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**FIXITNOW** · 02-17-2009, 01:54 AM

Re: HP F1523 - 2 secs display then darkness

replace the 4 large caps with good quality ones

**PCBONEZ** · 02-17-2009, 02:37 AM

Re: HP F1523 - 2 secs display then darkness

I think I see Elite's in there and those need to go.
They are just junk and a common problem in LCD screens.

If you can give me the series' you see then I will try to link you to the specs.

.

**CariadBach** · 02-17-2009, 03:06 AM

Re: HP F1523 - 2 secs display then darkness

Hi FixItNow & PCBonez

Many thanks to both of you for the prompt replies.

I can source replacements for the large caps from my local Maplins.

PCBonez
Apologies for my ignorance - I'm rather new to this level of fixing things. What do you mean by `the series`?

**CariadBach** · 02-17-2009, 05:20 AM

Re: HP F1523 - 2 secs display then darkness

Hi again

I've been reading up to try and answer my own question.

Yes, the 4 large caps are Elite. The series is PF(M) and the sizes are:

2 x 1000uF 16v 105C
2 x 1000uF 25v 105C

**Bobdee** · 02-17-2009, 07:16 AM

Re: HP F1523 - 2 secs display then darkness

Hello CariadBach
Welcome, if you really like your Monitor,go with PCBonez specs, as craplins only sell general purpose Jamicons, they will do it, but wont last and give you problems later on, you need low esr, PCBonez will suggests the replacement specs, and possibly a link as where to get them

**CariadBach** · 02-17-2009, 07:27 AM

Re: HP F1523 - 2 secs display then darkness

Hi Bobdee

Diolch yn fawr ;-)

My impatience got the better of me this lunchtime & I replaced the 4 listed caps with Jamicons from Maplins.

However, no joy - the same problem. 2 seconds of brilliance then the backlights are no more.

So, I now have 2 questions:

PCBonez - thanks for your offer of identifying suitable replacement specs. Do you have enough information to work with?

Everyone - any ideas where the next are of diagnosis is?

**Bobdee** · 02-17-2009, 08:44 AM

Re: HP F1523 - 2 secs display then darkness

hello again
can you post better photo of your board, both sides, clarity is poor, it will help others to help you, In the meantime check all solder joints with 8 or10 x magnifying glass for bad solder joints plus ring cracks in joints,pay particular attention to transistors and mosfets as well as anything on heatsinks, plus transformers,you may get lucky,best of luck
bob

**PCBONEZ** · 02-17-2009, 10:39 AM

Re: HP F1523 - 2 secs display then darkness

I think you got it. - Series is like the model name.
All caps in any series from a given brand will be the same grade.
Same grade means same Ripple and ESR [relative to other brands and Series'].
Grade is how you cross reference equivalents.

You should replace -ALL- the Elite caps.
Are there any other series of Elite present?
Are there any other brands present? Elite isn't the only possible bad brand.

PF are GP [General Purpose] and not Low ESR so only Ripple is shown in data sheet.

On the two you've given ripple is:
1000uF 16v -> 680
1000uF 25v -> 830

I would use Panasonic FC series to replace Elite PF.
FC are low ESR and much better grade but still inexpensive and very reliable.

Other series' of Elite may of higher grade than FC which is why the series question must be asked before recommendations are made.

** When replacing caps you need to verify the diameter of replacements will fit. Some size cap [by uF and volts] in one brand may be 10mm diameter but in another brand or series it's 13mm [or too tall] and won't fit.
- Check original diameter and height requirements by direct measurement of old caps. [Not by looking in data table.] Sometimes custom physical sizes are used those aren't in the data tables.
.

Attached Files

PF.pdf (78.7 KB, 53 views)

**anno** · 02-17-2009, 04:38 PM

Re: HP F1523 - 2 secs display then darkness

there is a problem in the inverter.check fuse on inverter , check mosfets / transistors for short circuit. resolder pins of the transformers.

