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FIXED - Sanyo TV + 17PW20.1

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dumpystig:
OK, after trying the 'Menu-4-7-2-5' trick all that's happened is the LED is now at full illumination constantly with standby button pressed in; neither remote or side buttons have any effect.

Voltages at present state:

PL805
- Pin 11 - 3.3V
- Pin 12 - 3.3V
- Pin 13 - 5V

PL806
- Pin 6 - 54.7mV

So the 'run V' is not present... maybe this indicates a fault on the 17MB22-2? It seems as though something needs to warm up before standby will kick-in...

I've read about checking the small side button board, it's 3.3V at the Zener and 8.6V at the input from PL811 on the PSU.

watteau:
Hi,

Yes, it sounds like a main PCB problem, have you tried warming
the main PCB with a hairdryer to see if that will localise the problem?

Here's a link to some info. I found about this chassis:
http://www.megaupload.com/?d=ER9AMF73

Regards,
John

dumpystig:
Hey John, that's a great find, I've searched everywhere for a service manual but there's very little Sanyo literature out there. Although it's for a different model after a quick glance I'm sure it will be a great help to me. I made a chart of all voltages last night so I can do some cross referencing and should be able to pinpoint the fault, or at least narrow it down somewhat. Hopefully when I return I can post the fix for future reference.

Thanks again pal,
Mark
 

dumpystig:
FIXED - 17MB22-2 Chassis, 17PW20.1 PSU.

I've done tons of searching on this topic and both these boards, and I mean tons. The link that John watteau gave me helped with some extra reference voltages. There was incorrect voltage @ PL803, pin6 - should be 1V7 standby but was only 58mV. I got a few pointers from this site (although for a different board), and also from a Russian site, even though the translation wasn't brilliant!
It turned out there were quite a few dry joints so, besides all the major heavy joints I did at first, the following are where I had success, all on the PSU:

- Q804, Q805 - part of ST_BY/ON/OFF circuit
- R913, R914, R915

I'm still only getting 334V @ run across C819, not 390V as indicated on circuit diagram, but all other V's are fine.

Many thanks to you John, that d/l link you gave me helped a lot.


 

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