IBM Thinkvision 6736-HC9 No power

[budm]

Re: IBM Thinkvision 6736-HC9 No power

Or just do resistance reading from the L on the IEC inlet all the way to the ~of the bridge, same for the N on the IEC inlet all the way to the ~ of the bridge.

[eckertb83]

Re: IBM Thinkvision 6736-HC9 No power

OK I tested just to 2 points on the bridge rectifier ( between + and -) and I dont get any reading at all.

Didnt see your post budm, I did check resistance between those 2 points

Live resistance 10.0

Netural resistance 1.6

[Davi.p]

Re: IBM Thinkvision 6736-HC9 No power

"OK I tested just to 2 points on the bridge rectifier ..." i don't understand, tested how, voltage, ohm? between which points?

"Live resistance 10.0
Netural resistance 1.6"

ohm? Megaohm??

[budm]

Re: IBM Thinkvision 6736-HC9 No power

"Live resistance 10.0

Netural resistance 1.6"

I hope those are in Ohm, if that is the case you may be OK. The Neutral to ~ of the bridge is good.
The Line to ~ of the bridge is 10 Ohms is due to the Thermistor (I do not know the value, you need to look at it) is may or may not be OK, but since we do not have open circuit between Line or Neutral to the ~of the bridge, then you should be able to see 120VAC on the two ~ pins of the bridge at this point.

[eckertb83]

Re: IBM Thinkvision 6736-HC9 No power

yes that's ohms, I had the DMM set to 200. I flipped the board over to look for the Thermistor (TH) I couldn't locate. Where about should it be?

[budm]

Re: IBM Thinkvision 6736-HC9 No power

Thermistor. So at this point, do you get 120VAC at the ~ pins?

[eckertb83]

Re: IBM Thinkvision 6736-HC9 No power

I removed the heat shrink wrap from the thermistor and this is what is printed on it-
SCK
086

I am getting about 117VAC at the ~ pins. It jumps around a little but not much 116.8-117.4 VAC

[budm]

Re: IBM Thinkvision 6736-HC9 No power

"I am getting about 117VAC at the ~ pins. It jumps around a little but not much 116.8-117.4 VAC" Then you should have DC on those two min filter caps, not 0V as you had tested before.

[eckertb83]

Re: IBM Thinkvision 6736-HC9 No power

Yes I am getting between 159 and 162 DCV on the 2 filter caps. I'm not positive but I may have had the switch in the wrong position the first time I tested them.

[budm]

Re: IBM Thinkvision 6736-HC9 No power

OK, that was a long tail chasing to get to this point, we now need the P/N of that SMPS IC so we can start check voltages. You also try heating up the two small caps next to the S shape heat sink where the MOSFET is mounted on to see if the power supply will start up.

[eckertb83]

Re: IBM Thinkvision 6736-HC9 No power

IC-
203D6
PTFP

I will try to heat them up with my heat gun and report back.

[budm]

Re: IBM Thinkvision 6736-HC9 No power

That numbering system does not look right, is it 1203?
https://cdn.badcaps-static.com/pdfs/...93618ef001.pdf
If it is, then check the resistance between GND PIN 4 against 7 other pins and report the resistance readings, make sure to put down if the resistances are in Ohms, K Ohms, or M Ohms. No power to the board, of course.

[Davi.p]

Re: IBM Thinkvision 6736-HC9 No power

eckert please, you confirm the main mosfet measurement that last time seemed shorted?

[selldoor]

Re: IBM Thinkvision 6736-HC9 No power

I will try to heat them up with my heat gun and report back.

"Heat" means quite gentle as with a hairdryer for 30 seconds. you are not trying to reflow them.

[eckertb83]

Re: IBM Thinkvision 6736-HC9 No power

I am trying to measure resistance but cant seem to get any thing. There was some sorta glue that I had to clean off before I could actually do anything. I had the DMM set at 200 Ohms and couldn't get any reading off any of the pins. Does this mean its shorted?

"You also try heating up the two small caps next to the S shape heat sink where the MOSFET is mounted on to see if the power supply will start up."

Do I have to connect it back to the video board and heat it up then try to turn it on?

[budm]

Re: IBM Thinkvision 6736-HC9 No power

Just that board by itself, then see if you do get any 5V and other voltages on the pins going to the logic board.

[selldoor]

Re: IBM Thinkvision 6736-HC9 No power

I am trying to measure resistance but cant seem to get any thing. There was some sorta glue that I had to clean off before I could actually do anything. I had the DMM set at 200 Ohms and couldn't get any reading off any of the pins. Does this mean its shorted?
?

Which query are you replying to? what are you testing? try cleaning your probes with Isopropyl alcohol - shorted is the same as holding your probes together or very low ohms.

Please read back through and answer some of the questions you have missed.
Please update you profile with country so we know which time zone you are in
and voltage .

[eckertb83]

Re: IBM Thinkvision 6736-HC9 No power

SMPS IC is what I'm testing, that I cant get any reading like its shorted. I have cleaned the probes and still the same thing. I posted a pic of the IC so you can see the part number. I believe the data sheet Budm posted is correct for this part.

I still have to try heating it up and checking it for voltage.

as far as the MOSFET i did re-test it still shows as being shorted.
DMM set @ 200 Ohms
blk probe
pin1- pin2=1
1-3=1
2-3=1
all on the left side of the DMM

I changed the setting on the DMM to 2000K ohms and I am getting somewhere i hope....

all done with back probe on PIN 4 Ground.
1-004
2-046
3-001
5-002
6-329
PIN 7&8 just a 1 one the left no resistance.

[selldoor]

Re: IBM Thinkvision 6736-HC9 No power

We keep asking you to say what the value of the results are do you mean 1 ohm

I do wonder if the "1" you are stating is in fact the meter telling you it is over scale
The same as having your meter on ohms 200 and the probes apart?

If that is the case the mosfet is probably NOT shorted

[eckertb83]

Re: IBM Thinkvision 6736-HC9 No power

Yes that is what I mean, That is also why I stated it was on the left of the meter.
Reading through the "2sec to black guide" I remember reading that when checking resistance use 200Ohm setting for most/all parts. Even the other monitor that DID have a bad MOSFET and Bridge I tested them with 200Ohm setting .