HP 2509m won't turn on, no power to ON/OFF LED

[withalligators]

Hi guys, I found an HP 2509m in the bin, and would like to try and fix it. The large size and built in speakers seem like it would be good screen for my father.

So I've read up a bunch on this beast, and it seems like one or both mosfets on the daughter board are shot, as well as the accompanying diode, maybe an IC, and maybe a resistor. Also, I'm certain once I get the board working properly, the bulbs will be shot and I'll have to replace those.

I've read through many threads, including:

https://www.badcaps.net/forum/showthread.php?t=24866
https://www.badcaps.net/forum/showth...ighlight=2509m
https://www.badcaps.net/forum/showth...BDG#post117302
http://h30434.www3.hp.com/t5/Desktop...s/td-p/1210387
http://h30434.www3.hp.com/t5/Desktop...D/td-p/1643025

which seem to capture the gist of the problem.

I am comfortable with the component replacement on this tiny board, but unsure of which parts to buy.

The components in question on the board are:
mosfet #1: Nikos P5506BDG N-channel
mosfet #2: Nikos P9006EDG P-channel
Diode: SR26 PJ039
IC: INL816GN AA3113.1N 1016A1
and 105 ohm surface mount resistor

I've read that for the P5506BDG fet, I can use STD20NF06L, FDD8451, or FDB6030L
for the P9006EDG, the only thing I've seen is AOD413
for the diode, I've seen STPS2L60 and SS26, easy enough
No idea about the IC, or if it's even required
and the resistor has 105 on it, so I assume a 105ohm surface mount is what I want, but digikey has so many options that I'm unsure of, like wattage and such.

If requested, I can desolder the caps blocking view of the daughter board and get some pics if it'll help.

Thanks in advance!
Alex

[Davi.p]

Re: HP 2509m won't turn on, no power to ON/OFF LED

but where are the sympthoms??

[withalligators]

Re: HP 2509m won't turn on, no power to ON/OFF LED

Sorry, symptoms are standard 2509m stuff. Seems to have no power. No indicator (on/off LED) power, no response to buttons, etc. There is 165-168 at the big filter cap. Replacing the parts I mentioned earlier is supposed to restore everything to working order except the screen.

I expect once the fets are put in, I'll have a screen that is darkened on the left side.

What I need help with now is identifying the proper replacement #s, preferably from digikey.

Thanks!
Alex

[Davi.p]

Re: HP 2509m won't turn on, no power to ON/OFF LED

sorry i've forgot the symptom was in subject..

[selldoor]

Re: HP 2509m won't turn on, no power to ON/OFF LED

Hi - I was just going to say we dont need to know any symptoms as they are covered in the links you posted and in the heading.
I did do some research in the previous posts and it was hard then, 12 months on I think parts are like hens teeth tho someone has a "hardly used"
monitor on amazon for 150US.

I dont have a lot of time at the moment to help you and as you have seen from the slow response on the other threads, I think it will be hard going.

Easy start - the resistor is unlikely to be 105ohms - I suggest 1Mohm
ie 10 to the power 5

see here
http://www.hobby-hour.com/electronics/smdcalc.php.

Scroll down and it has some clues about power. As with old series through hole resistors the wattage MAY be relative to size. So try and measure the resistor and that will narrow your search down dramatically.

Is it completely burned or were you testing it for 105 ohms - if so try testing it for 1mohm

[withalligators]

Re: HP 2509m won't turn on, no power to ON/OFF LED

Somehow I missed this last post. Thanks for the very helpful info, Selldoor. After measurement, I've added this this to my cart. I don't think I'm going to need to replace the IC, so that's on the backburner, unless I can't get it going. I'm having a hell of a time finding a replacement for the 2 mosfets though.

Selldoor, in a previous thread, you had suggested using FDD8451 and AOD413 as a pair. Do you still think it these are a good choice even though P5506BDG and P9006EDG are 60V and TO-252 and FDD8451 and AOD413 are 40V and TO-263?

I'm very much a beginner at component level stuff, so I have no idea one way or the other, it just seems like too much doesn't match up.

It might be in the interests of time to just go ahead and order exact replacements off ebay, even though they are kinda marked up. I think it was a bad batch of bulbs (that I'll have to fix later) that caused these components to fail rather than the components themselves being particularly poor. That said, most of the matching stuff was bound from china, so who knows what it actually is.

Thanks so much for your help!

Alex

[selldoor]

Re: HP 2509m won't turn on, no power to ON/OFF LED

Selldoor, in a previous thread, you had suggested using FDD8451 and AOD413 as a pair. Do you still think it these are a good choice even though P5506BDG and P9006EDG are 60V and TO-252 and FDD8451 and AOD413 are 40V and TO-263?



