 27.1 ohms reverse leads 26 ohms

Part #'s are visible in pic 2 & 3. I didn't know if that was a letter F or a company logo.

[jetadm123]

Re: Daytek F19AH

This is sort of a weird design where there's only one dual diode pak (Q1 in the pdf file) that supplies 12 volts for everything. Normally, you have two separate paks, one to supply 12V to the inverter and the other to supply 5V to the logic board and LCD panel. Looking at your photo, I believe the diode pak on your board is the one mounted to the heatsink at the left. It usually has a symbol of two diodes connected head to head stamped on it. Please supply the part # and with power off try performing a short circuit check on it in circuit.

[retiredcaps]

Re: Daytek F19AH

There is a possiblity that acer 1914bm uses the same power board as this Daytek. You can search acer 1914bm service manual to see if there is one with schematics.

I got this idea from the 0509d1248 designation (right above the li shin) on the board.