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Pentranic 1132 (CH-288) No Picture & Chirping - [FIXED!!!!!!]
grantspain:
the fet is q501(K1507-01)
vert ic is IC2(ha11235)
all on the main chassis,the fet is near where the mains input plug
gokun:
thanks grantspain....I'm really struggling with this, so I appreciate the help.
grantspain:
we always want to think that a repair is gonna be easy and 9 times outta 10 it is,seems like you got a bit of a difficult one-the advice is not to give up and follow the advice of the techs here
sometimes it is better to send for repair if you do not have the patience or experience
gokun:
Honestly I have considered just taking it to someone locally and seeing what they can do, but I'll feel like a complete failure if I do that....so I'm going to take to heart your statement on patience and just keep at it for a while....after all I am never going to learn anything if I give up, right? ;)
During my lunch break today I decided to take a fresh start at it and re-check all the capacitors again...this time I used a 25x magnifying lamp with a flourescent light around it (before I only used DMM and didn't do a very good visual inspection in my opinion)so I could see everything really really really well....and....
I think I found 2 blown capacitors after all....one is what appears to be the main one(400v 220uf biggest one in physical size on the board)...don't have the schematic in front of me right now, but plan on taking some pics tonight anyhoo so will update with the ID from the schematic then as well...at any rate, although it tests within tolerance on a DMM(well, as much as is possible at any rate), the top of it upon close inspection is bulging out, which I understand means it is toast...
now here's where I get confused again...there is another part, which looks similar to a capacitor except all it says on it is "25uH LL00015"....this is an inductor or something maybe?? it's almost like an hourglass shape, but it has ridges in it like it collapsed on itself or something...the ridges are irregular in appearance as well...
At any rate, there is copper visible(e.g. you can see the insides of it)through a small hole in the side, and towards the bottom there is more visible and it looks almost scratched or something...unfortunately it's up against another piece so will not be able to get a good look until tonight some time....sigh....and of course what I see may not turn out to be copper at all....who knows...
but I am going to post pics of the 2 parts to see what you guys think....I am fairly sure that the capacitor is bad, but have no idea on the other part....it just looks bad to my eyeballs...
also plan on doing the other suggested tests tonight or tomorrow on the vert ic, fet, etc. (thanks grantspain-I found them!)and will post my results....
so don't give up on me guys-I'm determined!
Rickn:
So did you do anything as far as C313 and C501??
i would suggest that you change them both as they are likely leaky or off value.
yes I can quote you on a new board, but seemed like you were determined to find the problem and learn something... every day you learn something is a good day.
If you want a price e-mail me rick@niemandisplays.com-> be sure to give me a ship to address.
good Luck
Rick