Alex

Its a long time ago but I think I must have not had brain in gear - sorry if it got your hopes up at least you spotted it before trying to order.
Surprisingly no one picked up on it at the time!!

Yes most of these odd fets have to be ebayed from China I dont know if they are new or whether they just buy in all the scrap from OZ and recycle it.

[withalligators]

Re: HP 2509m won't turn on, no power to ON/OFF LED

Ok, update for anyone's future reference that intends to follow the same path. I replaced the diode, the resistor, and the P5506BDG with an exact off ebay (links to what I bought on digikey). It now sees power and the button lights up. The screen powers on and flickers constantly. I am now going to order the CCFLs and report back when that's done.

[withalligators]

Re: HP 2509m won't turn on, no power to ON/OFF LED

I FINALLY got around to fixing this. I replaced all four CCFLs but I probably only needed to do the bottom 2. All four doesn't hurt though, as these from the factory are notoriously prone to shorting, as the guys at CCFL warehouse told me. The correct size is 2.4 x 570mm, and I bought a 4 pack from them for 35 including shipping. I really screwed up on the first set, and broke both. I learned a lot though, and got a good methodology going, and the second attempt on the first set went smoothly. I then had to order another pair to finish the bottom set, which went well, and now I have fully working monitor with a backlight that will hopefully last a long time.

Some tips to anyone attempting this repair:
(sorry for not taking pictures, I should have documented the job)

Go ahead and cut the small wires a few inches between the plug and the bulb. You WILL need some slack to work with these very fragile bulbs. You can always solder them back together after. I cut out a few centimeters from the ends where they were heat damaged, and soldered in a section of thin wire off of a case fan into the initial cut.

Don't worry too much about saving the silicon caps. I was able to save the more pliable ones by making incisions in the outer part (conserving the part inside that divides the two bulbs) and pulling out the bulb and wire connections laterally. When soldering on the new bulbs, be mindful of the orientation of the wire leads. They will only fit one way, and each end is different. After you have them inserted back into the silicon ends, use some silicon sealant to repair any damage to the end caps you may have done. Two of my end caps were so brittle from heat, that I destroyed them entirely. I simply encased them in aquarium silicon and then trimmed them to fit after they had dried.

Overall, I would do a bulb change again, but the first attempt really sucked, and was very frustrating.

[bobotech]

Re: HP 2509m won't turn on, no power to ON/OFF LED

Thanks for this thread. I just got a 2509m monitor at my recycler with the same symptoms. No power, no led, no nothing when plugged in. Looked like it was in beautiful condition though so I snagged it for 5 dollars.

I was disappointed when there were no blown caps on it though. LOL But at least this thread is like roadmap how to fix this monitor.

[withalligators]

Re: HP 2509m won't turn on, no power to ON/OFF LED

That's the whole point of these updates. I wanted to gather everything up into one place. I found it very irritating having to read other threads where you only get part of the info or everything right up to where the poster presumably solves it but doesn't bother posting their success. Careful with those bulbs. Pull out and check both sets. It's entirely likely you'll only have to replace one pair, and not both.

[horde5150]

Re: HP 2509m won't turn on, no power to ON/OFF LED

Interesting. I'll be following this thread. My 2509m (Refurb, rebranded Famous Maker no less), JUST died last night while playing a game. Prior to that, picture was perfect. No flicker, no dimness, then poof. It seems there is no definite reason for this.

Are the bulbs to blame for this? Seems everyone that is replacing mosfets mentions the dimness afterward. I am possibly tempted to just chunk this thing if it is more trouble than it's worth to repair it (Unlike almost every other LCD monitor I've repaired). But I do like a challenge.

Has anyone decided on absolute replacements for the mosfets? It almost sounds like the flickering and dimness are a result of incorrect replacements. Is there that chance?

[withalligators]

Re: HP 2509m won't turn on, no power to ON/OFF LED

I used what is an exact replacements. At least, that's what I bought, but it may have been relabeled. Since I didn't own this thing when it went out, I couldn't tell you what the shutdown failure is like.

Also, I'm not sure you read the thread well enough. The dimness is because the bulbs die and take the daughter board with them. Just to get the thing running, you have to fix the daughter board. But then, your bulbs are also dead, so you get dimness on one side, or flickering. When you fix the bulbs, you are good to go. My monitor is fantastic now. The problem (I've read) is the bulbs put in by LG, (the panel manufacturer), apparently there was a bad batch, or bad connections, or something like that. So when you fix both, you ought to have a fairly long lived monitor.

[withalligators]

Re: HP 2509m won't turn on, no power to ON/OFF LED

For what it's worth, I have an extra pair of bulbs left over from my second attempt. They are new, right from the factory, without a finger print on them. If anyone is interested, I'll sell them cheaper than CCFLwarehouse.

PM me.

