Dell 2007fpb no power

[jetadm123]

Re: Dell 2007fpb no power

Just received the data sheet on the chip I need, discontinued of course. Got it straight from Fuji Electronics, any help finding a replacement?
thanks

Hello! I suggest you try NTE Electronics (nteinc.com). They are a large manufacturer of aftermarket substitute electronic parts. While I did not find your transistor in their cross reference guide, I suggest you contact their technical support with a copy of your spec sheet and maybe they can suggest a NTE replacement. Please post your results if you get a reply.

[jetadm123]

Re: Dell 2007fpb no power

Just received the data sheet on the chip I need, discontinued of course. Got it straight from Fuji Electronics, any help finding a replacement?
thanks

Oh yeah, I forgot to mention that when you contacted Fuji did you ask them if they could suggest a substitute from their current line of transistors?

[ihatedeskjets]

Re: Dell 2007fpb no power

Don't worry. In worst case scenario you can always wire an external power supply. Something along the lines of 12v, 4-6A should be good enough.

Hi everyone, I've just found this old thread and wonder if someone could point me towards the solution above, I would love to revive my old 2007 FPb but my eyes aren't good enough these days to fault find the entire psu.

As I remember the monitor began flickering one day, then burning, and then dead, the fuse is ok as is the bridge. The 8 pin I.c Seems dead however.

I would really like to just hook it up to an external supply, Do I just connect to the + & - behind C711 ?

Thanks in advance

[jetadm123]

Re: Dell 2007fpb no power

Hi everyone, I've just found this old thread and wonder if someone could point me towards the solution above, I would love to revive my old 2007 FPb but my eyes aren't good enough these days to fault find the entire psu.

As I remember the monitor began flickering one day, then burning, and then dead, the fuse is ok as is the bridge. The 8 pin I.c Seems dead however.

I would really like to just hook it up to an external supply, Do I just connect to the + & - behind C711 ?

Thanks in advance

You'll need to post some clear focused photos of the entire power supply top and bottom of YOUR supply. I recently wasted time helping someone, by pointing out problems i saw on their photo only to find out that they were using photos from someone else's supply. No disrespect, but pointing to a specific component like C711 without photos is like me asking you to take voltage measurements with your eyes closed.

[ihatedeskjets]

Re: Dell 2007fpb no power

sorry, forgot to mention it's the same psu (identical part number) as in the earlier post with all the pictures and info. The capacitor I'm thinking of is at the top of pic 1,and the tracks run down the right hand side to TP712 and TP711.

Thanks

[ihatedeskjets]

Re: Dell 2007fpb no power

Lost the ability to edit but here's the pic

[jetadm123]

Re: Dell 2007fpb no power

My apologies, I should have asked you to post your photos using the "manage attachments" button. Posting them inline will slow the loading process and require some members to have to scroll through their screens in order to view your photo. Also, regardless of what photo someone else posted, we need to see your power board because trained eyes may see something on your board that you may have missed. Please repost the top and bottom photos of your power board.

[ihatedeskjets]

Re: Dell 2007fpb no power

My Daughter is on holiday with my decent camera, I won't waste anyones time with poor quality webcam pics. Besides I really don't want to repair this board, as I said I would rather just attach an external unit.

I'll put 12v on the test points and see if it powers the rest of the unit. I suspect looking at the circuit i'll lose the ability to turn it off by the soft touch panel button, but that's not important to me, I can pull the plug.

Thanks for your time.

[momaka]

Re: Dell 2007fpb no power

I would really like to just hook it up to an external supply, Do I just connect to the + & - behind C711 ?

You can connect the external power supply anywhere you like, as long as the polarity of your external PSU is matched to that of the LCD power supply. Just DO NOT connect the (+) of the external PSU to any of the pins on the transformer of the LCD's power supply. Removing one of the caps and connecting the external PSU there should be fine.

I'll put 12v on the test points and see if it powers the rest of the unit. I suspect looking at the circuit i'll lose the ability to turn it off by the soft touch panel button, but that's not important to me, I can pull the plug.

Fortunately, the power supply in this monitor has only 1 voltage rail, therefore that voltage rail is always on. This means that the ON/OFF switch will actually work properly as it did before.

Now, what I'm more concerned about is the external power supply you'll be using.
- First, it needs to be able to handle at least 4 Amps, just to be on the safe side.
- 12v might actually be a bit too low. If you look again at the first post on page 1, you'll notice that duceolsen measured 20v on the original power supply. Check the electrolytic caps first, though - if they are 16v caps, then don't use anything more than 16v. If the caps are rated for 25v or more, use something closer to 20v (a 19.5v notebook power adapter rated for at least 3.5 Amps sounds reasonable)

Also, make sure that the power supply in your monitor is *exactly* the same as the one pictured in this thread. If it's slightly different, don't do anything until you post some pics.

[ihatedeskjets]

Re: Dell 2007fpb no power

Hi all,
I've ordered a HP PPP014S 18.5V / 4.9AMP POWER SUPPLY and isolated the mains input end for safety by lifting the fuse. I hope the 20v mentioned earlier was measured on the secondary side. This monitor does have P.I.P for multiple inputs and 4 usb's so I think a little more than 12 will be ok, thanks for the advice and I'll post the results when the psu arrives.

