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sir, when power on the monitor screen show blue with retrace line but next time power on the display is white with retrace line (this is IBM CRT 14”monitor model no – 6540 – 02e) and horizontal out put transistor(C5802) is very hot. how i solve this out put hot problem  and retrace line ?

Hi Nihar,

retrace line are due to excessive  g2 voltage or G1 voltage is too low. Sometimes a weak screen also can produce retrace lines. Before that you must check why the HOT is so hot. Could it be the B+ voltage is too high or the signal pulse to base of HOT is abnormal or if the flyback itself have problem?

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Hi Jestine , Thankyou for the info on the dvd video machine , i checked the power suply and found the 5 volt line to one of the chips rather low due to a resister loosing value in other words it was open circuit causing a loss of voltage to one of the chips also on checking the tape mechanism i fount that one of the cogs were out of line , Thanks once again .

James

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can i  replace the diode (RL-205) with (RL-207)
because i our area  RL205 is not available and  RL207 has 1000 peak reverse voltage while RL-205 has 600 peak reverse coltage…..
please replay me

regards
R.mohammed ali

Hi Mohammed,

If the ampere is the same yes you can replace it.

Jestine

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Hi,

Jestine thanks for your reply. How can I check if the power supply is stable bcz I don’t have any oscilloscope meter,but I have a sanwa meter CX 506A where I can trace any defect in cap [ESR].I’ve already change all the cap in the ps.I’m sure that the ps is not ok but don’t know where is the culprit?
Thanks and regards…………..

Hi Bobby,

If you get the exact voltage from your meter and the needle did not move (constant) then you know you have a good and stable voltage.

Jestine

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