The monitor flashes amber and there is a clicking sound and there is no picture

The HOT was found shorted so I replaced the HOT 2SC5445 with 2SC3997 coz i couldn't find the original one ...

Also the D6508 Was found shorted but i couldn't find a replacement so far ... the Original one is 5TUZ52C ... i'll appreciate it if you can tell me about a suitable cross reference ...

Also there is no voltage at the HOT ...
There is no voltage on the B+ as measured across the following components
ACROSS C2362 Which should be "+ 8.0V +/- 0.5 VDC"
ACROSS C2143 Which should be "+ 5.0V +/- 0.5 VDC"
ACROSS C2361 Which should be "+ 12.0V +/- 0.5 VDC"
ACROSS C2134 Which should be "+ 15.0V +/- 1.0 VDC"
ACROSS C2137 Which should be "- 15.0V +/- 1.0 VDC"
ACROSS D6148 Which should be "+ 6.3V +/- 0.5 VDC"
ACROSS C2131 Which should be "+ 210.0V +/- 1.5 VDC"
ACROSS C2133 Which should be "+ 82.7V +/- 2.0 VDC"

The 7121 IC has Vin of some 900 Volts , i dunno where they come from ,and the Over-Current and feedback pin has a 13-14 volts

the unit still flashing and clicking !

Any Ideas ?

Hi are you checking Vin on pins 4 & 5 of IC 7121.

Rich

Yes Richard

On Pin 4 As Vin and Pin 5 as Gnd of the IC 7121 , it starts at some low voltage and increases and seem to stabilize at 900 volts

What do you think ?

Sorry Richard

I can't believe i was fooled by the pin arrangement :s
anyway , pin 4 is 13 to 14 volts and pin 1 is 0 volts

Sorry again Richard ...

This problem seems to be a common one on this perticular chassis ...

The problem lies in

7541 Power FET 2SJ448 (Or 2SJ512) [Shorted]
7502 HOT 2SC5445 [Shorted]
6508 Damper Diode 5TUZ52C [Shorted]

Can anyone tell me what can cause such damage ??? I do not want to replace all of these and find them burned again ....

Note.
I measured the B+ 210 line and it turned to be 218V ...

Thanx

The problem Was

7541 Power FET 2SJ448 (Or 2SJ512)
7502 HOT 2SC5445
6508 Damper Diode 5TUZ52C

I dunno what causes this problem really maybe a bad filter capacitor or the high voltage capacitors around the HOT so i replaced the following caps too ...

2103 Electrolytic Capacitor [Main Filter Capacitor] 330uf 400V
2506 Ceramic Capacitor [High Voltage Capacitor Around HOT] 220p 2KV
2507 Ceramic Capacitor [High Voltage Capacitor Around HOT] 220p 2KV
2508 PPNS Capacitor [High Voltage Capacitor Around HOT] 4N7 2KV
2542 MEF Capacitor 100n 250V

After replacing these components , the monitor works fine ... Though the HOT runs hot, a bit more than i can stick my finger on it for a while...

Thank you all for help , and i hope this post can help someone with a similar problem ...

This is one is very suspect:
2508 PPNS Capacitor [High Voltage Capacitor Around HOT] 4N7 2KV

One must always replace snubber capacitor , which are 1600V or 2000V,
whenever the HOT is shorted

Regards

Moses
www.monitor-repair.com

Ok now i am back to the first problem that i believe, it originally made the HOT blow ...

the monitor shrinks the horizontal size from the right side only ....

and i believe that if i left it open for enough time maybe an hour or 2, it will blow the HOT ...


what happens is ....
When i start the monitor from cold ... it starts with a normal size and everything is alright .... and as it warms up the size begins to shrink from the right side only ...
and the size shrinks gradually that you do not feel it is happening ... but after a 30 minutes or so you find that the horizontal size has shrunken with an inch or so from the right side only ...

Where the fault could be ???????????????

Right hand side cramping is due to poor drive of the HOT.


Check for poor solder joints on all the components around the drive TX ref 5501.

Rich

Richard b,it not dry joint and can check by hitting cabinet to picture.it cause by some filtering capacitor nearby horizontal circuit.
you remove capacitor and check the capacitance?

Hi All,

Before i got the same problem but I made to restore after a thourough checked on the B+ path and horizontal section then i am using it for about a year "i think so" since i'd made my repair last year then last week the monitor got dead again until i replaced the busted HOT 7502 with (2s5144),the 7541(2SJ512) and 2502 (1uf/160v np cap) with two 2.2uf electrolytic cap in series (goes like this + - - + )these became a 1.1uf non-polar cap, isnt it? pls correct me if im wrong. The only part that i didnt replace was the so called snabber cap (2508 PPNS Capacitor [High Voltage Capacitor Around HOT] 4N7 2KV).

Now I am currently using it but until i noticed some changes that horizontal size changes slowly on both sides to shrunk at normal operation then some time a TIC sound occured ramdomly and got rapid changes on the picture during the TIC sound occurance that it gets dimmer picture, horizontal and vertical change rapidly (picture expand) then slowly back to normal as it goes slowly changes the horizontal size to shrunk.

I really needed someones advice...What causes these problem?
I am posting this before it could totally damaged my Compaq V1100.

Please, help!

Hi!

What should be the value that i must follow for this part# 3441? cuz' i found out that the actual value that was on the mainboard measured 62k or colored as it is 62k and on the schematic or even on the part list description it is only 33k...should i replace this 68k into 33k? could it be the origin of some problem on this chassis? To those who owned or service this monitor, what was the value of the part#3441 of your compaq V1100? is it 62k or 33k?

Pls help!

Hi there are 2 versions of this unit.

1 is the Philips 201B CM25 plus which has 3441 as 33k
2 is the Philips 201P CM25 V2 GS3 which has 3441 as a 56k.

Rich

Hi rich!

Thank you for the respond it is the Philips 201B CM25 plus which has 3441 as 33k,(CM25+ with FCC ID: A3KM094). Do you think that part should be 33K? I wonder if they made some revision on this models! Now i would like to ask (especially the one who originated the posted problem) for those who service this model on how they found on this part # or "What was the actual value of that part at the mainboard?" was that part something suspicious on this model that causes many trouble on the horizontal section? Please help me!

Thank you again Richard.

gino69

Richard B,

Hi there! I tried replacing 3441 from 62k to 33k and the horizontal size gets smaller that you could not full the screen area even on the optimum setting of the horizontal size, but the HOT was not as hot as the 62k value (cooler than 62k). Then id replaced it back into the original value and the i could now set the H-size into full screen...and back into basic problem that the HOT was too hot(very hot), as it goes hotter the horizontal size slowly gets shrunk. specially at the right side of the screen.

is there any remedy for this?

gino69