[ihatedeskjets]

Re: Dell 2007fpb no power

I'm pleased to report that my 2007fpb now runs from an external supply, the HP laptop supply works perfectly at 18.9 V measured across the test points TP 711 (+) and TP 712(-) .

It's also a LOT COOLER so in improvement I think.

Thanks for the help all.

Ken

[Compiro]

Re: Dell 2007fpb no power

Hello Guys,
I am trying to repair the power board of my monitor (it is also a 2007fpb) and it seems a capacitor is destroyed.
I want to replace it but the values are destroyed aswell. Can anyone tell me the value of capacitor C601? It is the only rectangular capacitor in the board. Or if someone has the scheme of this board it would also help.
Best regards,
Josué

[tommy_b]

Re: Dell 2007fpb no power

For posterity, the value of C601 is 0.22uF 275Vac. Looks like its from a Chinese manufacturer called "AV Capacitors" (AVX knockoff? :-).
Here are some numbers I found on it:
R.46 MKP X2 SH
0.22uF 275Vac
40/110/56 B B TN

I found this link to what is likely the same cap, but the p/n is slightly different (i.e.,
R.46 MKP X2 SH HP
0.22uF 275Vac
40/110/56 B S B1:
http://www.aliexpress.com/item/Av-r4...690480736.html

[Michele31415]

Re: Dell 2007fpb no power

Hmm - my apologies for tacking onto this thread but I don't seem to be able to start a new one despite having registered and posted an introductory post already.

Anyway, I have a Dell 2007FPb with no power. Examination of the power board quickly showed that C605, the big 180 uF 450 V electrolytic is dead. The + lead was corroded clean through. Also, the main 4A fuse, F601 is open. Naturally I did not have either of these parts in stock. So while I'm waiting for them to arrive, any suggestions on what's possibly going on here? Is it likely that the cap just failed and then took out the fuse, or did something else downstream kill the cap? Thanks!

(The other electrolytics on the board looked good and tested OK on the ESR meter. There are no obvious burn marks anywhere on the board, front or back.)

I sure wish I could find a service manual for this thing.

[budm]

Re: Dell 2007fpb no power

https://www.badcaps.net/forum/showth...+2007+teardown

[Michele31415]

Re: Dell 2007fpb no power

https://www.badcaps.net/forum/showth...+2007+teardown

Yes, I did see that thread but it doesn't address the main power supply board. Anyway, while waiting for my new parts I checked both the chopper transistor and the big Schottky diode for shorts, but they seem OK at least by a quick resistance check.

I guess I'll just replace the fuse and the cap and then slowly run up the power supply on the variac while monitoring the current draw. If there's something seriously wrong early on the input side, it should manifest even if the board doesn't run.

While we're at it, here's what that fried capacitor looked like. The positive lead is eaten clear through. That's one Bad Capacitor.

[Michele31415]

Re: Dell 2007fpb no power

Well I kinda feel like I'm talking to myself here, but here goes anyway. I checked the bridge rectifier on the power supply board but didn't find any shorts there. However, I noticed a third heatsinked part, a three terminal jobber called BD601. The right hand terminal is connected directly to the burned capacitor. And it is a dead short from that terminal to the center terminal of BD601. That doesn't seem right. I'm going to take a wild guess that I need a new one. And of course, Mystery Part BD601 has no visible markings on it.

So can anyone tell me what a BD601 is? Pretty please?

[budm]

Re: Dell 2007fpb no power

OK, I am a little confused, the pictures show the 4-pin device which is the Bridge rectifier BD601, but you said you did not find any shorts ('I checked the bridge rectifier on the power supply board but didn't find any shorts there')
The two inner pin are for incoming AC, the two outer are the + and - output, the left pin in your picture is the negative leg which goes to the negative leg of the main filter cap, the one on the right is the positive which is connected to the positive leg of the main filter cap.
Right now you reading shows that you have shorted Bridge rectifier, you need to remove it off the board. There is P/N printed on that bridge.
Did you also check the power MOSFET?
Also the AC inlet CN601 Neutral pad looks like jumper is removed? I see empty hole on the pad.

[Michele31415]

Re: Dell 2007fpb no power

Oh duh! No, you're not confused, I'm confused. I checked a square four-pin SMD called IC602 near the top of the board. I thought that was the bridge rectifier. Then I noticed BD601 but thought it only had three pins - it was hard to see the fourth pin hiding down the end of that thing. You are quite correct - BD601 is clearly the bridge rectifier and it's shorted out. Unfortunately, whatever markings it had were vaporized and it's just blank now. It's really hard doing all this without a schematic.

The hole at CN601 is where I pulled the blown 4A ceramic fuse - good eyes. I'm still waiting for my new fuse and cap. I guess now I need a rectifier too. At least the problem is looking more clear now. The rectifrier went south and applied AC to the electrolytic. That did its best to protect the fuse but it was all in vain and they both finally gave up the ghost.

[Michele31415]

Re: Dell 2007fpb no power

I pulled the bridge rectifier. The writing was on the back side. For future reference, it is a Vishay Seminconductors GSIB4A60, a 4 A 600 V rectifrier. This part is apparently obsolete and superceded by a GBU406. Widely available and cheap. I'm somewhat surprised they used such a high-rated part, and heat-sinked at that.