Hp l1955 - pd974/ 48.l1a02.a31 help needed urgently!

[audio789]

Hi, I have read all of the threads here already regarding HP 1955 but I am still little unclear. First of all the details:

Monitor: HP L1955
Board: BenQ 48.L1A02.A31 / PD974
Problem: The monitor (when on standby) would hum/buz around the inverter area but worked fine untill one day had plenty of smoke and then a bang and dead.. i havn't turned it on since.
Current Situation: 7th March 2011 - I have opened it up to find some serious burnouts on:
Q808, Q809, Q805, C824

However the 5A fuse is fine on PF701

From reading your posts i realise I should be replacing: Q808, Q809, Q805, Q812, Q815, Q816 and C824

I have done my best to research what to purchase and have come up with this so far:

C5707 x 4 - Q808, Q809, Q815, Q816
FQU11P06 x 2 - Q812, Q805
R75MKPSN x 1 - C824

I will be posting pics tomorrow as the picture below is one i found...

Is there any thing else i can/ need to do?

Do I have the right components listed that i need? Are there any others I need?

Lastly, I understand everyones replacing the burnt-out parts but does this really combat the root of the problem?

Thanks in advance for reading and any help is truly appreciated indeed.

[Lumberjack777]

Re: Hp l1955 - pd974/ 48.l1a02.a31 help needed urgently!

I've seen a lot of repair kits for your monitor on eBay. They are about 5 or 6 bucks including shipping.

I have fixed that model of monitor before. Twice actually. Last one had a blown fuse and a shorted C5707. But I went ahead and replaced the fuse and all the C5707's, and the FQU11P06's, just so I won't have to open it up again. (for awhile)

Nobody knows for sure without pictures and some tests if that's all you'll need. But those are the most common components to fail on that model, in like 80% of the ones I've seen.

As for the cause. From what I've read, it has an inferior electronic design, that puts too much stress on the C5707's.

[sabre504]

Re: Hp l1955 - pd974/ 48.l1a02.a31 help needed urgently!

Resoldering the transformer legs and check for other dry joints on the back of the psu board

[audio789]

Re: Hp l1955 - pd974/ 48.l1a02.a31 help needed urgently!

UPDATE:

I've removed the board and checked the bottom of it to find some serious burns to the bottom of Q808 Q809 so bad the copper has started to lift from the board and is a bit weak.

What is the soloution to this problem? Ablob of solder? or some wire? if so what type wire?

Thanks guys, all advice is priceless.

[jetadm123]

Re: Hp l1955 - pd974/ 48.l1a02.a31 help needed urgently!

UPDATE:

I've removed the board and checked the bottom of it to find some serious burns to the bottom of Q808 Q809 so bad the copper has started to lift from the board and is a bit weak.

What is the soloution to this problem? Ablob of solder? or some wire? if so what type wire?

Thanks guys, all advice is priceless.

You can try one of the following:

1) solder a 18-20 gauge copper wire to the lead of the c5707 and connect the other end of the wire to the solder pad of another device that is connected to the copper trace that has lifted.

2) if the leads of the c5707 are long enough, bend them over and solder them directly to the portion of the copper trace that is still good. Make sure you scrape off the coating off the trace with some fine sandpaper or a sharp hobby knife to expose the copper.

[JesusSSSSSSS]

Re: Hp l1955 - pd974/ 48.l1a02.a31 help needed urgently!

Hello, I need help.
I want to know the references number of the component IC701.

Thank You.

[selldoor]

Re: Hp l1955 - pd974/ 48.l1a02.a31 help needed urgently!

@jesusssssss There may be more than one type of board used in the L1955 What
is you board part number. Can you see any of the part number on the IC107 you have. If not destroyed try cleaning with isopropyl alcohol.

Welcome to the forum-
We can help a lot more if you please post good clear pictures (max resolution 2000x2000 and 2MB) using the manage attachments button, which is found by clicking "go advanced" under quick reply.

Please do not post inline and offsite as they slow down the loading of pages.

Examples of what is needed
https://www.badcaps.net/forum/attach...1&d=1290283049

https://www.badcaps.net/forum/attach...7&d=1280167246

[JesusSSSSSSS]

Re: Hp l1955 - pd974/ 48.l1a02.a31 help needed urgently!

Thanks, finally wiping with acetone I see the number.

[budm]

Re: Hp l1955 - pd974/ 48.l1a02.a31 help needed urgently!

This one is made by BenQ, make sure to check the tunning caps by the inverter transformers.