**CariadBach** · 02-18-2009, 11:42 AM

Re: HP F1523 - 2 secs display then darkness

Hi everyone

Thanks for the information to date. It's super and I'm having a blast!

PCBONEZ, thanks especially for the Elite spec - its all making sense (slowly...)

So far I have replaced 5 caps (albeit with Jamicons from Maplin).

The caps replaced are the 4 Elite ones detailed previously and a Su'scon 220uF 50V one simply because Maplin had one in stock.

For the record, the remaining electrolytic caps are:

a large 100uF 400v 105C Rubycon LS (which I assume smooths the power?)
a pair of Su'scon 10uF 50V
a single Capxon 10uF 25V located close to the pair of 1000uF 16V ones
a pair of Capxon 680uF 25V
a Capxon 1uF 50V
a Capxon 2.2uF 50V
a pair of Su'scon 22uF 50V
a pair of Su'scon 10uF 50V

None `appear` in trouble but what do I know!?

Will spend the next couple of days resoldering and will update with better pics as BobDee suggests.

ANNO
How would I recognise the inverter fuse?

**anno** · 02-18-2009, 02:37 PM

Re: HP F1523 - 2 secs display then darkness

there are marking on the board . like PF = polyfuse F=fuse
i can`t see it on your photo`s. they are not good enough

**anno** · 02-19-2009, 10:41 AM

Re: HP F1523 - 2 secs display then darkness

sorry i made mistake. i thought it was a benq power supply.

**EGuevarae** · 02-19-2009, 11:59 AM

Re: HP F1523 - 2 secs display then darkness

Originally posted by anno

sorry i made mistake. i thought it was a benq power supply.

Yet, the markings on the silkscreen should be the same. Here are pics of three types of fuses. Hope this helps.

SMD Fuse

Attached Files

**CariadBach** · 02-19-2009, 03:42 PM

Re: HP F1523 - 2 secs display then darkness

Hi

thanks for the updates Anno, EgueVarae

Maybe I've been a bit of a duffer here!

There is a rather obvious fuse with rating T3.15A/250V located near the power area of the board (top right of the 1st picture posted).

I assumed that it was simply a fuse similar to the mains supply fuse i.e. to restrict the current draw. The fact that power is getting through made me ignore it.

Is this the `inverter` fuse? I'll find out tomorrow regardless because I can swap out easily.

**EGuevarae** · 02-19-2009, 04:17 PM

Re: HP F1523 - 2 secs display then darkness

Originally posted by CariadBach

Is this the `inverter` fuse? I'll find out tomorrow regardless because I can swap out easily.

No, or at least not the one I (and I think anno too) was referring. That is the Main AC fuse, at the AC input. Look at the attached pic. The ones in green are the AC input fuses (different type, same function), and the one in blue is the inverter fuse.

Attached Files

**Krankshaft** · 02-19-2009, 05:10 PM

Re: HP F1523 - 2 secs display then darkness

What is the IC number on two of those twin 4 pin DIPs to the right of the inverter transformer?

I'm willing say that they are DIP transistors and they drive the inverter transformer and one of them may be shorted.

I'll get you a datasheet if you can give me the IC number so you can test them.

**Bobdee** · 02-19-2009, 06:44 PM

Re: HP F1523 - 2 secs display then darkness

hello again that fuse that you are look for, may also be black , resembling a resistor but more like a small diode, but all black, but it will have F something marked on board
bob

**CariadBach** · 02-20-2009, 09:45 AM

Re: HP F1523 - 2 secs display then darkness

Hi everyone

I'm at a loss in search of the inverter fuse.

As BobDee suggested earlier, some improved pictures should help. Please restrict your mirth at my soldering prowess to 5 minutes only :-)

Hi Krankshaft

I'm attempting to answer your question without displaying my true ignorance here. Are you referring to I102 & I103? If so, the print is very faint but I can read P600 BD4C15.