[horde5150]

Re: HP 2509m won't turn on, no power to ON/OFF LED

That's excellent news! And thank you for the links. I'll be picking up these pieces, and if my screen is dim (which I assume it definitely will be), I'll get back with you if you have not found a buyer for them yet.

Thanks again, and sorry I was confused with the order of destruction.

[horde5150]

Re: HP 2509m won't turn on, no power to ON/OFF LED

Hour 1. So far so good.

I have replaced the Diode, Resistor, and the Transistor on the daughter board. I got VERY worried about the transistor replacement, because although it was removed easily with almost no energy at all, the pad under the Gate pin (Pin 1) lifted. Even before the entire process the board was a dark brown on that side, more than likely heat generated from the P5506BDG.

The Diode and Resistor came from DigiKey, and the new transistor from Ebay (see withalligators' exact item replacements).

Not sure why, but I did not see any dimming or flickering CCFL afterward.

History of this "Rebrand": I got it through Woot during one of their wootoffs. When I received it, there was some rattling around inside. When I opened it, there were two screws that should have been holding the power board in, free-roaming around. I would think if it was a short it would have happened immediately, because the monitor was perfectly still crapped out. But it's working now. Time will tell!

Thank you for your valuable input, withalligators!

[bestpaul1985]

Re: HP 2509m won't turn on, no power to ON/OFF LED

I fixed my monitor by following this thread.
Thank you so much for your help!

Paul

[withalligators]

Re: HP 2509m won't turn on, no power to ON/OFF LED

Thanks for the feedback, and glad it helped you!

[Freezer]

Re: HP 2509m won't turn on, no power to ON/OFF LED

I recently picked up a broken 2509m off craigslist which does not power on at all. I'm still diagnosing the problem, but I suspect the problem is the 2 mosfets and the diode everyone speaks of in this and other threads about this monitor. As others have noted, these 2 mosfets are no longer available, so most people resort to buying high priced "originals" off ebay from China. But who's to say the quality of these. I'm hoping to find suitable replacements on digikey. I know how to select replacement caps, but mosfets are components I haven't dealt with much. Can anyone look over the following and see if I'm on the right track:

When you look at the datasheets for mosfets, it seems the key characteristics are:
Drain source voltage | V(br)dss
Drain source on resistance | Rds(on)
Continuous drain current | Id
Power dissipation | Pd
Gate threshold voltage | Vgs(th)

To find a suitable replacement, here are my thoughts.

1. V(br)dss should be the same as the original, higher if necessary.
2. Rds(on) should be as low as possible. Sounds like the lower this value the less heat is generated. I don't think you need to try and match the original Rds(on) value, just go low.
3. Id should be at least the same value as the original. Going higher should be fine, this is just the maximum amps it can pass, doesn't mean it will pass that much though.
4. Pd should be as high or higher. The replacement mosfet needs to be able to dissipate as much power as the original, but more should be just more headroom.
5. Vgs(th) should be as close as possible to the original values.


So assuming the above are correct assumptions, the following are what I come up with as suitable replacements. Oh, I kept the package type the same (TO-252) cause I don't want to deal with jumper wires where pins and pads don't line up.


Original: P5506BDG N-channel:
V(br)dss = 60V
Rds(on) = 55mohm
Id = 22A
Pd = 50W
Vgs(th) = min=1V, max=2.5V

Best replacement: STD20NF06LT4 N-channel:
V(br)dss = 60V
Rds(on) = 40mohm
Id = 24A
Pd = 60W
Vgs(th) = min=1V, max=2.5V

For the P5506BDG N-channel this seems like a good fit. Lower resistance, more power and amps, and everything else the same.


Original: P9006EDG P-channel:
V(br)dss = -60V
Rds(on) = 90mohm
Id = -8A
Pd = 28W
Vgs(th) = min=-1V, max=-3V

Best replacement: SPD09P06PL G P-channel:
V(br)dss = -60V
Rds(on) = 250mohm
Id = -9.7A
Pd = 42W
Vgs(th) = min=-1V, max=-2V

For the P9006EDG P-channel this is less ideal of a fit. The resistance is higher so more heat. But the Vgs(th) has me concerned. Does lowering the max voltage from -3 to -2 cause a problem?

The other option is: DMP10H400SK3-13 P-channel:
V(br)dss = -100V
Rds(on) = 240mohm
Id = -9A
Pd = 42W
Vgs(th) = min=-1V, max=-2V

Slightly better resistance and a perfect match on Vgs(th), the voltage increased up to 100V which I don't think should be a problem.

Thanks for any advise.

[withalligators]

Re: HP 2509m won't turn on, no power to ON/OFF LED

This is a great addition to this thread. I hope someone more knowledgeable chimes in to help and that you post back with your final results. It would be great to not have to order questionable parts for everyone that does this fix in the future.