HP 2159m Dead, no power

[Mr Bill]

I have a Hp 2159M that is completely dead. I pulled it apart and the 4A fuse is blown. I don't see any scorch/burn marks at all. The power supply has some lelon caps and some united chemcon caps.

The lelon caps are RZW series
The united chemcon caps are KY series except for the big cap which is W series.

I know the lelon caps don't have the best reputation but should i replace the fuse and see what happens or change out the lelon caps along with the fuse?

Its tempting to just put in a new fuse but i am unsure if a dried up cap could cause a fuse to blow. I don't have any background on this monitor like if it endured a lightning storm.

Thanks

[retiredcaps]

Re: HP 2159m Dead, no power

Its tempting to just put in a new fuse but i am unsure if a dried up cap could cause a fuse to blow.

The likely causes for a fuse to become open are:

1) bridge rectifier (long black rectangular component - just above the big cap as per your picture) is shorted
2) power mosfet (Q801) is shorted

If both those components are okay, then replace the fuse and apply power.

PS. Except for the flash, those are great focused clear pictures.

[Mr Bill]

Re: HP 2159m Dead, no power

The likely causes for a fuse to become open are:

1) bridge rectifier (long black rectangular component - just above the big cap as per your picture) is shorted
2) power mosfet (Q801) is shorted

If both those components are okay, then replace the fuse and apply power.

The mosfet (Q801) is shorted

S1-G1 "0L"
S1-D1 "0L"
G1-D1 ".687 Mohm"

PS. Except for the flash, those are great focused clear pictures.

My wife loves this camera better than the new Nikon we got this last summer. Its a Panasonic Lumix

[PlainBill]

Re: HP 2159m Dead, no power

The mosfet (Q801) is shorted

S1-G1 "0L"
S1-D1 "0L"
G1-D1 ".687 Mohm"



My wife loves this camera better than the new Nikon we got this last summer. Its a Panasonic Lumix

What range did you set the DMM to? Those readings indicate Q801 is not shorted. 'OL' would indicate it was out of range, while .687 Mohm implies 687Kohm, certainly reasonable given the drive circuitry.

Testing by inserting a new fuse and seeing if it blows is not a good method of troubleshooting. I use a Variac (variable transformer) and monitor the current as I increase the voltage slowly. An alternate method is to wire a 60 to 100 watt incandescent light bulb in place of the fuse. If the bulb glows at full brightness, there is a problem. If it lights up only briefly and the power supply is putting out normal voltages, it's safe to put in a new fuse.

PlainBill

[retiredcaps]

Re: HP 2159m Dead, no power

The mosfet (Q801) is shorted

S1-G1 "0L"
S1-D1 "0L"
G1-D1 ".687 Mohm"

I know you probably made a typo and meant "not shorted". What about the bridge rectifier?

[Mr Bill]

Re: HP 2159m Dead, no power

What range did you set the DMM to? Those readings indicate Q801 is not shorted. 'OL' would indicate it was out of range, while .687 Mohm implies 687Kohm, certainly reasonable given the drive circuitry.

oops
3:45 a.m. i guess the coffee hadn't kicked in yet.

The bridge is testing good also

1-2 .523 volts
2-1 OL

2-3 OL
3-2 OL

3-4 .520 volts
4-3 OL

Testing by inserting a new fuse and seeing if it blows is not a good method of troubleshooting. I use a Variac (variable transformer) and monitor the current as I increase the voltage slowly. An alternate method is to wire a 60 to 100 watt incandescent light bulb in place of the fuse. If the bulb glows at full brightness, there is a problem. If it lights up only briefly and the power supply is putting out normal voltages, it's safe to put in a new fuse.

Where would the best place to check the voltage if the bulb only lights up briefly? P851 connecter, the power mosfet, large cap?

Thanks

[PlainBill]

Re: HP 2159m Dead, no power

oops
3:45 a.m. i guess the coffee hadn't kicked in yet.

The bridge is testing good also

1-2 .523 volts
2-1 OL

2-3 OL
3-2 OL

3-4 .520 volts
4-3 OL



Where would the best place to check the voltage if the bulb only lights up briefly? P851 connecter, the power mosfet, large cap?

Thanks

I'd do this with the signal card disconnected. Test the voltage across the large cap (should be 1.4 x line voltage - 165 volts in North America), and at the output connector to the signal card. If those test out, put in the fuse, retest, then it's time to hook everything together and see if the monitor works.

PlainBill

[retiredcaps]

Re: HP 2159m Dead, no power

I pulled it apart and the 4A fuse is blown.

Just to confirm, is this fuse F801 right next to the AC plug?

[Mr Bill]

Re: HP 2159m Dead, no power

Just to confirm, is this fuse F801 right next to the AC plug?

Correct

[Mr Bill]

Re: HP 2159m Dead, no power

I'd do this with the signal card disconnected. Test the voltage across the large cap (should be 1.4 x line voltage - 165 volts in North America), and at the output connector to the signal card. If those test out, put in the fuse, retest, then it's time to hook everything together and see if the monitor works.

PlainBill

I used a 60 watt light bulb. Hooked it all up and the bulb doesn't light up at all. I'm only getting 58.2 volts dc at the large cap. Checked the connector and i'm getting in the range of .385-.511 volts dc. I had to run the signal card becuase the on/off switch runs through it. Does the light bulb need to be grounded?

I took a picture incase i'm doing this wrong.

