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17MB25-3, blinking led

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papisco:
Hello every one, I have a Techwood model 32832, with a vestel board 17MB25-3, when the tv is powered up, the standby led comes on, and after few second it starts to blick, but the tv does not come on, nothing happens on the screen. I have looked at the PSU ,but no bulgy capacitors, I have also chechked the output voltages from the power supply, but thet are no atable, they keep on going up and down. Please can anyone help, ANY SUGESTIONS.
Thanks

chappers:
Do you have all voltages present (3.3, 5, 12, 24)? Which ones are going up and down exactly?

Here are some solutions for this fault I have listed for this model and chassis:


* Check microfuse FS105 on main board, near CAM module.
* Check SMD fuse FS106 (4A) for open-circuit. Check diodes D881 and D893 (UF5402) for short-circuit.
* 24V rail might be short-circuit, disconnect inverter board supply to prove. Check and replace dual N-channel MOSFETs IC803 and IC804.
* Replace IC830 (FAN7711 and SMD capacitor C925 (1nF).
* Check for short-circuit between pin 6 and pin 8 of IC830 (FAN7711). Replace IC830 and SMD capacitor C833 (100nF).
* Check and replace SMD transistor Q839 (BC859).
* Check D893 and D891 (UF5402) in centre of PSU for short-circuit.
* Voltage at regulator U122 varies between 4V and 9V instead of being stable at 8V. Replace U122 (LM1117ADJ) on main board.
* Check C961 (470uF/35V) at top of PSU.
* Check D893 and R1036 (2.2K) on PSU.
* Replace IC830 (FAN7711).
* Check D893 and its feed resistor. Replace MOSFETs Q813 and Q814 and IC830. Replace C828.
* Replace C892 (100uF), C801 (33uF), C840 (33uF).

WILLYAM1:
what is yourpwer supply?

Turnip:
Hi Chappers,

Go along with Willyam as find nothing in my files or Quuq back threads on that Techwood 32832.  Thanks for the gen  - Chris.

sparky:
hi
looks like 17pw20-1?
dave

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