Thanks

[Mr Bill]

Re: HP 2159m Dead, no power

An alternate method is to wire a 60 to 100 watt incandescent light bulb in place of the fuse. If the bulb glows at full brightness, there is a problem. If it lights up only briefly and the power supply is putting out normal voltages, it's safe to put in a new fuse.

PlainBill

Bill,
I grounded the bulb at it lights up full brightness doesn't go off in the 10 seconds that i hold the wire to a ground point.

The monitor doesn't go into standby (amber light) for atleast 30 seconds which seems a bit long since i don't have a video source connected. With the bulb grounded and it lighting up at full brightness i'm still only getting about 59 volts d/c.

Is there anything to check or do you have any thoughts on the bulb lighting up?

Thanks
Bill

[PlainBill]

Re: HP 2159m Dead, no power

You are doing it wrong.

First, a little discussion. This is a standard power supply for a monitor. The supply is on whenever the AC cord is plugged in. There is no need to connect the signal (logic) card, all we're trying to do is see if the power supply comes up without any load. And no, it is not necessary to ground the lamp.

In the setup I described (no signal card connected) I would expect the large cap to show close to 21.4 x line voltage - 120 to 150 volts, and I would expect to see voltage on the output connector. The whole purpose of this test was to see if there was anything drawing excessive current on the primary side of the main transformer.

The results you got indicate it is time to remove the lamp and insert a fuse.

PlainBill

[Mr Bill]

Re: HP 2159m Dead, no power

I think i figured out why i was getting the 59 volts dc at the large cap. I was putting the red probe on the positive on the large cap and the black probe on the ground on the main power connecter.

Doing it the way you explained in the last post i'm getting 163.7 volts dc by using the negative lead on the large cap.

So the next step is to replace the fuse and recheck voltages then put it all together and try it out?

Thanks for the input and sorry for being a "big dummy"

[PlainBill]

Re: HP 2159m Dead, no power

I think i figured out why i was getting the 59 volts dc at the large cap. I was putting the red probe on the positive on the large cap and the black probe on the ground on the main power connecter.

Doing it the way you explained in the last post i'm getting 163.7 volts dc by using the negative lead on the large cap.

So the next step is to replace the fuse and recheck voltages then put it all together and try it out?

Thanks for the input and sorry for being a "big dummy"

AH!!! A common mistake. That hot ground will mislead you every time. Yes, put in the fuse, double check voltages, (but I don't think there will be any problems), and proceed from there.

PlainBill

[ckgbmd]

Re: HP 2159m Dead, no power

Hi, I am wondering if anyone is still checking this thread.

I have the same issue with my 2159m monitor- no power, not even power light. I wont post pics because MrBill already has them at the top of the thread. The 4A fuse seems to be fine, 0.2 Ohm. The MOSFET mentioned above is also fine, high resistances between the source/drain/gate. The bridge rectifier has high resistances (> 250 kOhm) between all four leads, so I guess its not shorted? The caps look OK.

I plug the board in and measured the power output. The are called:

inf
VADJ
On/Off
Grnd
Grnd
+5
+5
1

I pick up the +5 against ground but no other voltages. I think I fogot to measure the "1" and "inf" terminals though because they are hidden. Will have to do tomorrow when I get back to the meter.

Would really appreciate help!

Cos

[Mr Bill]

Re: HP 2159m Dead, no power

Is the power supply the same as the one i have posted in pic #1? I had to scrap the monitor since the panel was deffective but i think i might have the power supply in my box of junk.

[ckgbmd]

Re: HP 2159m Dead, no power

Yes! Everything is exactly the same. I have not figured out if the problem is in the power supply or the other board in the monitor, however. I could definitely make you an offer for the two boards if you were able to dig them up!

I also measured the voltages again, and the only voltages I am getting on the outputs are the +5 V and the Vadj = 0.2 V. I am not reading any voltage on the high voltage outs but that might be the way its supposed to be I am not sure.

[ben7]

Re: HP 2159m Dead, no power

Yes! Everything is exactly the same. I have not figured out if the problem is in the power supply or the other board in the monitor, however. I could definitely make you an offer for the two boards if you were able to dig them up!

I also measured the voltages again, and the only voltages I am getting on the outputs are the +5 V and the Vadj = 0.2 V. I am not reading any voltage on the high voltage outs but that might be the way its supposed to be I am not sure.

The 5v is probably 5v standby.

If you turn the PSU on with the on/off pin on the PSU, it should output all correct voltages. If it does, then your mainboard likely has an issue.

[Mr Bill]

Re: HP 2159m Dead, no power

I found the power supply but i can't find the main board. I think the main board went to e-waste. I usually keep the power boards and strip any usable parts then drop them off for recycling.

I plugged the power supply in and checked what voltages i could and i'm basically getting the same voltages that you posted.

5v - 5v
adj - .2v
and 162v at the large cap.

Your mainboard might be the problem but i don't know. If you want to try it out all i'll ask is the shipping and paypal fees but i'm not holding my breath.

[ckgbmd]

Re: HP 2159m Dead, no power

Thanks! My bank also offers a free check sending service so I could do that too. I will check the voltage across the big cap when I get to work tomorrow.

I am not sure how to use the pin to tun on/off? It would also be good to have some other voltages to check to make sure the PSU is working. I will probably check the button board tomorrow too, since my daughter kept messing with it, and maybe that''s how the trouble started.